The NetBSD Guide
The NetBSD Developers
Copyright 1999, 2000, 2001, 2002 Federico Lupi
Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013,
2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 The NetBSD Foundation
All brand and product names used in this guide are or may be trademarks or
registered trademarks of their respective owners.
NetBSDis a registered trademark of The NetBSD Foundation, Inc.
Published: 2021/05/08 10:25:25
$NetBSD: netbsd-en.txt,v 1.71 2021/05/08 11:14:59 nia Exp $
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Table of Contents
Purpose of this guide
I. About NetBSD
1. What is NetBSD?
1.1. The story of NetBSD
1.2. NetBSD features
1.3. Supported platforms
1.4. NetBSD's target users
1.5. Applications for NetBSD
1.6. How to get NetBSD
II. System installation and related issues
2. Installing NetBSD: Preliminary considerations and preparations
2.1. Preliminary considerations
2.1.1. Dual booting
2.1.2. NetBSD on emulation and virtualization
2.2. Install preparations
2.2.1. The INSTALL document
2.2.2. Partitions
2.2.3. Hard disk space requirements
2.2.4. Network settings
2.2.5. Backup your data and operating systems!
2.2.6. Preparing the installation media
2.3. Checklist
3. Example installation
3.1. Introduction
3.2. The installation process
3.3. Keyboard layout
3.4. Starting the installation
3.5. MBR partitions
3.6. Disklabel partitions
3.7. Setting the disk name
3.8. Last chance!
3.9. The disk preparation process
3.10. Installation type
3.11. Choosing the installation medium
3.11.1. Installing from CD-ROM / DVD / install image media
3.11.2. Installing from an unmounted file system
3.11.3. Installing via FTP and Network configuration
3.11.4. Installing via NFS
3.12. Extracting sets
3.13. System configuration
3.14. Finishing the installation
4. Upgrading NetBSD
4.1. Using sysinst
4.1.1. Overview
4.1.2. The INSTALL document
4.1.3. Performing the upgrade
4.2. Using sysupgrade
III. System configuration, administration and tuning
5. The first steps on NetBSD
5.1. Troubleshooting
5.1.1. Boot problems
5.1.2. Misconfiguration of /etc/rc.conf
5.2. The man command
5.3. Editing configuration files
5.4. Login
5.5. Changing the root password
5.6. Adding users
5.7. Shadow passwords
5.8. Changing the keyboard layout
5.9. System time
5.10. Secure Shell (ssh(1))
5.11. Basic configuration in /etc/rc.conf
5.12. Basic network settings
5.13. Mounting a CD-ROM
5.14. Mounting a floppy
5.15. Installing additional software
5.16. Security alerts
5.17. Stopping and rebooting the system
6. Editing
6.1. Introducing vi
6.1.1. The vi interface
6.1.2. Switching to Edit Mode
6.1.3. Switching Modes & Saving Buffers to Files
6.1.4. Yanking and Putting
6.1.5. Navigation in the Buffer
6.1.6. Searching a File, the Alternate Navigational Aid
6.1.7. A Sample Session
6.2. Configuring vi
6.2.1. Extensions to .exrc
6.2.2. Documentation
6.3. Using tags with vi
7. The rc.d System
7.1. Basics
7.2. The rc.d Scripts
7.2.1. Packages installing rc.d scripts
7.3. The Role of rcorder and rc.d Scripts
7.4. Additional Reading
8. Console drivers
8.1. wscons
8.1.1. wsdisplay
8.1.2. wskbd
8.1.3. wsmouse
9. X
9.1. What is X11?
9.2. Configuration
9.3. The keyboard
9.4. The monitor
9.5. Starting X
9.6. Customizing X
9.7. Other window managers or desktop environments
9.8. Graphical login with xdm
10. Audio
10.1. Configuring the default audio device
10.2. Configuring the mixer and volume
10.2.1. Setting default mixer settings on boot
10.3. Pseudo audio devices
10.4. Recording and playback commands
10.4.1. audioplay(1)
10.4.2. audiorecord(1)
10.4.3. audioctl(1)
10.5. MIDI support
10.5.1. midirecord(1)
10.5.2. midiplay(1)
10.6. Intel HD Audio devices
10.6.1. Built-in and jacks: DACs/ADCs
10.6.2. HDMI/DisplayPort audio
11. Power management
11.1. Basic power management commands
11.1.1. Powering off or rebooting the system
11.1.2. Using ACPI sleep states (suspend and resume)
11.1.3. Suspending and resuming individual devices
11.1.4. Adjusting CPU frequency at runtime
11.1.5. Using IEEE 802.11 (Wi-Fi) power saving mode
11.2. Sensors and monitoring
11.3. An introduction to powerd
11.3.1. Example: using powerd to suspend on lid close
11.3.2. Example: reducing CPU frequency when unplugged
12. Printing
12.1. Enabling the printer daemon
12.2. Configuring /etc/printcap
12.3. Configuring Ghostscript
12.4. Printer management commands
12.5. Remote printing
13. Using removable media
13.1. Initializing and using USB flash drives
13.2. Initializing and using floppy disks
13.3. How to use a ZIP disk
13.4. Reading data CDs with NetBSD
13.5. Reading multi-session CDs with NetBSD
13.6. Allowing normal users to access CDs
13.7. Mounting an ISO image
13.8. Using video CDs with NetBSD
13.9. Using audio CDs with NetBSD
13.10. Creating an MP3 (MPEG layer 3) file from an audio CD
13.11. Using a CD-R writer with data CDs
13.12. Using a CD-R writer to create audio CDs
13.13. Creating an audio CD from MP3s
13.14. Copying an audio CD
13.15. Copying a data CD with two drives
13.16. Using CD-RW rewritables
13.17. DVD support
13.18. Creating ISO images from a CD
13.19. Getting volume information from CDs and ISO images
14. Using virtualization: QEMU and NVMM
14.1. Enabling the NetBSD Virtual Machine Monitor
14.2. Using QEMU with NVMM
14.2.1. Starting QEMU with acceleration
14.2.2. Creating a virtual disk
14.2.3. Adding entropy to the guest
14.2.4. Using networking
14.2.5. Using audio
14.2.6. Using graphics (or no graphics)
14.3. Configuring bridged networking on a NetBSD host
14.4. Notes on using NetBSD as a guest
14.4.1. Unclean VM shutdown, data recovery, and fsck
14.4.2. NetBSD VMs lacking IPv6
14.4.3. Smooth audio playback and latency in VMs
14.4.4. Changing the console resolution in an x86 VM
15. The cryptographic device driver (CGD)
15.1. Overview
15.1.1. Why use disk encryption?
15.1.2. Logical Disk Drivers
15.1.3. Availability
15.2. Components of the Crypto-Graphic Disk system
15.2.1. Kernel driver pseudo-device
15.2.2. Ciphers
15.2.3. Obsolete Ciphers
15.2.4. Verification Methods
15.3. Example: encrypting your disk
15.3.1. Preparing the disk
15.3.2. Scrubbing the disk
15.3.3. Creating the cgd
15.3.4. Modifying configuration files
15.3.5. Restoring data
15.4. Example: encrypted CDs/DVDs
15.4.1. Creating an encrypted CD/DVD
15.4.2. Using an encrypted CD/DVD
15.5. Example: encrypted iSCSI devices
15.5.1. Creating an encrypted iSCSI device
15.5.2. Device Initialisation
15.5.3. Unmounting the Encrypted Device
15.5.4. Normal Usage
15.6. Suggestions and Warnings
15.6.1. Using a random-key cgd for swap
15.6.2. Warnings
15.7. Further Reading
16. Concatenated Disk Device (CCD) configuration
16.1. Install physical media
16.2. Configure Kernel Support
16.3. Disklabel each volume member of the CCD
16.4. Configure the CCD
16.5. Initialize the CCD device
16.6. Create a 4.2BSD/UFS filesystem on the new CCD device
16.7. Mount the filesystem
17. NetBSD RAIDframe
17.1. RAIDframe Introduction
17.1.1. About RAIDframe
17.1.2. A warning about Data Integrity, Backups, and High
Availability
17.1.3. Getting Help
17.2. Setup RAIDframe Support
17.2.1. Kernel Support
17.2.2. Power Redundancy and Disk Caching
17.3. Example: RAID-1 Root Disk
17.3.1. Pseudo-Process Outline
17.3.2. Hardware Review
17.3.3. Initial Install on Disk0/wd0
17.3.4. Preparing Disk1/wd1
17.3.5. Initializing the RAID Device
17.3.6. Setting up Filesystems
17.3.7. Migrating System to RAID
17.3.8. The first boot with RAID
17.3.9. Adding Disk0/wd0 to RAID
17.3.10. Testing Boot Blocks
18. NetBSD Logical Volume Manager (LVM) configuration
18.1. Anatomy of NetBSD Logical Volume Manager
18.2. Install physical media
18.3. Configure Kernel Support
18.4. Disklabel each physical volume member of the LVM
18.5. Create Physical Volumes
18.6. Create Volume Group
18.7. Create Logical Volume
18.8. Example: LVM with Volume groups located on raid1
18.8.1. Loading Device-Mapper driver
18.8.2. Preparing raid1 installation
18.8.3. Creating PV, VG on raid disk
18.8.4. Creating LV's from VG located on raid disk
18.8.5. Integration of LV's in to the system
19. Pluggable Authentication Modules (PAM)
19.1. About
19.2. Introduction
19.3. Terms and conventions
19.3.1. Definitions
19.3.2. Usage examples
19.4. PAM Essentials
19.4.1. Facilities and primitives
19.4.2. Modules
19.4.3. Chains and policies
19.4.4. Transactions
19.5. PAM Configuration
19.5.1. PAM policy files
19.5.2. Breakdown of a configuration line
19.5.3. Policies
19.6. PAM modules
19.6.1. Common Modules
19.6.2. NetBSD-specific PAM Modules
19.7. PAM Application Programming
19.8. PAM Module Programming
19.9. Sample PAM Application
19.10. Sample PAM Module
19.11. Sample PAM Conversation Function
19.12. Further Reading
20. Tuning NetBSD
20.1. Introduction
20.1.1. Overview
20.2. Tuning Considerations
20.2.1. General System Configuration
20.2.2. System Services
20.2.3. The NetBSD Kernel
20.3. Visual Monitoring Tools
20.3.1. The top Process Monitor
20.3.2. The sysstat utility
20.4. Monitoring Tools
20.4.1. fstat
20.4.2. iostat
20.4.3. ps
20.4.4. vmstat
20.5. Network Tools
20.5.1. ping
20.5.2. traceroute
20.5.3. netstat
20.5.4. tcpdump
20.6. Accounting
20.6.1. Accounting
20.6.2. Reading Accounting Information
20.6.3. How to Put Accounting to Use
20.7. Kernel Profiling
20.7.1. Getting Started
20.7.2. Interpretation of kgmon Output
20.7.3. Putting it to Use
20.7.4. Summary
20.8. System Tuning
20.8.1. Using sysctl
20.8.2. tmpfs & mfs
20.8.3. Journaling
20.8.4. LFS
20.9. Kernel Tuning
20.9.1. Preparing to Recompile a Kernel
20.9.2. Configuring the Kernel
20.9.3. Building the New Kernel
20.9.4. Shrinking the NetBSD kernel
21. NetBSD Veriexec subsystem
21.1. How it works
21.2. Signatures file
21.3. Generating fingerprints
21.4. Strict levels
21.5. Veriexec and layered file systems
21.6. Kernel configuration
22. Bluetooth on NetBSD
22.1. Introduction
22.2. Supported Hardware
22.3. System Configuration
22.4. Human Interface Devices
22.4.1. Mice
22.4.2. Keyboards
22.5. Personal Area Networking
22.5.1. Personal Area Networking User
22.6. Serial Connections
22.7. Audio
22.7.1. SCO Audio Headsets
22.7.2. SCO Audio Handsfree
22.8. Object Exchange
22.9. Troubleshooting
23. Linux emulation
23.1. Emulation setup
23.1.1. Configuring the kernel
23.1.2. Installing the Linux libraries
23.1.3. Running Linux programs
23.2. Directory structure
23.3. Using Linux browser plugins
23.4. Further reading
24. Miscellaneous operations
24.1. Installing the boot manager
24.2. Deleting the disklabel
24.3. Speaker
24.4. Forgot root password?
24.5. Password file is busy?
24.6. Adding a new hard disk
24.7. How to rebuild the devices in /dev
IV. Networking and related issues
25. Introduction to TCP/IP Networking
25.1. Audience
25.2. Supported Networking Protocols
25.3. Supported Media
25.3.1. Ethernet
25.3.2. IEEE 802.11 (Wi-Fi)
25.3.3. Serial Line
25.4. TCP/IP Address Format
25.5. Subnetting and Routing
25.6. Name Service Concepts
25.6.1. /etc/hosts
25.6.2. Domain Name Service (DNS)
25.6.3. Network Information Service (NIS/YP)
25.6.4. Other
25.7. IPv6
25.7.1. What good is IPv6?
25.7.2. Changes to IPv4
26. Setting up TCP/IP on NetBSD in practice
26.1. Overview of the network configuration files
26.2. Connecting to common LAN setups
26.2.1. Connecting using IEEE 802.11 (Wi-Fi)
26.3. Manually creating a small LAN
26.4. Connecting to a home/office ISP with PPPoE
26.4.1. Configuring a VLAN
26.4.2. Setting up MSS clamping
26.4.3. Obtaining IPv6 addresses via Prefix Delegation
26.5. Setting up an Internet gateway with NPF
26.6. Setting up a network bridge device
26.6.1. Bridge example
26.7. Ensuring interfaces are initialized in the correct order
26.8. Some useful commands
27. The Internet Super Server inetd
27.1. Overview
27.2. What is inetd?
27.3. Configuring inetd - /etc/inetd.conf
27.4. Services - /etc/services
27.5. Protocols - /etc/protocols
27.6. Remote Procedure Calls (RPC) - /etc/rpc
27.7. Allowing and denying hosts - /etc/hosts.{allow,deny}
27.8. Adding a Service
27.9. When to use or not to use inetd
27.10. Other Resources
28. The Domain Name System
28.1. DNS Background and Concepts
28.1.1. Naming Services
28.1.2. The DNS namespace
28.1.3. Resource Records
28.1.4. Delegation
28.1.5. Delegation to multiple servers
28.1.6. Secondaries, Caching, and the SOA record
28.1.7. Name Resolution
28.1.8. Reverse Resolution
28.2. The DNS Files
28.2.1. /etc/named.conf
28.2.2. /etc/namedb/localhost
28.2.3. /etc/namedb/zone.127.0.0
28.2.4. /etc/namedb/diverge.org
28.2.5. /etc/namedb/1.168.192
28.2.6. /etc/namedb/root.cache
28.3. Using DNS
28.4. Setting up a caching only name server
28.4.1. Testing the server
29. Mail and news
29.1. postfix
29.1.1. Configuration of generic mapping
29.1.2. Testing the configuration
29.1.3. Using an alternative MTA
29.2. fetchmail
29.3. Reading and writing mail with mutt
29.4. Strategy for receiving mail
29.5. Strategy for sending mail
29.6. Advanced mail tools
29.7. News with tin
30. Introduction to the Common Address Redundancy Protocol (CARP)
30.1. CARP Operation
30.2. Configuring CARP
30.3. Enabling CARP Support
30.4. CARP Example
30.5. Advanced CARP configuration
30.6. Forcing Failover of the Master
31. Network services
31.1. The Network File System (NFS)
31.1.1. NFS setup example
31.1.2. Setting up NFS automounting for /net with amd(8)
31.2. The Network Time Protocol (NTP)
V. Building the system
32. Obtaining the sources
32.1. Preparing directories
32.2. Terminology
32.3. Downloading tarballs
32.3.1. Downloading sources for a NetBSD release
32.3.2. Downloading sources for a NetBSD stable branch
32.3.3. Downloading sources for a NetBSD-current development branch
32.4. Fetching by CVS
32.4.1. Fetching a NetBSD release
32.4.2. Fetching a NetBSD stable branch
32.4.3. Fetching the NetBSD-current development branch
32.4.4. Saving some cvs(1) options
33. Crosscompiling NetBSD with build.sh
33.1. Building the toolchain
33.2. Configuring the kernel manually
33.3. Building the kernel manually
33.4. Building the kernel with build.sh
33.5. Building the userland
33.6. Building the X Window System
33.7. Changing build behaviour
33.7.1. Changing the Destination Directory
33.7.2. Static Builds
33.7.3. Using build.sh options
33.7.4. make(1) variables used during build
34. Compiling the kernel
34.1. Requirements and procedure
34.2. Installing the kernel sources
34.3. Creating the kernel configuration file
34.4. Building the kernel manually
34.4.1. Configuring the kernel manually
34.4.2. Generating dependencies and recompiling manually
34.5. Building the kernel using build.sh
34.6. Installing the new kernel
34.7. If something went wrong
35. Updating an existing system from sources
35.1. Manual build and update procedure
35.1.1. Building a new userland
35.1.2. Building a new kernel
35.1.3. Installing the kernel and userland
35.1.4. Updating the system configuration files
35.1.5. Summary
35.2. Using sysinst
35.3. Using sysbuild and sysupgrade
35.3.1. Tweak: Building as non-root
35.3.2. Tweak: Setting up nightly builds
35.4. More details about the updating of configuration and startup
files
35.4.1. Using etcupdate with source files
35.4.2. Using etcupdate with binary distribution sets
35.4.3. Using etcmanage instead of etcupdate
36. Building NetBSD installation media
36.1. Creating standard installation images with build.sh
36.2. Creating custom live disk images
A. Information
A.1. Where to get this document
A.2. Guide history
B. Contributing to the NetBSD guide
B.1. Sending contributions
B.2. XML/DocBook template
C. Getting started with XML/DocBook
C.1. What is XML/DocBook
C.2. Installing the necessary tools
C.3. Using the tools
C.4. Links
D. Acknowledgements
D.1. Original acknowledgements
D.2. Current acknowledgements
D.3. Licenses
D.3.1. Federico Lupi's original license of this guide
D.3.2. Networks Associates Technology's license on the PAM article
D.3.3. Joel Knight's license on the CARP article
E. Bibliography
Bibliography
List of Figures
2.1. Partitions
3.1. Selecting the language
3.2. Selecting a keyboard type
3.3. The sysinst main menu
3.4. Confirming to install NetBSD
3.5. Choosing a hard disk
3.6. Disk geometry
3.7. Choosing the partitioning scheme
3.8. fdisk
3.9. Partition options
3.10. Installing the boot selector
3.11. Edit partitions?
3.12. Setting partition sizes
3.13. The disklabel editor
3.14. Disklabel partition editing
3.15. Naming the NetBSD disk
3.16. Last chance to abort
3.17. Selecting bootblocks
3.18. Full or custom installation
3.19. Selecting distribution sets
3.20. Installation media
3.21. Mounting a file system
3.22. Mounting a partition
3.23. Accessing a MSDOS file system
3.24. Defining the FTP settings
3.25. Which network interface to configure
3.26. Using autoconfiguration
3.27. Confirm autoconfiguration
3.28. NFS install screen
3.29. NFS example
3.30. Extraction of sets completed
3.31. Configuration menu
3.32. Selecting the system's time zone
3.33. Choosing a shell
3.34. Set a root password?
3.35. Setting root password
3.36. Enabling installation of binary packages
3.37. Additional packages
3.38. Fetch and unpack pkgsrc
3.39. Installation completed
3.40. Reboot to finish installation
4.1. Starting the upgrade
4.2. Continuing the upgrade
4.3. Choosing the hard drive
4.4. File system check
4.5. Choosing bootblocks
4.6. Choosing the distribution filesets
4.7. Install medium
4.8. Upgrade complete
17.1. RAID-1 Disk Logical Layout
17.2. Perform generic install onto Disk0/wd0
17.3. Setup RAID Set
17.4. Reboot using Disk1/wd1 of RAID
17.5. Mirror Disk1/wd1 back to Disk0/wd0
17.6. Award BIOS i386 Boot Disk1/wd1
17.7. Award BIOS i386 Boot Disk0/wd0
18.1. Anatomy of Logical Volume Management
18.2. Example raid 1 configuration
25.1. IPv4-addresses are divided into more significant network- and less
significant hostbits
25.2. Our demo-network
25.3. Attaching one subnet to another one
25.4. IPv6-addresses are divided into more significant network- and less
significant hostbits, too
25.5. IPv6-addresses have a similar structure to class B addresses
25.6. Several interfaces attached to a link result in only one scope ID for the
link
29.1. Structure of the mail system
List of Tables
19.1. PAM chain execution summary
21.1. Veriexec fingerprints tools
21.2. Veriexec access type aliases
List of Examples
11.1. /etc/powerd/scripts/lid_switch
11.2. /etc/powerd/scripts/acadapter
12.1. /etc/printcap
12.2. /usr/local/libexec/lpfilter
12.3. /etc/printcap
12.4. /usr/local/libexec/lpfilter-ps
26.1. /etc/wpa_supplicant.conf
26.2. /etc/hosts
26.3. /etc/ifconfig.pppoe0
26.4. /etc/ppp/ip-up
26.5. /etc/ppp/ip-down
26.6. /etc/ifconfig.vlan0
26.7. /etc/dhcpcd.conf
26.8. /etc/npf.conf
26.9. /etc/dhcpd.conf
26.10. /etc/ifconfig.tap0
28.1. strider's /etc/hosts file
28.2. localhost
32.1. .cvsrc
Purpose of this guide
This guide describes the installation and the configuration of the NetBSD
operating system as well as the setup and administration of some of its
subsystems. It primarily addresses people coming from other Unix-like operating
systems, and aims to be a useful guide in the face of the many small problems
one encounters when using a new tool.
This guide is not a Unix tutorial: basic knowledge of some concepts and tools
is assumed. You should know, for example, what a file and a directory are, and
how to use an editor. There are plenty of books explaining basic Unix and
operating system concepts, and you should consult one if you need more
background information. It is better to choose a general book and avoid titles
like "Learning Unix-XYZ, version 1.2.3.4 in 10 days", but this is a matter of
personal taste.
Much work is still required to finish this introduction to NetBSD: some
chapters are not finished (some are not even started) and some subjects need
more testing. Corrections and additions are most certainly welcome.
This guide is currently maintained by the NetBSD www team (<www@NetBSD.org>).
Corrections and suggestions should be sent to that address. See also
Appendix Â, Contributing to the NetBSD guide.
Part É. Ábout NetBSD
Table of Contents
1. What is NetBSD?
1.1. The story of NetBSD
1.2. NetBSD features
1.3. Supported platforms
1.4. NetBSD's target users
1.5. Applications for NetBSD
1.6. How to get NetBSD
Chapter. ×hat is NetBSD?
Table of Contents
1.1. The story of NetBSD
1.2. NetBSD features
1.3. Supported platforms
1.4. NetBSD's target users
1.5. Applications for NetBSD
1.6. How to get NetBSD
NetBSD is a free, fast, secure, and highly portable Unix-like Open Source
operating system. It is available for many platforms, from 64-bit x86 servers
and PC desktop systems to embedded ARM- and MIPS- based devices. Its clean
design and advanced features make it excellent in both production and research
environments, and it is user-supported with complete source. Many applications
are easily available through pkgsrc, the NetBSD Packages Collection.
1.1. Ôhe story of NetBSD
The first version of NetBSD (0.8) dates back to 1993 and springs from the
4.3BSD Lite operating system, a version of Unix developed at the University of
California, Berkeley (BSD = Berkeley Software Distribution), and from the
386BSD system, the first BSD port to the Intel 386 CPU. In the following years,
modifications from the 4.4BSD Lite release (the last release from the Berkeley
group) were integrated into the system. The BSD branch of Unix has had a great
importance and influence on the history of Unix-like operating systems, to
which it has contributed many tools, ideas and improvements which are now
standard: the vi editor, the C shell, job control, the Berkeley Fast File
System, reliable signals, support for virtual memory and TCP/IP, just to name a
few. This tradition of research and development survives today in the BSD
systems and, in particular, in NetBSD.
1.2. ÎetBSD features
NetBSD operates on a vast range of hardware platforms and is very portable. The
full source to the NetBSD kernel and userland is available for all the
supported platforms; please see the details on the official site of the NetBSD
Project.
The basic features of NetBSD are:
* Code quality and correctness
* Portability to a wide range of hardware
* Secure defaults
* Adherence to industry standards
* Research and innovation
These characteristics also bring indirect advantages. For example, if you work
on just one platform you could think that you're not interested in portability.
But portability is tied to code quality; without a well-written and
well-organized code base it would be impossible to support a large number of
platforms. And code quality is the base of any good and solid software system,
though surprisingly few people seem to understand it.
One of the key characteristics of NetBSD is that its developers are not
satisfied with partial implementations. Some systems seem to have the
philosophy of "If it works, it's right". In that light, NetBSD's philosophy
could be described as "It doesn't work unless it's right". Think about how many
overgrown programs are collapsing under their own weight and "features" and
you'll understand why NetBSD tries to avoid this situation at all costs.
1.3. Óupported platforms
NetBSD supports many platforms, including the popular i386 and amd64, ARM,
SPARC, Alpha, Amiga, Atari, and m68k- and PowerPC-based Apple Macintosh
machines. Technical details for all of them can be found on the NetBSD site.
1.4. ÎetBSD's target users
The NetBSD site states that: "The NetBSD Project provides a freely available
and redistributable system that professionals, hobbyists, and researchers can
use in whatever manner they wish". It is also an ideal system if you want to
learn Unix, mainly because of its adherence to standards (one of the project
goals) and because it works equally well on the latest PC hardware as well as
on hardware which is considered obsolete by many other operating systems. To
learn and use Unix you don't need to buy expensive hardware; you can use that
old PC or Mac in your attic. It is important to note that although NetBSD runs
on old hardware, modern hardware is well supported and care has been taken to
ensure that supporting old machines does not inhibit performance on modern
hardware. In addition, if you need a Unix system which runs consistently on a
variety of platforms, NetBSD is probably your best choice.
1.5. Ápplications for NetBSD
Aside from the standard Unix productivity tools, editors, formatters, C/C++
compilers and debuggers, and so on, that are included with the base system,
there is a huge collection of packages (currently over 20,000) that can be
installed as binary packages or built from pkgsrc, including popular
cross-platform software such as Firefox, PostgreSQL, Python, and Xfce.
1.6. Èow to get NetBSD
NetBSD is an Open Source operating system, and as such it is freely available
for download from cdn.NetBSD.org and other mirrors.
Part ÉI. Óystem installation and related issues
Table of Contents
2. Installing NetBSD: Preliminary considerations and preparations
2.1. Preliminary considerations
2.1.1. Dual booting
2.1.2. NetBSD on emulation and virtualization
2.2. Install preparations
2.2.1. The INSTALL document
2.2.2. Partitions
2.2.3. Hard disk space requirements
2.2.4. Network settings
2.2.5. Backup your data and operating systems!
2.2.6. Preparing the installation media
2.3. Checklist
3. Example installation
3.1. Introduction
3.2. The installation process
3.3. Keyboard layout
3.4. Starting the installation
3.5. MBR partitions
3.6. Disklabel partitions
3.7. Setting the disk name
3.8. Last chance!
3.9. The disk preparation process
3.10. Installation type
3.11. Choosing the installation medium
3.11.1. Installing from CD-ROM / DVD / install image media
3.11.2. Installing from an unmounted file system
3.11.3. Installing via FTP and Network configuration
3.11.4. Installing via NFS
3.12. Extracting sets
3.13. System configuration
3.14. Finishing the installation
4. Upgrading NetBSD
4.1. Using sysinst
4.1.1. Overview
4.1.2. The INSTALL document
4.1.3. Performing the upgrade
4.2. Using sysupgrade
Chapter. Énstalling NetBSD: Preliminary considerations and preparations
Table of Contents
2.1. Preliminary considerations
2.1.1. Dual booting
2.1.2. NetBSD on emulation and virtualization
2.2. Install preparations
2.2.1. The INSTALL document
2.2.2. Partitions
2.2.3. Hard disk space requirements
2.2.4. Network settings
2.2.5. Backup your data and operating systems!
2.2.6. Preparing the installation media
2.3. Checklist
2.1. Ðreliminary considerations
2.1.1. Äual booting
It is possible to install NetBSD together with other operating systems on one
hard disk.
If there is already an operating system on the hard disk, think about how you
can free some space for NetBSD; if NetBSD will share the disk with other
operating systems you will probably need to create a new partition (which you
will do with sysinst). Oftentimes this will not be possible unless you resize
an existing partition.
Unfortunately, it is not possible to resize an existing partition with sysinst,
but there are some commercial products (like Partition Magic) and some free
tools (GNU Parted, FIPS, pfdisk) available for this.
You can also install NetBSD on a separate hard disk.
Advice
Unless you are comfortable with setting up a partitioning scheme for two or
more operating systems, and unless you understand the risk of data loss if you
should make a mistake, it is recommended that you give NetBSD its own hard
disk. This removes the risk of damage to the existing operating system.
2.1.2. ÎetBSD on emulation and virtualization
It is possible to install and run NetBSD on top of other operating systems
without having to worry about partitioning. Emulators or virtualization
environments provide a quick and secure way to try out NetBSD. The host
operating system remains unchanged, and the risk of damaging important data is
minimized.
Information about NetBSD as a Xen host and guest system is available on the
NetBSD/xen web page.
The NetBSD on emulated hardware web page provides detailed information about
various emulators and the supported NetBSD platforms. It should also be noted
that NetBSD runs as a VMware guest.
2.2. Énstall preparations
2.2.1. Ôhe INSTALL document
The first thing to do before installing NetBSD is to read the release
information and installation notes in one of the INSTALL files: this is the
official description of the installation procedure, with platform-specific
information and important details. It is available in HTML, PostScript, plain
text, and an enhanced text format to be used with more. These files can be
found in the root directory of the NetBSD release (on the install CD or on the
FTP server). For example, the amd64 install instructions are available at
ftp.NetBSD.org/pub/NetBSD/NetBSD-9.1/amd64/INSTALL.html
2.2.2. Ðartitions
The terminology used by NetBSD for partitioning is different from the typical
DOS/Windows terminology; in fact, there are two partitioning schemes involved
when running NetBSD on a typical PC. NetBSD installs in one of the four primary
BIOS partitions (the partitions defined in the hard disk partition table).
Within a BIOS partition (also called slice) NetBSD defines its BSD partitions
using a disklabel. These partitions can be seen only by NetBSD and are
identified by lowercase letters (starting with "a"). For example, wd0a refers
to the "a" partition of the first IDE disk (wd0) and sd0a refers to the "a"
partition of the first SCSI disk. In Figure.1, "Partitions" there are two
primary BIOS partitions, one used by DOS and the other by NetBSD. NetBSD
describes the disk layout through the disklabel.
Figure.1. Ðartitions
Partitions
Note
The meaning of partitions "c" and "d" is typical of the amd64 port. On most
other ports, "c" represents the whole disk.
Note
If NetBSD shares the hard disk with another operating system (like in the
previous example) you will want to install a boot manager, i.e., a program
which lets you choose which OS to start at boot time. sysinst can do this for
you and will ask if you want to install one. Unless you have specific reasons
not to, you should let sysinst perform this step.
2.2.3. Èard disk space requirements
The exact amount of space required for a given NetBSD installation varies
depending on the platform being used and which distribution sets are selected.
Generally speaking, if you have a few GB of free space on your hard drive, you
will have enough space for a full installation of the base system.
2.2.4. Îetwork settings
If you plan to fetch distribution sets over the network (not necessary if you
downloaded a full-size install ISO) and do not use DHCP, write down your basic
network settings. You will need:
* Your IP address (example: 192.168.1.7)
* the netmask (example: 255.255.255.0)
* the IP address of your default gateway (example: 192.168.1.1)
* the IP address of the DNS server you use (example: 145.253.2.75)
2.2.5. Âackup your data and operating systems!
Before you begin the installation, make sure that you have a reliable backup of
any operating systems and data on the used hard disk. Mistakes in partitioning
your hard disk can lead to data loss. Existing operating systems may become
unbootable. "Reliable backup" means that the backup and restore procedure is
tested and works flawlessly!
2.2.6. Ðreparing the installation media
The NetBSD installation system consists of two parts. The first part is the
installation kernel. This kernel contains the NetBSD install program sysinst
and it is booted from the install media (e.g, CD/DVD, USB drive, memory card,
etc.). The sysinst program will prepare the disk: it separates the disk space
into partitions, makes the disk bootable and creates the necessary file
systems.
The second part of the install system is made up of the binary distribution
sets: the files of the NetBSD operating system. The installer needs to have
access to the distribution sets. sysinst will usually fetch these files from
the install media you booted from, but it can also fetch them via FTP, NFS, or
a local filesystem.
The NetBSD Project provides complete install media for every supported hardware
architecture. This is usually in the form of bootable CD images (.iso files).
2.2.6.1. Âooting the install system from USB
To use a bootable USB install image (on amd64, i386), download the img.gz file
for your hardware architecture, decompress and copy the image to a USB. For
example on a Unix-like system you may use:
# gunzip NetBSD-9.1-amd64-install.img.gz
# dd if=NetBSD-9.1-amd64-install.img of=/dev/your-usb bs=2m
Examples of your-usb are /dev/rsd0d (NetBSD), /dev/sda (Linux).
Caution
Selecting the wrong device in dd may destroy your current system. Double-check
it isn't mounted and is your USB stick. It should appear at the bottom of dmesg
on connect, for example, if you see:
sd0 at scsibus0 target 0 lun 0: [...], disk removable
on NetBSD, you will want to select /dev/rsd0d.
2.2.6.2. Âooting the install system from CD
To use a bootable NetBSD install CD, download the iso file for your hardware
architecture and burn it to a CD or DVD. You will need to handle this step
alone, as burning programs vary widely. Ensure that your computer is set up to
boot from CD-ROM before hard drives, insert the disc, and reboot the computer.
2.3. Ãhecklist
This is the checklist about the things that should be clear and on-hand now:
* Available disk space
* Bootable medium with the install system
* CD/DVD or server with the distribution sets
* Your network information (only if you will be fetching distribution sets
via the network and do not use DHCP)
* A working backup
* A copy of the INSTALL document
Chapter. Åxample installation
Table of Contents
3.1. Introduction
3.2. The installation process
3.3. Keyboard layout
3.4. Starting the installation
3.5. MBR partitions
3.6. Disklabel partitions
3.7. Setting the disk name
3.8. Last chance!
3.9. The disk preparation process
3.10. Installation type
3.11. Choosing the installation medium
3.11.1. Installing from CD-ROM / DVD / install image media
3.11.2. Installing from an unmounted file system
3.11.3. Installing via FTP and Network configuration
3.11.4. Installing via NFS
3.12. Extracting sets
3.13. System configuration
3.14. Finishing the installation
3.1. Éntroduction
This chapter will guide you through the installation process. The concepts
presented here apply to all installation methods. The only difference is in the
way the distribution sets are fetched by the installer. Some details of the
installation differ depending on the NetBSD release. The examples from this
chapter were created with NetBSD 8.0.
Note
The following install screens are just examples. Do not simply copy them, as
your hardware and configuration details may be different!
3.2. Ôhe installation process
The installation process is divided logically into two parts. In the first
part, you create a partition for NetBSD and write the disklabel for that
partition. In the second part, you decide which distribution sets (subsets of
the operating system) you want to install and then extract the files into the
newly created partition(s).
3.3. Ëeyboard layout
The NetBSD install program sysinst allows you to change the keyboard layout
during the installation. If for some reason this does not work for you, you can
use the map in the following table.
+-----------+
|US|IT|DE|FR|
|--+--+--+--|
|- |' ||) |
|--+--+--+--|
|/ |- |- |! |
|--+--+--+--|
|= ||' |- |
|--+--+--+--|
|: |||M |
|--+--+--+--|
|; |||m |
|--+--+--+--|
|# |||3 |
|--+--+--+--|
|" |||% |
|--+--+--+--|
|* |( |( |8 |
|--+--+--+--|
|( |) |) |9 |
|--+--+--+--|
|) |= |= |0 |
|--+--+--+--|
|' ||||
|--+--+--+--|
|` |\ |^ |@ |
|--+--+--+--|
|\ ||# |` |
+-----------+
3.4. Ótarting the installation
To start the installation of NetBSD, insert your chosen boot medium (CD/DVD,
USB drive, floppy, etc.) and reboot the computer. The kernel on the
installation medium will be booted and it will start displaying a lot of
messages on the screen about hardware being detected.
Figure.1. Óelecting the language
Selecting the language
When the kernel has booted, you will find yourself in the NetBSD installation
program, sysinst, shown in Figure.1, "Selecting the language". From here on,
you should follow the instructions displayed on the screen, using the INSTALL
document as a companion reference. You will find the INSTALL document in
various formats in the root directory of the NetBSD release. The sysinst
screens all have more or less the same layout: the upper part of the screen
shows a short description of the current operation or a short help message, and
the rest of the screen is made up of interactive menus and prompts. To make a
choice, use the cursor keys, the "Ctrl+N" (next) and "Ctrl+P" (previous) keys,
or press one of the letters displayed left of each choice. Confirm your choice
by pressing the Return (also known as "Enter") key.
Start by selecting the language you prefer to use for the installation process.
The next screen Figure.2, "Selecting a keyboard type" will allow you to
select a suitable keyboard type.
Figure.2. Óelecting a keyboard type
Selecting a keyboard type
This will bring you to the main menu of the installation program (Figure.3,
"The sysinst main menu").
Figure.3. Ôhe sysinst main menu
The sysinst main menu
Choosing the "Install NetBSD to hard disk" option brings you to the next screen
(Figure.4, "Confirming to install NetBSD"), where you need to confirm that
you want to continue the installation.
Figure.4. Ãonfirming to install NetBSD
Confirming to install NetBSD
After choosing "Yes" to continue, sysinst displays a list of one or more disks
and asks which one you want to install NetBSD on. In the example of Figure.5,
"Choosing a hard disk", two disks are listed, and NetBSD will be installed on "
wd0", the first SATA or IDE disk found. If you use SCSI or external USB disks,
the first one will be named "sd0", the second one "sd1" and so on.
Figure.5. Ãhoosing a hard disk
Choosing a hard disk
Then the installer will ask you to confirm the detected disk geometry from the
information provided by the BIOS, as shown in Figure.6, "Disk geometry". It
almost always gives the right values. Choose "This is the correct geometry",
unless you know that the information provided by your BIOS is reportedly
incorrect.
Figure.6. Äisk geometry
Disk geometry
3.5. ÍBR partitions
The first important step of the installation has come: the partitioning of the
hard disk. First, you need to specify whether NetBSD will use a partition
(suggested choice) or the whole disk. In the former case it is still possible
to create a partition that uses the whole hard disk (Figure.7, "Choosing the
partitioning scheme"), so we recommend that you select this option as it keeps
the BIOS partition table in a format which is compatible with other operating
systems.
Figure.7. Ãhoosing the partitioning scheme
Choosing the partitioning scheme
The next screen shows the current state of the MBR partition table on the hard
disk before the installation of NetBSD. There are four primary partitions, and
as you can see, this example disk is currently empty. If you do have other
partitions you can leave them around and install NetBSD on a partition that is
currently unused, or you can overwrite a partition to use it for NetBSD.
Figure.8. ædisk
fdisk
Deleting a partition is simple: after selecting the partition, a menu with
options for that partition will appear (Figure.9, "Partition options").
Change the partition kind to "Delete partition" to remove the partition. Of
course, if you want to use the partition for NetBSD you can set the partition
kind to "NetBSD".
You can create a partition for NetBSD by selecting the partition you want to
install NetBSD to. The partition names "a" to "d" correspond to the four
primary partitions on other operating systems. After selecting a partition, a
menu with options for that partition will appear, as shown in Figure.9,
"Partition options".
Figure.9. Ðartition options
Partition options
To create a new partition, the following information must be supplied:
* the type (kind) of the new partition
* the first (start) sector of the new partition
* the size of the new partition
Choose the partition type "NetBSD" for the new partition (using the "type"
option). The installation program will try to guess the "start" position based
on the end of the preceding partition. Change this value if necessary. The same
thing applies to the "size" option; the installation program will try to fill
in the space that is available until the next partition or the end of the disk
(depending on which comes first). You can change this value if it is incorrect,
or if you do not want NetBSD to use all the suggested amount of space.
After you have chosen the partition type, start position, and size, it is a
good idea to set the name that should be used in the boot menu. You can do this
by selecting the "bootmenu" option and providing a label, e.g., "NetBSD".
Repeat this step for other bootable partitions, so you can boot both NetBSD and
a Windows system (or other operating systems) using the NetBSD bootselector.
You can also choose one of the labelled partitions as default for the boot
menu. If you are satisfied with the partition options, confirm your choice by
selecting "Partition OK". Choose "Partition table OK" to leave the MBR
partition table editor.
If you have made an error in partitioning (for example you have created
overlapping partitions) sysinst will display a message and suggest to go back
to the MBR partition editor (but you are also allowed to continue). If the data
is correct but the NetBSD partition lies outside the range of sectors which is
bootable by the BIOS, sysinst will warn you and ask if you want to proceed
anyway. Doing so may lead to problems on older PCs.
Note
This is not a limitation of NetBSD. Some old BIOSes cannot boot a partition
which lies outside the first 1024 cylinders. To fully understand the problem,
you should study the different types of BIOSes and the many addressing schemes
that they use (physical CHS, logical CHS, LBA, ...). These topics are not
described in this guide.
On modern computers (those with support for int13 extensions), it is possible
to install NetBSD in partitions that live outside the first 8 GB of the hard
disk, provided that the NetBSD boot selector is installed.
Next, sysinst will offer to install a boot selector on the hard disk. This
screen is shown in Figure.10, "Installing the boot selector".
Figure.10. Énstalling the boot selector
Installing the boot selector
At this point, the BIOS partitions (called slices on BSD systems) have been
created. They are also called PC BIOS partitions, MBR partitions or fdisk
partitions.
Note
Do not confuse the slices or BIOS partitions with the BSD partitions, which are
different things.
3.6. Äisklabel partitions
Some platforms, like PC systems (amd64 and i386), use DOS-style MBR partitions
to separate file systems. The MBR partition you created earlier in the
installation process is necessary to make sure that other operating systems do
not overwrite the diskspace that you allocated to NetBSD.
NetBSD uses its own partition scheme, called a disklabel, which is stored at
the start of the MBR partition: for more information, refer to Section.2.2,
"Partitions". In the next few steps you will create a disklabel(5) and set the
sizes of the NetBSD partitions, or use existing partition sizes, as shown in
Figure.11, "Edit partitions?".
Figure.11. Ådit partitions?
Edit partitions?
When you choose to set the sizes of the NetBSD partitions you can define the
partitions you would like to create. The installation program will generate a
disklabel based on these settings. This installation screen is shown in
Figure.12, "Setting partition sizes".
Figure.12. Óetting partition sizes
Setting partition sizes
As specified in Figure.3, "The sysinst main menu", the items of the
installation menus can be selected pressing the letter displayed left of them.
Be careful that, in these menus, they do not always correspond to the BSD
disklabel partition letters. For example, third line (letter "c") of
Figure.12, "Setting partition sizes" does not refer to the whole NetBSD
partition, as well as the fourth line (letter "d") does not correspond to BSD
disklabel partition "d".
The default partition scheme of just using a big / (root) file system (plus
swap) works fine with NetBSD, and there is little need to change this.
Figure.12, "Setting partition sizes" shows how to change the size of the swap
partition to 4096 MB. Note also that partition / is marked with a "+", so it
will occupy all the remaining free space (not located for any other partition).
Changing /tmp to reside on a RAM disk (mount_tmpfs(8) or mfs(8)) for extra
speed may be a good idea. Other partition schemes may use separate partitions
for /var, /usr and/or /home, but you should use your own experience to decide
if you need this. When you completed the definition of all the desired
partitions, choose "Accept partition sizes".
The next step is to create the disklabel and edit its partitions, if necessary,
using the disklabel editor (Figure.13, "The disklabel editor"). If you
predefined the partition sizes in the previous step, the resulting disklabel
will probably fit your wishes. In that case you can complete the process
immediately by selecting "Partition sizes ok".
Figure.13. Ôhe disklabel editor
The disklabel editor
Letters in Figure.13, "The disklabel editor" are used for line selection and
to represent the corresponding BSD disklabel partitions, with the meaning
specified in Section.2.2, "Partitions". In the amd64 port, there are two
reserved partitions: "c", representing the NetBSD partition, and "d",
representing the whole disk. You can edit all the other partitions by using the
cursor keys and pressing the Return key, or using their corresponding letters.
You can add a partition by selecting an unused slot and setting parameters for
that partition. The partition editing screen is shown in Figure.14,
"Disklabel partition editing". When you are satisfied with all the values,
choose "Partition sizes ok".
Figure.14. Äisklabel partition editing
Disklabel partition editing
3.7. Óetting the disk name
After defining the partitions in the new disklabel, the last item is to enter a
name for the NetBSD disk as shown in Figure.15, "Naming the NetBSD disk".
This can be used later to distinguish between disklabels of otherwise identical
disks.
Figure.15. Îaming the NetBSD disk
Naming the NetBSD disk
3.8. Ìast chance!
The installer now has all the data it needs to prepare the disk. Nothing has
been written to the disk at this point but, and now is your last chance to
abort the installation process before actually writing data to the disk. Choose
"no" to abort the installation process and return to the main menu, or continue
by selecting "yes".
Figure.16. Ìast chance to abort
Last chance to abort
3.9. Ôhe disk preparation process
After confirming that sysinst should prepare the disk, it will run disklabel(8)
to create the NetBSD partition layout and newfs(8) to create the file systems
on the disk.
After preparing the NetBSD partitions and their filesystems, the next question
(shown in Figure.17, "Selecting bootblocks") is which bootblocks to install.
Usually you will choose the default of BIOS console, i.e., show boot messages
on your computer's display.
If you run a farm of machines without monitor, it may be more convenient to use
a serial console running on one of the serial ports. The menu also allows
changing the serial port's baud rate from the default of 9600 baud, 8 data
bits, no parity and one stopbit.
Figure.17. Óelecting bootblocks
Selecting bootblocks
3.10. Énstallation type
The installer will then ask whether you want to do a full, minimal or custom
installation. NetBSD is broken into a collection of distributions sets. "Full
installation" is the default and will install all sets; "Minimal installation"
will only install a small core set, the minimum of what is needed for a working
system. If you select "Custom installation" you can select which sets you would
like to have installed. This step is shown in Figure.18, "Full or custom
installation".
Figure.18. Æull or custom installation
Full or custom installation
If you choose to do a custom installation, sysinst will allow you to choose
which distribution sets to install, as shown in Figure.19, "Selecting
distribution sets". At a minimum, you must select a kernel and the "Base" and "
Configuration files (/etc)" sets.
Figure.19. Óelecting distribution sets
Selecting distribution sets
3.11. Ãhoosing the installation medium
At this point, you have finished the first and most difficult part of the
installation!
The second half of the installation process consists in populating the file
systems by extracting the distribution sets that you selected earlier ("Base",
"Compiler tools", "Games", etc.). Now sysinst needs to find the NetBSD sets and
you must tell it where to find them: it can be the same medium where sysinst
resides, or a different one, according to your preferences. The menu offers
several choices, as shown in Figure.20, "Installation media". The options are
explained in detail in the INSTALL documents.
Figure.20. Énstallation media
Installation media
3.11.1. Énstalling from CD-ROM / DVD / install image media
Choose this option if you want to install NetBSD from either an optic medium ("
CD-ROM / DVD") or another medium, such as an USB drive. If the running sysinst
itself has been loaded from there, the corresponding device will be
automatically selected and the extraction of the distribution sets will begin.
The CD-ROM/DVD or other device name
If sysinst is not able to detect the CD-ROM/DVD or the USB flash device, you
can gather more information about the hardware configuration as follows:
1. Press "Ctrl+Z" to pause sysinst and go to the shell prompt.
2. Type the command:
# dmesg
This will show the kernel startup messages, including information about not
detected or not configured devices. When the first CD-ROM or DVD drive in
the system is properly working, it is usually named cd0, regardless of
whether it is IDE or SCSI (or even USB or FireWire). The first USB flash
drive is named sd0 when it is correctly configured.
3. If the display scrolls too quickly, you can also use more:
# dmesg | more
4. As instructed, you can return to the NetBSD installation by typing either "
exit" or "^D" ("Ctrl+D").
3.11.2. Énstalling from an unmounted file system
Figure.21, "Mounting a file system" shows the menu to install NetBSD from an
unmounted file system. It is necessary to specify the device ("Device"), its
file system type ("File system") and a root directory inside it ("Base
directory"). The binary installation sets and the source sets are .tgz files.
The default mountpoint is "mnt" in amd64. The path is formed as follows:
/<default mountpoint>/<Base directory>/<Binary set directory> or <Source set directory>/set.tgz
Choose a combination of "Base directory" and "Binary set directory" (or "Source
set directory") that generates a valid path in your unmounted filesystem. If
more than one consecutive / appear, only the first / will actually be
considered. You need to specify a "Source set directory" only if you previously
chose to install some sources. Source sets are usually not included in the
installation images.
In the following example the install sets are stored on a MSDOS file system, on
partition "e" on the device "sd0".
Figure.21. Íounting a file system
Mounting a file system
Specify the device name and the partition. Figure.22, "Mounting a partition "
shows how to specify device "sd0" with partition "e".
Figure.22. Íounting a partition
Mounting a partition
In Figure.23, "Accessing a MSDOS file system" the file system type specified
is "msdos". This value is used to form the command mount_<File system> to mount
the volume. Any string (representing a "File system" type) which forms a valid
command is accepted: for example, the NetBSD file system "ffs" or "ext2fs", a
Linux file system. In this example, the "Base directory" item is left blank and
the binary sets are stored under /sets, so that the path becomes:
/mnt///sets
Ignoring the multiple /, this is equivalent to /mnt/sets and it is a valid one.
Choosing "Continue" will start the extraction of the sets.
Figure.23. Áccessing a MSDOS file system
Accessing a MSDOS file system
3.11.3. Énstalling via FTP and Network configuration
If you choose to install from a local network or the Internet via FTP, sysinst
must be instructed to properly get the distribution sets, as shown in
Figure.24, "Defining the FTP settings".
Figure.24. Äefining the FTP settings
Defining the FTP settings
The defaults work most of the time. You also need to configure your network
connection, before proceeding: go to the corresponding menu item, pressing
letter "j".
NetBSD currently supports installation via ethernet, USB ethernet or wireless,
and wireless LAN. Installation via DSL (PPP over Ethernet) is not supported
during installation.
In the first step, shown in Figure.25, "Which network interface to configure"
, the network card to be configured must be selected. sysinst will determine a
list of available network interfaces, present them and ask which one to use.
Figure.25. ×hich network interface to configure
Which network interface to configure
Note
The exact names of your network interfaces depend on the hardware you use.
Example interfaces are "wm" for Intel Gigabit interfaces, "ne" for NE2000 and
compatible ethernet cards, and "ath" for Atheros based wireless cards. This
list is by no means complete, and NetBSD supports many more network devices.
If your network device is not listed in Figure.25, "Which network interface
to configure", maybe it has not been properly detected. To get a list of
network interfaces available on your system, interrupt the installation process
by pressing "Ctrl+Z", then enter
# ifconfig -a
wm0: flags=0x8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
capabilities=2bf80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx>
capabilities=2bf80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Tx>
capabilities=2bf80<UDP6CSUM_Tx>
enabled=0
ec_capabilities=7<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU>
ec_enabled=0
address: 08:00:27:7e:85:d7
media: Ethernet autoselect (1000baseT full-duplex)
status: active
lo0: flags=0x8048<LOOPBACK,RUNNING,MULTICAST> mtu 33624
If the desired interface has not been shown, get more information about all the
devices found during system boot. Type:
# dmesg | more
As instructed, you can return to the NetBSD installation by typing either "exit
" or "^D" ("Ctrl+D").
Next, you have a chance to set your network medium. Press "Enter" to choose the
default.
Note
It is unlikely that you will need anything other than the default here. If you
experience problems like very slow transfers or timeouts, you may, for example,
force different duplex settings for ethernet cards. To get a list of supported
media and media options for a given network device ("wm0", for example), escape
from sysinst by pressing "Ctrl+Z", then enter:
# ifconfig -m wm0
wm0: flags=0x8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
capabilities=2bf80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx>
capabilities=2bf80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Tx>
capabilities=2bf80<UDP6CSUM_Tx>
enabled=0
ec_capabilities=7<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU>
ec_enabled=0
address: 08:00:27:7e:85:d7
media: Ethernet autoselect (1000baseT full-duplex)
status: active
supported Ethernet media:
media none
media 10baseT
media 10baseT mediaopt full-duplex
media 100baseTX
media 100baseTX mediaopt full-duplex
media autoselect
The several values printed after "media" may be of interest here, including
keywords like "autoselect" but also including any "mediaopt" settings.
Return to the installation by typing "exit" or "^D" ("Ctrl+D").
The next question, shown in Figure.26, "Using autoconfiguration", is whether
you want to perform autoconfiguration. This procedure uses DHCP (Dynamic Host
Configuration Protocol). sysinst will fetch a number of defaults from it,
giving most likely the correct settings. This procedure is recommended, unless
you want to set a static IP address, and/or specify some custom parameters.
Figure.26. Õsing autoconfiguration
Using autoconfiguration
You will then be asked for your "DNS domain"; if the machine is not in a
registered public domain, it can be left blank.
At the end of this procedure, a list of all the settings is shown, as in
Figure.27, "Confirm autoconfiguration". If they are correct, choose "Yes".
Otherwise, choosing "No", the network configuration will restart from the
beginning, giving the opportunity to perform again all the steps (and also to
perform a manual configuration).
Figure.27. Ãonfirm autoconfiguration
Confirm autoconfiguration
If you chose "No" in Figure.26, "Using autoconfiguration", you will be asked
several questions to manually configure the network. All the parameters are
presented in the form "Parameter_name [default_value]:". Press "Enter" to use
the default value. If no default value is provided, the parameter will be left
blank.
Your host name:
The name by which other machines can usually address your computer. Not
used during installation.
Your DNS Domain:
This is the name of the domain you are in. You may leave it blank if you
are not in a public domain.
Your IPv4 address:
Enter your numerical Internet Protocol address in "dotted quad" notation
here, for example, 192.168.1.3. It will be used as a static IP for your
network card.
IPv4 Netmask:
The netmask for your network, either given as a hex value ("0xffffff00") or
in dotted-quad notation ("255.255.255.0").
IPv4 gateway:
Your router's (or default gateway's) IP address. Do not use a hostname
here!
Your name server:
Your (first) DNS server's IP address. Again, don't use a hostname.
After answering all of your network configuration info, their list is shown as
in Figure.27, "Confirm autoconfiguration". You will have a chance to go back
and make changes. If you are satisfied with your settings, choose "Yes".
sysinst will now run a few commands (not displayed in detail here) to configure
the network: flushing the routing table, setting the default route, and testing
if the network connection is operational.
Now that you have a functional network connection, the menu in Figure.24,
"Defining the FTP settings" will be shown again. Choose "Get Distribution" to
continue: sysinst will download the selected set files to a temporary
directory, and then extract them.
3.11.4. Énstalling via NFS
If you want to install NetBSD from a server in your local network, NFS is an
alternative to FTP.
Note
Using this installation method requires the ability to set up an NFS server, a
topic which is not discussed here.
As shown in Figure.28, "NFS install screen", you must specify: the IP address
of the NFS server as "Host"; the directory exported by the NFS server as "Base
directory"; the directory containing the install sets as "Set directory".
Figure.28. ÎFS install screen
NFS install screen
Figure.29, "NFS example" shows an example: Host "192.168.1.50" is the NFS
server which exports the directory /home/username/Downloads. The NetBSD install
sets are stored in /home/username/Downloads/sets on the NFS server. Choose "
Continue" to start the installation of the distribution sets.
Figure.29. ÎFS example
NFS example
3.12. Åxtracting sets
After the method to obtain the distribution sets has been chosen, and (if
applicable) after those sets have been transferred, they will be extracted into
the new NetBSD file system.
A message (see Figure.30, "Extraction of sets completed") will let you know
that the set extraction is now completed and that you have the opportunity to
perform some essential configuration before finishing the NetBSD installation.
Figure.30. Åxtraction of sets completed
Extraction of sets completed
3.13. Óystem configuration
A menu with all the available configuration options is shown like in
Figure.31, "Configuration menu". After the configuration of each item, you
will get back to this menu, having the chance to select another one.
Figure.31. Ãonfiguration menu
Configuration menu
If you have not yet configured Network, you can do it now, following the same
procedure already presented in Section.11.3, "Installing via FTP and Network
configuration".
The timezone can also be configured. It is Universal Time Coordinated (UTC) by
default. Use the two-level menu of Continents/Countries and cities shown in
Figure.32, "Selecting the system's time zone" to select your local timezone
with the Return key. After a valid selection, the cursor will automatically be
moved to an "Exit" item. Then, simply press Return to exit the timezone
selection.
Figure.32. Óelecting the system's time zone
Selecting the system's time zone
The next item in Figure.31, "Configuration menu" allows you to choose which
command-line interpreter - also known as "shell" - will be used for the root
account. The default is the Bourne-compatible Almquist shell, sh(1). Other
choices are the Korn shell (ksh(1)) and the C shell (csh(1)). If, upon reading
this, you don't have some idea on which shell you prefer, simply use the
default, as this is a highly subjective decision. Should you later change your
mind, root's shell can always be changed.
Figure.33. Ãhoosing a shell
Choosing a shell
The root account still does not have a password. It is recommended to set it at
this point for security reasons, choosing the related item in Figure.31,
"Configuration menu".
Figure.34. Óet a root password?
Set a root password?
When you agree to set a root password, sysinst will run the passwd(1) utility
for you. Please note that the password is not echoed.
Figure.35. Óetting root password
Setting root password
To ease the future installation of binary packages, it is possible to make a
preliminary configuration of pkgin: choose "Enable installation of binary
packages" in Figure.31, "Configuration menu". pkgin will be fetched and
installed from an FTP server, so be sure that the network configuration has
already been done. Specify the "Host" name, its "Base directory" (where the
packages for all the NetBSD ports are stored), and the "Package directory",
related to your port and your NetBSD version. Usually, the defaults are
correct.
Figure.36. Ånabling installation of binary packages
Enabling installation of binary packages
Choosing "ftp" as "User", no password will be required. As shown in
Figure.36, "Enabling installation of binary packages", you can also choose to
install one or more additional packages, typing their names using a space as
separator, pressing "Enter" at the end. To proceed to the installation, type "x
" and press "Enter". A "pkgin update" will be run after the installation of
pkgin, to let the repository be immediately up to date.
Figure.37. Ádditional packages
Additional packages
After the procedure is completed, sysinst will show the command to install
further packages. Hit "Enter" to go back to the configuration menu.
If you need or want to build packages from their source code via pkgsrc, choose
"Fetch and unpack pkgsrc for building from source" in Figure.31,
"Configuration menu". As before, specify the "Host" name; "pkgsrc directory" is
the sources base directory. Defaults are usually the best values. A single
archive file will be downloaded, for example pkgsrc.tgz: if you want to
automatically remove it after the pkgsrc installation, move the cursor on "
Delete after install" and press "Enter". To proceed with the download, type "x"
and then press "Enter".
Figure.38. Æetch and unpack pkgsrc
Fetch and unpack pkgsrc
In the initial configuration menu (Figure.31, "Configuration menu"), it is
also possible to enable some useful services such as the daemon listening for
ssh. For information about ntpd and ntpdate, refer to Section1.2, "The
Network Time Protocol (NTP)". xdm handles the authentication and the session of
users through an X display. Usage of the Cryptographic Device Driver (cgd) is
shown in Chapter5, The cryptographic device driver (CGD). Logical Volume
Manager (lvm) is documented in Chapter8, NetBSD Logical Volume Manager (LVM)
configuration, raidframe in Chapter7, NetBSD RAIDframe. mdnsd provides a
Multicast DNS service, and also DNS Service Discovery on NetBSD: check mdnsd(8)
for more details.
Finally, the menu in Figure.31, "Configuration menu" lets you to add a
regular user to the system. For all the base information about users and root
accounts, as well as the wheel group, refer to Section.6, "Adding users".
When you completed the configuration of all the desired items, choose "Finished
configuring" in Figure.31, "Configuration menu".
3.14. Æinishing the installation
At this point the installation is finished.
Figure.39. Énstallation completed
Installation completed
After passing the dialog that confirms the installation, sysinst will return to
the main menu. Remove any installation media (CD, floppy, etc.) and choose "
Reboot the computer" to boot your new NetBSD installation.
Figure.40. Òeboot to finish installation
Reboot to finish installation
Chapter. Õpgrading NetBSD
Table of Contents
4.1. Using sysinst
4.1.1. Overview
4.1.2. The INSTALL document
4.1.3. Performing the upgrade
4.2. Using sysupgrade
This chapter describes the binary upgrade of a NetBSD system. There are a
variety of alternatives to perform this procedure, and the following sections
will guide you through them:
4.1. Õsing sysinst
4.1.1. Ïverview
To do the upgrade, you must have some form of bootable media (CD-ROM, USB
drive, floppy, etc.) available and at least the base and kern distribution
sets. Since files already installed on the system are overwritten in place, you
only need additional free space for files which weren't previously installed or
to account for growth of the sets between releases. Usually this is not more
than a few megabytes.
Note
Since upgrading involves replacing the kernel, boot blocks, and most of the
system binaries, it has the potential to cause data loss. Before beginning, you
are strongly advised to back up any important data on the NetBSD partition or
on any other partitions on your disk.
The upgrade procedure is similar to an installation, but without the hard disk
partitioning. sysinst will attempt to merge the settings stored in your /etc
directory with the new version of NetBSD. Also, file systems are checked before
unpacking the sets. Fetching the binary sets is done in the same manner as in
the installation procedure.
4.1.2. Ôhe INSTALL document
Before doing an upgrade it is essential to read the release information and
upgrading notes in one of the INSTALL files: this is the official description
of the upgrade procedure, with platform specific information and important
details. It can be found in the root directory of the NetBSD release (on the
install CD or on the FTP server).
It is advisable to print the INSTALL document out. It is available in four
formats: .txt, .ps, .more, and .html.
4.1.3. Ðerforming the upgrade
The following section provides an overview of the binary upgrade process. Most
of the following sysinst dialogs are similar to those of the installation
process. More verbose descriptions and explanations of the dialogs are
available in Chapter, Example installation.
After selecting the installation language and the keyboard type, the main menu
appears. Choosing option "b: Upgrade NetBSD on a hard disk" will start the the
upgrade process.
Figure.1. Ótarting the upgrade
Starting the upgrade
The dialog in Figure.2, "Continuing the upgrade" will request permission to
continue with the upgrade. At this point nothing has been changed yet and the
upgrade can still be cancelled. This is a good time to ask yourself whether you
have made a backup, and if you know for certain that you will be able to
restore from it.
Figure.2. Ãontinuing the upgrade
Continuing the upgrade
After choosing to continue with "Yes", the next dialog will ask you to specify
the hard disk with the NetBSD system that shall be upgraded.
Figure.3. Ãhoosing the hard drive
Choosing the hard drive
The system used for the example has only one hard disk available: "wd0".
At this point, sysinst will perform a check of the file system to ensure its
integrity.
Figure.4. Æile system check
File system check
The next step is to choose which type of bootblocks to install.
Figure.5. Ãhoosing bootblocks
Choosing bootblocks
The following dialog provides a menu to choose the installation type. The
choices are "Full installation", "Installation without X11", "Minimal
installation", or "Custom installation".
Figure.6. Ãhoosing the distribution filesets
Choosing the distribution filesets
The following dialog asks for the install method of choice and provides a list
of possible options. The install medium contains the new NetBSD distribution
sets. You will be prompted for different information depending on which option
you choose. For example, a CD-ROM or DVD install requires you to specify which
device to use and which directory the sets are in, while an FTP install
requires you to configure your network and specify the hostname of an FTP
server. More details can be found in Section.11, "Choosing the installation
medium".
Figure.7. Énstall medium
Install medium
sysinst will now unpack the distribution sets, replacing your old binaries.
After unpacking these sets, it runs the postinstall(8) script to perform
various system cleanup and configuration update tasks. If postinstall produces
errors, you will have to manually resolve the issues it brings up. See
postinstall's man page for more information. Even after a successful
postinstall run, it is advisable to use etcupdate(8) to aid in merging any
other configuration changes. You should also read the remarks in INSTALL about
upgrading, as specific compatibility issues are documented there.
Figure.8. Õpgrade complete
Upgrade complete
When you are back at the main menu, remove the boot medium (if applicable) and
reboot. Have fun with your new version of NetBSD!
4.2. Õsing sysupgrade
The sysupgrade utility (currently found in pkgsrc/sysutils/sysupgrade) allows
you to upgrade a running system to a newer binary release.
Note
upgrades across major binary releases might not work properly because of the
lack of a reboot between the kernel installation and the unpacking of the sets.
One of the benefits of sysupgrade is that it is an integrated and
almost-unattended solution: the tool fetches the new kernel and distribution
sets from remote sites if you desire and performs the upgrade without user
intervention until new changes to the configuration files need to be merged.
Let's assume you are running NetBSD/amd64 7.1 and you wish to upgrade to NetBSD
7.2. The procedure to do so would be to run the following command:
# sysupgrade auto http://cdn.NetBSD.org/pub/NetBSD/NetBSD-7.2/amd64
And that's all that it takes. This will proceed to download the kernel and sets
appropriate for your machine, unpack them and assist you in merging new
configuration changes. Do not forget to reboot afterwards.
For more details, please see the included sysupgrade(8) manual page and the /
usr/pkg/etc/sysupgrade.conf configuration file.
Part ÉII. Óystem configuration, administration and tuning
Table of Contents
5. The first steps on NetBSD
5.1. Troubleshooting
5.1.1. Boot problems
5.1.2. Misconfiguration of /etc/rc.conf
5.2. The man command
5.3. Editing configuration files
5.4. Login
5.5. Changing the root password
5.6. Adding users
5.7. Shadow passwords
5.8. Changing the keyboard layout
5.9. System time
5.10. Secure Shell (ssh(1))
5.11. Basic configuration in /etc/rc.conf
5.12. Basic network settings
5.13. Mounting a CD-ROM
5.14. Mounting a floppy
5.15. Installing additional software
5.16. Security alerts
5.17. Stopping and rebooting the system
6. Editing
6.1. Introducing vi
6.1.1. The vi interface
6.1.2. Switching to Edit Mode
6.1.3. Switching Modes & Saving Buffers to Files
6.1.4. Yanking and Putting
6.1.5. Navigation in the Buffer
6.1.6. Searching a File, the Alternate Navigational Aid
6.1.7. A Sample Session
6.2. Configuring vi
6.2.1. Extensions to .exrc
6.2.2. Documentation
6.3. Using tags with vi
7. The rc.d System
7.1. Basics
7.2. The rc.d Scripts
7.2.1. Packages installing rc.d scripts
7.3. The Role of rcorder and rc.d Scripts
7.4. Additional Reading
8. Console drivers
8.1. wscons
8.1.1. wsdisplay
8.1.2. wskbd
8.1.3. wsmouse
9. X
9.1. What is X11?
9.2. Configuration
9.3. The keyboard
9.4. The monitor
9.5. Starting X
9.6. Customizing X
9.7. Other window managers or desktop environments
9.8. Graphical login with xdm
10. Audio
10.1. Configuring the default audio device
10.2. Configuring the mixer and volume
10.2.1. Setting default mixer settings on boot
10.3. Pseudo audio devices
10.4. Recording and playback commands
10.4.1. audioplay(1)
10.4.2. audiorecord(1)
10.4.3. audioctl(1)
10.5. MIDI support
10.5.1. midirecord(1)
10.5.2. midiplay(1)
10.6. Intel HD Audio devices
10.6.1. Built-in and jacks: DACs/ADCs
10.6.2. HDMI/DisplayPort audio
11. Power management
11.1. Basic power management commands
11.1.1. Powering off or rebooting the system
11.1.2. Using ACPI sleep states (suspend and resume)
11.1.3. Suspending and resuming individual devices
11.1.4. Adjusting CPU frequency at runtime
11.1.5. Using IEEE 802.11 (Wi-Fi) power saving mode
11.2. Sensors and monitoring
11.3. An introduction to powerd
11.3.1. Example: using powerd to suspend on lid close
11.3.2. Example: reducing CPU frequency when unplugged
12. Printing
12.1. Enabling the printer daemon
12.2. Configuring /etc/printcap
12.3. Configuring Ghostscript
12.4. Printer management commands
12.5. Remote printing
13. Using removable media
13.1. Initializing and using USB flash drives
13.2. Initializing and using floppy disks
13.3. How to use a ZIP disk
13.4. Reading data CDs with NetBSD
13.5. Reading multi-session CDs with NetBSD
13.6. Allowing normal users to access CDs
13.7. Mounting an ISO image
13.8. Using video CDs with NetBSD
13.9. Using audio CDs with NetBSD
13.10. Creating an MP3 (MPEG layer 3) file from an audio CD
13.11. Using a CD-R writer with data CDs
13.12. Using a CD-R writer to create audio CDs
13.13. Creating an audio CD from MP3s
13.14. Copying an audio CD
13.15. Copying a data CD with two drives
13.16. Using CD-RW rewritables
13.17. DVD support
13.18. Creating ISO images from a CD
13.19. Getting volume information from CDs and ISO images
14. Using virtualization: QEMU and NVMM
14.1. Enabling the NetBSD Virtual Machine Monitor
14.2. Using QEMU with NVMM
14.2.1. Starting QEMU with acceleration
14.2.2. Creating a virtual disk
14.2.3. Adding entropy to the guest
14.2.4. Using networking
14.2.5. Using audio
14.2.6. Using graphics (or no graphics)
14.3. Configuring bridged networking on a NetBSD host
14.4. Notes on using NetBSD as a guest
14.4.1. Unclean VM shutdown, data recovery, and fsck
14.4.2. NetBSD VMs lacking IPv6
14.4.3. Smooth audio playback and latency in VMs
14.4.4. Changing the console resolution in an x86 VM
15. The cryptographic device driver (CGD)
15.1. Overview
15.1.1. Why use disk encryption?
15.1.2. Logical Disk Drivers
15.1.3. Availability
15.2. Components of the Crypto-Graphic Disk system
15.2.1. Kernel driver pseudo-device
15.2.2. Ciphers
15.2.3. Obsolete Ciphers
15.2.4. Verification Methods
15.3. Example: encrypting your disk
15.3.1. Preparing the disk
15.3.2. Scrubbing the disk
15.3.3. Creating the cgd
15.3.4. Modifying configuration files
15.3.5. Restoring data
15.4. Example: encrypted CDs/DVDs
15.4.1. Creating an encrypted CD/DVD
15.4.2. Using an encrypted CD/DVD
15.5. Example: encrypted iSCSI devices
15.5.1. Creating an encrypted iSCSI device
15.5.2. Device Initialisation
15.5.3. Unmounting the Encrypted Device
15.5.4. Normal Usage
15.6. Suggestions and Warnings
15.6.1. Using a random-key cgd for swap
15.6.2. Warnings
15.7. Further Reading
16. Concatenated Disk Device (CCD) configuration
16.1. Install physical media
16.2. Configure Kernel Support
16.3. Disklabel each volume member of the CCD
16.4. Configure the CCD
16.5. Initialize the CCD device
16.6. Create a 4.2BSD/UFS filesystem on the new CCD device
16.7. Mount the filesystem
17. NetBSD RAIDframe
17.1. RAIDframe Introduction
17.1.1. About RAIDframe
17.1.2. A warning about Data Integrity, Backups, and High Availability
17.1.3. Getting Help
17.2. Setup RAIDframe Support
17.2.1. Kernel Support
17.2.2. Power Redundancy and Disk Caching
17.3. Example: RAID-1 Root Disk
17.3.1. Pseudo-Process Outline
17.3.2. Hardware Review
17.3.3. Initial Install on Disk0/wd0
17.3.4. Preparing Disk1/wd1
17.3.5. Initializing the RAID Device
17.3.6. Setting up Filesystems
17.3.7. Migrating System to RAID
17.3.8. The first boot with RAID
17.3.9. Adding Disk0/wd0 to RAID
17.3.10. Testing Boot Blocks
18. NetBSD Logical Volume Manager (LVM) configuration
18.1. Anatomy of NetBSD Logical Volume Manager
18.2. Install physical media
18.3. Configure Kernel Support
18.4. Disklabel each physical volume member of the LVM
18.5. Create Physical Volumes
18.6. Create Volume Group
18.7. Create Logical Volume
18.8. Example: LVM with Volume groups located on raid1
18.8.1. Loading Device-Mapper driver
18.8.2. Preparing raid1 installation
18.8.3. Creating PV, VG on raid disk
18.8.4. Creating LV's from VG located on raid disk
18.8.5. Integration of LV's in to the system
19. Pluggable Authentication Modules (PAM)
19.1. About
19.2. Introduction
19.3. Terms and conventions
19.3.1. Definitions
19.3.2. Usage examples
19.4. PAM Essentials
19.4.1. Facilities and primitives
19.4.2. Modules
19.4.3. Chains and policies
19.4.4. Transactions
19.5. PAM Configuration
19.5.1. PAM policy files
19.5.2. Breakdown of a configuration line
19.5.3. Policies
19.6. PAM modules
19.6.1. Common Modules
19.6.2. NetBSD-specific PAM Modules
19.7. PAM Application Programming
19.8. PAM Module Programming
19.9. Sample PAM Application
19.10. Sample PAM Module
19.11. Sample PAM Conversation Function
19.12. Further Reading
20. Tuning NetBSD
20.1. Introduction
20.1.1. Overview
20.2. Tuning Considerations
20.2.1. General System Configuration
20.2.2. System Services
20.2.3. The NetBSD Kernel
20.3. Visual Monitoring Tools
20.3.1. The top Process Monitor
20.3.2. The sysstat utility
20.4. Monitoring Tools
20.4.1. fstat
20.4.2. iostat
20.4.3. ps
20.4.4. vmstat
20.5. Network Tools
20.5.1. ping
20.5.2. traceroute
20.5.3. netstat
20.5.4. tcpdump
20.6. Accounting
20.6.1. Accounting
20.6.2. Reading Accounting Information
20.6.3. How to Put Accounting to Use
20.7. Kernel Profiling
20.7.1. Getting Started
20.7.2. Interpretation of kgmon Output
20.7.3. Putting it to Use
20.7.4. Summary
20.8. System Tuning
20.8.1. Using sysctl
20.8.2. tmpfs & mfs
20.8.3. Journaling
20.8.4. LFS
20.9. Kernel Tuning
20.9.1. Preparing to Recompile a Kernel
20.9.2. Configuring the Kernel
20.9.3. Building the New Kernel
20.9.4. Shrinking the NetBSD kernel
21. NetBSD Veriexec subsystem
21.1. How it works
21.2. Signatures file
21.3. Generating fingerprints
21.4. Strict levels
21.5. Veriexec and layered file systems
21.6. Kernel configuration
22. Bluetooth on NetBSD
22.1. Introduction
22.2. Supported Hardware
22.3. System Configuration
22.4. Human Interface Devices
22.4.1. Mice
22.4.2. Keyboards
22.5. Personal Area Networking
22.5.1. Personal Area Networking User
22.6. Serial Connections
22.7. Audio
22.7.1. SCO Audio Headsets
22.7.2. SCO Audio Handsfree
22.8. Object Exchange
22.9. Troubleshooting
23. Linux emulation
23.1. Emulation setup
23.1.1. Configuring the kernel
23.1.2. Installing the Linux libraries
23.1.3. Running Linux programs
23.2. Directory structure
23.3. Using Linux browser plugins
23.4. Further reading
24. Miscellaneous operations
24.1. Installing the boot manager
24.2. Deleting the disklabel
24.3. Speaker
24.4. Forgot root password?
24.5. Password file is busy?
24.6. Adding a new hard disk
24.7. How to rebuild the devices in /dev
Chapter. Ôhe first steps on NetBSD
Table of Contents
5.1. Troubleshooting
5.1.1. Boot problems
5.1.2. Misconfiguration of /etc/rc.conf
5.2. The man command
5.3. Editing configuration files
5.4. Login
5.5. Changing the root password
5.6. Adding users
5.7. Shadow passwords
5.8. Changing the keyboard layout
5.9. System time
5.10. Secure Shell (ssh(1))
5.11. Basic configuration in /etc/rc.conf
5.12. Basic network settings
5.13. Mounting a CD-ROM
5.14. Mounting a floppy
5.15. Installing additional software
5.16. Security alerts
5.17. Stopping and rebooting the system
After installing and rebooting, the computer will boot from the hard disk. If
everything went well you'll be looking at the login prompt within a few seconds
(or minutes, depending on your hardware). The system is not yet fully
configured, but basic configuration is easy. You will see how to quickly
configure some important things, and in doing so you will learn some basics
about how the system works.
5.1. Ôroubleshooting
5.1.1. Âoot problems
If the system does not boot it could be that the boot manager was not installed
correctly or that there is a problem with the MBR (Master Boot Record). Boot
the machine from your install medium (CD, DVD, floppy, etc.) and when you see
the boot menu, select the option to drop to the boot prompt.
type "?" or "help" for help.
> ?
commands are:
boot [xdNx:][filename] [-12acdqsvxz]
(ex. "hd0a:netbsd.old -s")
ls [path]
dev xd[N[x]]:
consdev {pc|com[0123]|com[0123]kbd|auto}
modules {enabled|disabled}
load {path_to_module}
multiboot [xdNx:][filename] [<args>]
help|?
quit
> boot hd0a:netbsd
The system should now boot from the hard disk. If NetBSD boots correctly from
the hard disk, there is probably a Master Boot Record problem. You can install
the boot manager or modify its configuration with the fdisk -B command. See
Section4.1, "Installing the boot manager" for a detailed description.
5.1.2. Íisconfiguration of /etc/rc.conf
If you or the installation software haven't done any configuration of /etc/
rc.conf (sysinst normally will), the system will drop you into single user mode
and show the message
/etc/rc.conf is not configured. Multiuser boot aborted
When the system asks you to choose a shell, simply press RETURN to get to a /
bin/sh prompt. If you are asked for a terminal type, respond with vt220 (or
whatever is appropriate for your terminal type) and press RETURN. You may need
to type one of the following commands to get your delete key to work properly,
depending on your keyboard:
# stty erase '^h'
# stty erase '^?'
At this point, you need to configure at least one file in the /etc directory.
However, the root file system (/) is mounted read-only, so you will first need
to make it writable with:
# /sbin/mount -u -w /
Next, take a look at the /etc/rc.conf file. Modify it to your tastes, making
sure that you set "rc_configured=YES " so that you don't end up in this
position again. Default values for the various programs can be found in /etc/
defaults/rc.conf. More complete documentation can be found in rc.conf(5).
When you have finished, type exit at the prompt to leave the single-user shell
and continue with the multi-user boot.
5.2. Ôhe man command
If you have never used a Unix(-like) operating system before, your best friend
is now the man command, which displays a manual page. The NetBSD manual pages
are among the best and most detailed you can find, although they are very
technical.
A good manual to read after booting a new NetBSD system is afterboot(8). It
contains information about various necessary and useful configuration settings.
man name shows the man page of the "name" command and man -k name shows a list
of man pages dealing with "name" (you can also use the apropos command).
To learn the basics of the man command, type:
# man man
Manual pages contain not only information about commands but also descriptions
of some NetBSD features and structures. For example, take a look at the hier(7)
man page, which describes in detail the layout of the filesystem used by
NetBSD.
# man hier
Other similar pages are release(7) and pkgsrc(7).
# man 8 intro
Manual pages are divided in several sections, depending on what they document:
1. general commands (tools and utilities), see intro(1)
2. system calls and error numbers, see intro(2)
3. C libraries, see intro(3)
4. special files and hardware support, see intro(4)
5. file formats, see intro(5)
6. games, see intro(6)
7. miscellaneous information pages, see intro(7)
8. system maintenance and operation commands, see intro(8)
9. kernel internals, see intro(9)
A subject may appear in more than one section of the manual; to view a specific
page, supply the section number as an argument to the man command. For example,
time appears in section 1 (the time user command) and in section 3 (the time
function of the C library). To see the man page for the time C function, write:
# man 3 time
To see all the available pages:
# man -w time
# man -a time
5.3. Åditing configuration files
Other than a shell, a text editor is the most essential tool for NetBSD system
administration.
There are two provided in the base system
* ed(1), a line orientated text editor. ed is a very simplistic text editor.
It has a command mode (active when first started) and an input mode. Its
primary advantage is that it will work even without a correct terminal type
set. In an emergency, ed is worth knowing, but note that vi(1) is available
in /rescue, which brings us to...
* vi(1), a screen orientated text editor. vi is the only screen editor
available in the base install, and requires a valid terminal type to run.
Refer to Chapter, Editing to learn more about NetBSD's default editor.
Advice
Before you continue you should know or learn how to open, edit and save files
within vi. Make sure to read Chapter, Editing.
5.4. Ìogin
For the first login you will use the root user, which is the only user defined
at the end of the installation. At the password prompt type the password for
root that you set during the installation. If you didn't set a password, just
press Enter.
NetBSD/i386 (Amnesiac) (ttyE0)
login: root
password:
We recommend creating a non-root account and using su(1) for
root access.
#
5.5. Ãhanging the root password
If you did not set a password for root during the installation, you should use
the /usr/bin/passwd command to do so now.
# /usr/bin/passwd
Changing local password for root.
New password:
Retype new password:
Passwords are not displayed on the screen while you type.
Choose a password that has numbers, digits, and special characters (not space)
as well as from the upper and lower case alphabet. Do not choose any word in
any language. It is common for an intruder to use dictionary attacks.
5.6. Ádding users
For security reasons, it is bad practice to login as root during regular use
and maintenance of the system. Instead, administrators are encouraged to add a
regular user, add the user to the wheel group, then use the su(1) command when
root privileges are required. NetBSD offers the useradd(8) utility to create
user accounts. For example, to create a new user:
# useradd -m joe
The defaults for the useradd command can be changed; see the useradd(8) man
page.
User accounts that can su to root are required to be in the "wheel" group. This
can be done when the account is created by specifying a secondary group:
# useradd -m -G wheel joe
As an alternative, the usermod(8) command can be used to add a user to an
existing group:
# usermod -G wheel joe
In case you just created a user but forgot to set a password, you can still do
that later using the passwd(1) command.
# passwd joe
Note
You can edit /etc/group directly to add users to groups, but do not edit the /
etc/passwd directly; use vipw(8).
5.7. Óhadow passwords
Shadow passwords are enabled by default. What this means is that all the
passwords in /etc/passwd are simply "*"; the encrypted passwords are stored in
a file that can only be read by root, /etc/master.passwd. When you start vipw
(8) to edit the password file, the program opens a copy of /etc/master.passwd;
when you exit, vipw checks the validity of the copy, creates a new /etc/passwd
and installs the new /etc/master.passwd file. Finally, vipw launches pwd_mkdb
(8), which creates the files /etc/pwd.db and /etc/spwd.db, two databases which
are equivalent to /etc/passwd and /etc/master.passwd but faster to process.
It is very important to always use vipw and the other tools for account
administration (chfn(1), chsh(1), chpass(1), passwd(1)) and to never directly
modify /etc/master.passwd or /etc/passwd.
5.8. Ãhanging the keyboard layout
If you do not have a US layout keyboard, you will probably want to change
keymaps. For example, to use an italian keyboard, enter the following command:
# wsconsctl -k -w encoding=it
encoding -> it
To save the keyboard layout permanently, add the following line to the /etc/
wscons.conf file:
encoding it
See Section.1.2.1, "Keyboard mappings" for a list of available keymaps.
5.9. Óystem time
NetBSD, like all Unix systems, uses a system clock based on UTC (Coordinated
Universal Time) and this is what you should set your system clock to. If you
want to keep the system clock set to the local time (because, for example, you
have a dual boot system with Windows installed), you must notify NetBSD, adding
rtclocaltime=YES to /etc/rc.conf:
# echo rtclocaltime=YES >> /etc/rc.conf
# sh /etc/rc.d/rtclocaltime restart
Note
Alternatively, it is possible to configure Windows 7 and beyond to cope with
the RTC being UTC. As alluded to in this Microsoft Knowledge Base article, the
way to do this is to add a DWORD registry key named RealTimeIsUniversal, with a
value of 1, to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\
TimeZoneInformation.
The number of minutes west of GMT is calculated automatically and is set in the
kern.rtc_offset sysctl variable.
To display the current setting of the kern.rtc_offset variable:
# sysctl kern.rtc_offset
kern.rtc_offset = -60
This automatic configuration only works if you have set the proper time zone
with a symbolic link to /etc/localtime. Normally this is done as part of the
install procedure, but if for some reason it wasn't, you can set it by creating
a symbolic link from a file in the /usr/share/zoneinfo directory to /etc/
localtime.
The following example sets the time zone to Eastern Europe Summer Time:
# ln -fs /usr/share/zoneinfo/Europe/Helsinki /etc/localtime
5.10. Óecure Shell (ssh(1))
By default, all services are disabled in a fresh NetBSD installation, and ssh
(1) is no exception. You may wish to enable it so you can log in to your system
remotely. Set sshd=YES in /etc/rc.conf and then start the server with the
command
# /etc/rc.d/sshd start
The first time the server is started, it will generate a new keypair, which
will be stored inside the directory /etc/ssh.
5.11. Âasic configuration in /etc/rc.conf
NetBSD uses /etc/rc.conf to determine what will be executed when the system
boots. Understanding this file is important. The rc.conf(5) manual page
contains a detailed description of all available options.
The /etc/defaults/rc.conf file contains the default values for most settings.
To override a default value, the new value must be put into /etc/rc.conf. The
definitions there override the ones in /etc/defaults/rc.conf (which you should
leave unchanged).
# man rc.conf
The first modifications are:
* Set "rc_configured=YES" (this modification should already have been done by
the installation software.)
* Set "dhcpcd=YES" to configure your system's network using DHCP.
* Define a hostname for your machine (use a fully qualified hostname, i.e.,
one including domain). If you have a standalone machine you can use any
name (for example, vigor3.your.domain). If your machine is connected to a
network, you should supply the correct name.
* If your machine is connected to a local network or the Internet through a
router, set the defaultroute variable to the IP address of your router
(sometimes called a default gateway). For example, "defaultroute=
192.168.1.1".
5.12. Âasic network settings
To resolve the names and IP addresses of remote hosts, the system needs access
to a (remote or local) DNS nameserver. Tell the system which nameserver(s) to
use by adding the IP address of one or more nameservers to the /etc/resolv.conf
file, using the following as an example:
nameserver 145.253.2.75
To set the names of local hosts that are not available through DNS, edit the /
etc/hosts file, which has the form:
IP-address hostname host
For example:
192.168.1.3 vigor3.your.domain vigor3
5.13. Íounting a CD-ROM
New users are often surprised by the fact that although the installation
program recognized and mounted their CD-ROM perfectly, the installed system
seems to have "forgotten" how to use the CD-ROM. There is no special magic for
using a CD-ROM; you can mount it like any other file system. All you need to
know is the device name and some options to the mount(8) command. You can find
the device name with the aforementioned dmesg(8) command. For example, if dmesg
displays:
# dmesg | grep ^cd
cd0 at atapibus0 drive 1: <ASUS CD-S400/A, , V2.1H> type 5 cdrom removable
the device name is cd0, and you can mount the CD-ROM with the following
commands:
# mkdir /cdrom
# mount -t cd9660 -o ro /dev/cd0a /cdrom
To make things easier, you can add a line to the /etc/fstab file:
/dev/cd0a /cdrom cd9660 ro,noauto 0 0
Without the need to reboot, you can now mount the CD-ROM with:
# mount /cdrom
When the CD-ROM is mounted you can't eject it manually; you will have to
unmount it before you can do that:
# umount /cdrom
There is also a software command which unmounts the CD-ROM and ejects it:
# eject /dev/cd0a
5.14. Íounting a floppy
To mount a floppy you must know the name of the floppy device and the file
system type of the floppy. Read the fdc(4) manpage for more information about
device naming, as this will differ depending on the exact size and kind of your
floppy disk. For example, to read and write a floppy in MS-DOS format you use
the following command:
# mount -t msdos /dev/fd0a /mnt
Instead of /mnt, you can use another directory of your choice; you could, for
example, create a /floppy directory like you did for the CD-ROM. If you do a
lot of work with MS-DOS floppies, you will want to install the mtools package,
which enables you to access a MS-DOS floppy (or hard disk partition) without
the need to mount it. It is very handy for quickly copying a file to or from a
floppy:
# mcopy foo bar a:
# mcopy a:baz.txt baz
# mcopy a:\*.jpg .
5.15. Énstalling additional software
Using packages from pkgsrc
If you wish to install any of the software freely available for UNIX-like
systems you are strongly advised to first check the NetBSD package system,
pkgsrc. pkgsrc automatically handles any changes necessary to make the software
run on NetBSD. This includes the retrieval and installation of any other
packages on which the software may depend.
* See the list of available packages
* Precompiled binaries are available on the NetBSD FTP server for most ports.
To install them the PKG_PATH variable needs to be adjusted in the following
way (under the sh(1) shell):
# PKG_PATH="https://cdn.NetBSD.org/pub/pkgsrc/packages/NetBSD/$(uname -p)/$(uname -r | cut -d_ -f1)/All"
# export PKG_PATH
Applications can now be installed by the superuser root with the pkg_add
command:
# pkg_add -v perl
# pkg_add -v apache
# pkg_add -v firefox
The above commands will install the Perl programming language, Apache web
server, and the Firefox web browser as well as all the packages they depend
on.
It is recommended you install and use pkgin for most non-trivial binary
package management tasks, and managing upgrades. pkgin can be installed
from the post-installation configuration menu in sysinst, or afterwards
using pkg_add on a live system:
# pkg_add -v pkgin
It maintains a local database of packages that are on the remote server,
you can fetch the database with:
# pkgin update
Its usage is oriented on the package tools you have with other operating
systems. To search the package database for a word `stat`, use
# pkgin search WORD
To install a package (in this case `fscd`), just type
# pkgin install fluxbox
To upgrade installed packages:
# pkgin upgrade
You should read the manpage to know about more actions you can do with
pkgin.
All details about package management can be found in The pkgsrc guide
Storing third-party software
On many UNIX-like systems the directory structure under /usr/local is reserved
for applications and files which are independent of the system's software
management. This convention is the reason why most software developers expect
their software to be installed under /usr/local. NetBSD has no /usr/local
directory, but it can be created manually if needed. NetBSD does not care about
anything installed under /usr/local, so this task is left to you as the system
administrator.
5.16. Óecurity alerts
By the time that you have installed your system, it is quite likely that bugs
in the release have been found. All significant and easily fixed problems will
be reported at http://www.NetBSD.org/support/security/. It is recommended that
you check this page regularly.
5.17. Ótopping and rebooting the system
Use one of the following two shutdown commands to halt or reboot the system:
# shutdown -h now
# shutdown -r now
Two other commands to perform the same tasks are:
# halt
# reboot
halt, reboot and shutdown are not synonyms: the latter is more sophisticated.
On a multiuser system you should really use shutdown, which allows you to
schedule a shutdown time and notify users. It will also take care to stop
processes properly. For more information, see the shutdown(8), halt(8) and
reboot(8) manpages.
Chapter. Åditing
Table of Contents
6.1. Introducing vi
6.1.1. The vi interface
6.1.2. Switching to Edit Mode
6.1.3. Switching Modes & Saving Buffers to Files
6.1.4. Yanking and Putting
6.1.5. Navigation in the Buffer
6.1.6. Searching a File, the Alternate Navigational Aid
6.1.7. A Sample Session
6.2. Configuring vi
6.2.1. Extensions to .exrc
6.2.2. Documentation
6.3. Using tags with vi
6.1. Éntroducing vi
It is not like the vi editor needs introducing to seasoned UNIX users. The vi
editor, originally developed by Bill Joy of Sun Microsystems, is an endlessly
extensible, easy to use light ASCII editor and the bane of the newbie
existence. This section will introduce the vi editor to the newbie and perhaps
toss in a few ideas for the seasoned user as well.
The first half of this section will overview editing, saving, yanking/putting
and navigating a file within a vi session. The second half will be a step by
step sample vi session to help get started.
This is intended as a primer for using the vi editor, it is not by any means a
thorough guide. It is meant to get the first time user up and using vi with
enough skills to make changes to and create files.
6.1.1. Ôhe vi interface
Using the vi editor really is not much different than any other terminal based
software with one exception, it does not use a tab type (or curses if you will)
style interface, although many versions of vi do use curses it does not give
the same look and feel of the typical curses based interface. Instead it works
in two modes, command and edit. While this may seem strange, it is not much
different than windows based editing if you think about it. Take this as an
example, if you are using say gedit and you take the mouse, highlight some
text, select cut and then paste, the whole time you are using the mouse you are
not editing (even though you can). In vi, the same action is done by simply
deleting the whole line with dd in command mode, moving to the line you wish to
place it below and hitting p in command mode. One could almost say the analogy
is "mouse mode vs. command mode" (although they are not exactly identical,
conceptually the idea is similar).
To start up a vi session, one simply begins the way they might with any
terminal based software:
$ vi filename
One important note to remember here is that when a file is edited, it is loaded
into a memory buffer. The rest of the text will make reference to the buffer
and file in their proper context. A file only changes when the user has
committed changes with one of the write commands.
6.1.2. Ówitching to Edit Mode
The vi editor sports a range of options one can provide at start up, for the
time being we will just look at the default startup. When invoked as shown
above, the editors default startup mode is command mode, so in essence you
cannot commence to typing into the buffer. Instead you must switch out out of
command mode to enter text. The following text describes edit start modes:
a Áppend áfter ãursor.
A Áppend ôo ånd ïf ìine.
C Ãhange ôhe òest ïf ãurrent ìine.
cw Change ôhe ãurrent ÷ord.
i Énsert âefore ãursor.
I Énsert âefore æirst îon âlank ìine.
o Ïpen á ìine âelow æor énsert
O Ïpen á ìine ábove æor énsert.
6.1.3. Ówitching Modes & Saving Buffers to Files
Of course knowing the edit commands does not do much good if you can't switch
back to command mode and save a file, to switch back simply hit the ESC key. To
enter certain commands, the colon must be used. Write commands are one such set
of commands. To do this, simply enter :.
Hitting the colon then will put the user at the colon (or command if you will)
prompt at the bottom left corner of the screen. Now let us look at the save
commands:
:w Write ôhe âuffer ôo æile.
:wq ×rite ôhe âuffer ôo æile ánd ñuit.
6.1.4. Ùanking and Putting
What good is an editor if you cannot manipulate blocks of text? Of course vi
supports this feature as well and as with most of the vi commands it somewhat
intuitive. To yank a line but not delete it, simply enter yy or Y in command
mode and the current line will be copied into a buffer. To put the line
somewhere, navigate to the line above where the line is to be put and hit the p
key for the "put" command. To move a line, simply delete the whole line with
the dd command, navigate and put.
6.1.4.1. Ïops I Did Not Mean to do that!
Undo is pretty simple, u undoes the last action and U undoes the last line
deleted or changes made on the last line.
6.1.5. Îavigation in the Buffer
Most vi primers or tutorials start off with navigation, however, not unlike
most editors in order to navigate a file there must be something to navigate to
and from (hence why this column sort of went in reverse). Depending on your
flavor of vi (or if it even is vi and not say elvis, nvi or vim) you can
navigate in both edit and command mode.
For the beginner I feel that switching to command mode and then navigating is a
bit safer until one has practiced for awhile. The navigation keys for terminals
that are not recognized or do not support the use of arrow keys are the
following:
k Íoves ôhe ãursor õp ïne ìine.
j Íoves ôhe ãursor äown ïne ìine.
l Íoves ôhe ãursor òight ïne ãharacter.
h Íoves ôhe ãursor ìeft ïne ãharacter.
If the terminal is recognized and supports them, the arrow keys can be used to
navigate the buffer in command mode.
In addition to simple "one spot navigation" vi supports jumping to a line by
simply typing in the line number at the colon prompt. For example, if you
wanted to jump to line 223 the keystrokes from editor mode would look like so:
ESC
:223
6.1.6. Óearching a File, the Alternate Navigational Aid
The vi editor supports searching using regular expression syntax, however, it
is slightly different to invoke from command mode. One simply hits the / key in
command mode and enters what they are searching for, as an example let us say I
am searching for the expression foo:
/foo
That is it, to illustrate a slightly different expression, let us say I am
looking for foo bar:
/foo âar
6.1.6.1. Ádditional Navigation Commands
Searching and scrolling are not the only ways to navigate a vi buffer.
Following is a list of succinct navigation commands available for vi:
0 Íove ôo âeginning ïf ìine.
$ Íove ôo ånd ïf ìine.
b Âack õp ïne ÷ord.
w Íove æorward ïne ÷ord.
G Íove ôo ôhe âottom ïf ôhe âuffer.
H Íove ôo ôhe ôop ìine ïn ôhe ócreen.
L Íove ôo ôhe ìast ìine ïn ôhe ócreen.
M Íove ôhe ãursor ôo ôhe íiddle ïf ôhe ócreen.
N Ócan æor îext óearch íatch âut ïpposite äirection.
n Ócan æor îext óearch íatch én ôhe óame äirection.
6.1.7. Á Sample Session
Now that we have covered the basics, let us run a sample session using a couple
of the items discussed so far. First, we open an empty file into the buffer
from the command line like so:
# vi foo.txt
Next we switch to edit mode and enter two lines separated by an empty line,
remember our buffer is empty so we hit the i key to insert before cursor and
enter some text:
This is some text
there we skipped a line
~
~
~
~
Now hit the ESC key to switch back into command mode.
Now that we are in command mode, let us save the file. First, hit the : key,
the cursor should be sitting in the lower left corner right after a prompt. At
the : prompt enter w and hit the ENTER or RETURN key. The file has just been
saved. There should have been a message to that effect, some vi editors will
also tell you the name, how many lines and the size of the file as well.
It is time to navigate, the cursor should be sitting wherever it was when the
file was saved. Try using the arrow keys to move around a bit. If they do not
work (or you are just plain curious) try out the hjkl keys to see how they
work.
Finally, let us do two more things, first, navigate up to the first line and
then to the first character. Try out some of the other command mode navigation
keys on that line, hit the following keys a couple of times:
$
0
$
0
The cursor should hop to the end of line, back to the beginning and then to the
end again.
Next, search for an expression by hitting the / key and an expression like so:
/we
The cursor should jump to the first occurrence of we.
Now save the file and exit using write and quit:
:wq
6.2. Ãonfiguring vi
The standard editor supplied with NetBSD is, needless to say, vi, the most
loved and hated editor in the world. If you don't use vi, skip this section,
otherwise read it before installing other versions of vi. NetBSD's vi (nvi) was
written by Keith Bostic of UCB to have a freely redistributable version of this
editor and has many powerful extensions worth learning while being still very
compatible with the original vi. Nvi has become the standard version of vi for
BSD.
Amongst the most interesting extensions are:
* Extended regular expressions (egrep style), enabled with option extended.
* Tag stacks.
* Infinite undo (to undo, press u; to continue undoing, press .).
* Incremental search, enabled with the option searchincr.
* Left-right scrolling of lines, enabled with the option leftright; the
number of columns to scroll is defined by the sidescroll option.
* Command line history editing, enabled with the option cedit.
* Filename completion, enabled by the filec option.
* Backgrounded screens and displays.
* Split screen editing.
6.2.1. Åxtensions to .exrc
The following example shows a .exrc file with some extended options enabled.
set showmode ruler
set filec=^[
set cedit=^[
The first line enables the display of the cursor position (row and column) and
of the current mode (Command, Insert, Append) on the status line. The second
line (where ^[ is the ESC character) enables filename completion with the ESC
character. The third line enables command line history editing (also with the
ESC character.) For example, writing ":" and then pressing ESC opens a window
with a list of the previous commands which can be edited and executed (pressing
Enter on a command executes it.)
6.2.2. Äocumentation
The misc installation set (misc.tgz) contains a lot of useful documentation on
(n)vi and ex, and when installed it is available in /usr/share/doc directory.
For example:
* Edit: A tutorial - /usr/share/doc/usd/edit/edit.{ps.gz,txt}
* Ex Reference Manual - /usr/share/doc/reference/ref1/ex/reference.
{ps.gz,txt}
* Vi man page - vi(1)
* An Introduction to Display Editing with Vi by William Joy and Mark Horton -
/usr/share/doc/usd/vi/vitut.{ps.gz,txt}
* Vi/Ex Reference Manual by Keith Bostic - /usr/share/doc/reference/ref1/vi/
vi.{ps.gz,txt}
* Ex/Vi Quick Reference - /usr/share/doc/usd/vi/summary.{ps.gz,txt}
If you have never used vi, An Introduction to Display Editing with Vi by
William Joy and Mark Horton is a very good starting point.
If you want to learn more about vi and the nvi extensions you should read the
Vi/Ex Reference Manual by Keith Bostic which documents all the editor's
commands and options.
6.3. Õsing tags with vi
This topic is not directly related to NetBSD but it can be useful, for example,
for examining the kernel sources.
When you examine a set of sources in a tree of directories and subdirectories
you can simplify your work using the tag feature of vi. The method is the
following:
1. cd to the base directory of the sources.
$ cd /path
2. Write the following commands:
$ find . -name "*.[ch]" > filelist
$ cat filelist | xargs ctags
3. Add the following line to .exrc
set tags=/path/tags
(substitute the correct path instead of path.)
Chapter. Ôhe rc.d System
Table of Contents
7.1. Basics
7.2. The rc.d Scripts
7.2.1. Packages installing rc.d scripts
7.3. The Role of rcorder and rc.d Scripts
7.4. Additional Reading
NetBSD uses individual scripts for controlling services, similar to what System
V does, but without runlevels. This chapter is an overview of the rc.d system
and its configuration.
7.1. Âasics
The system startup files reside in the /etc directory. They are:
* /etc/rc
* /etc/rc.conf
* /etc/rc.d/*
* /etc/rc.local
* /etc/rc.shutdown
* /etc/rc.subr
* /etc/defaults/*
* /etc/rc.conf.d/*
First, a look at controlling and supporting scripts (also documented in rc(8)).
* After the kernel has initialized all devices at startup, it starts init(8),
which in turn runs /etc/rc.
* /etc/rc sorts the scripts in /etc/rc.d using rcorder(8) and then runs them
in that order. See the rcorder(8) man page for details of how the order of
rc.d scripts is determined.
* /etc/rc.subr contains common functions used by /etc/rc and various rc.d
scripts.
* When shutting down the system with shutdown(8), /etc/rc.shutdown is run,
which runs the scripts in /etc/rc.d in reverse order (as defined by rcorder
(8)). Note that if you shut down the system using the halt(8) command,
these scripts will not be run.
Additional scripts outside of the rc.d directory:
* /etc/rc.local is almost the last script called at boot up. This script can
be edited by the administrator to start local daemons that don't fit the
rc.d model.
rc.d scripts are controlled by a central configuration file, /etc/rc.conf,
which loads its default settings from /etc/defaults/rc.conf. If you want to
change a default setting, do not edit /etc/defaults/rc.conf; instead, override
the setting in /etc/rc.conf.
It is a good idea to read the rc.conf(5) man page to learn about the services
that are available to you.
The following example shows how to enable the SSH daemon, which is disabled by
default:
# cd /etc; grep ssh defaults/rc.conf
sshd=NO sshd_flags=""
# echo "sshd=YES" >> rc.conf
Now sshd(8) will be started automatically at system startup. The next section
describes how to start and stop services at any time.
Last but not least, files can be created in the /etc/rc.conf.d/ directory to
override the behavior of a given rc.d script without editing the script itself.
7.2. Ôhe rc.d Scripts
The actual scripts that control services are in /etc/rc.d. These scripts are
automatically run at boot time, but they can be called manually if necessary.
The following example shows how to start the SSH daemon that we enabled in the
previous section:
# /etc/rc.d/sshd start
Starting sshd.
Later, if you wish to stop the SSH daemon, run the following command:
# /etc/rc.d/sshd stop
Stopping sshd.
Waiting for PIDS: 123.
The rc.d scripts take one of the following arguments:
* start
* stop
* restart
* status
Some scripts may support other arguments (e.g., "reload"), but every script
will support at least the above commands.
As an example, after adding a new record to a named(8) database, the daemon can
be told to reload its configuration files with the following command:
# /etc/rc.d/named reload
Reloading named config files.
Note that all of the commands discussed above will only take action if the
particular service is enabled in /etc/rc.conf. It is possible to bypass this
requirement by prepending "one" to the command, as in:
# /etc/rc.d/httpd onestart
Starting httpd.
The above command will allow you to start the httpd(8) service one time. To
stop a service that has been started in this manner, pass "onestop" to the
script.
7.2.1. Ðackages installing rc.d scripts
Several packages install rc.d scripts. By default package rc.d scripts can be
found in /usr/pkg/share/examples/rc.d and need to be manually copied to /etc/
rc.d in order to be used. Setting PKG_RCD_SCRIPTS=yes environment variable
prior installing packages enable automatic copying rc.d scripts to /etc/rc.d.
7.3. Ôhe Role of rcorder and rc.d Scripts
The startup system of every Unix system determines, in one way or another, the
order in which services are started. On some Unix systems this is done by
numbering the files and/or putting them in separate run level directories.
Solaris relies on wildcards like /etc/rc[23].d/S* being sorted numerically when
expanded. Some simply put all the commands that should be started into a single
monolithic script (this is the traditional BSD method, and is what NetBSD did
before the rc.d system). On modern NetBSD this is done by the rc.d scripts and
their contents. Please note that NetBSD does not use multiple runlevels.
At the beginning of each rc.d script there is a series of commented out lines
that have one of the following items in them:
* REQUIRE
* PROVIDE
* BEFORE
* KEYWORD
These describe the dependencies of that particular script and allow rcorder to
easily work either "up" or "down" as the situation requires. As an example,
here is the ordering information contained in /etc/rc.d/nfsd:
...
PROVIDE: nfsd
REQUIRE: rpcbind mountd
...
Here we can see that this script provides the "nfsd" service and that it
requires "rpcbind" and "mountd" to be running first. The rcorder(8) utility is
used at system startup time to read through all the rc.d scripts and determine
the order in which they should be run.
7.4. Ádditional Reading
Luke Mewburn, one of the principal designers of the rc.d system, gave a
presentation on the system at USENIX 2001. It is available in PDF format.
Chapter. Ãonsole drivers
Table of Contents
8.1. wscons
8.1.1. wsdisplay
8.1.2. wskbd
8.1.3. wsmouse
8.1. ÷scons
Wscons is NetBSD's platform-independent workstation console driver. It handles
complete abstraction of keyboards and mice. This means that you can plug in
several keyboards or mice and they will be multiplexed onto a single terminal,
but also that it can multiplex several virtual terminals onto one physical
terminal.
Wscons support is enabled by default on most architectures. This can be done
manually by adding wscons=YES to your /etc/rc.conf. Then configure the desired
number of virtual consoles as described in Section.1.1.1, "Virtual consoles"
and start wscons by entering sh /etc/rc.d/wscons start followed by sh /etc/rc.d
/ttys restart. You can now switch virtual consoles by pressing Ctrl+Alt+Fn or
similar, depending on the platform.
Wscons comprises three subsystems: wsdisplay, wskbd and wsmouse. These
subsystems handle abstraction for all display, keyboard and mouse devices
respectively. The following sections discuss the configuration of wscons per
subsystem.
8.1.1. ÷sdisplay
This section will explain how to configure display and screen-related options.
8.1.1.1. Öirtual consoles
The number of pre-allocated virtual console is controlled by the following
kernel configuration option
options WSDISPLAY_DEFAULTSCREENS=4
Other consoles can be added by enabling the relevant lines in the /etc/
wscons.conf file: the comment mark (#) must be removed from the lines beginning
with screen x. In the following example a fifth console is added to the four
pre-allocated ones:
# screens to create
# idx screen emul
#screen 0 - vt100
screen 1 - vt100
screen 2 - vt100
screen 3 - vt100
screen 4 - -
#screen 4 80x25bf vt100
#screen 5 80x50 vt100
The /etc/rc.d/wscons script transforms each of the non commented lines in a
call to the wsconscfg command: the columns become the parameters of the call.
The idx column becomes the index parameter, the screen column becomes the -t
type parameter (which defines the type of screen: rows and columns, number of
colors, ...) and the emul column becomes the -e emul parameter, which defines
the emulation. For example:
screen 3 - vt100
becomes a call to:
wsconscfg -e vt100 3
Please note that it is possible to have a (harmless) conflict between the
consoles pre-allocated by the kernel and the consoles allocated at boot time
through /etc/wscons.conf. If during boot the system tries to allocate an
already allocated screen, the following message will be displayed:
wsconscfg: WSDISPLAYIO_ADDSCREEN: Device busy
The solution is to comment out the offending lines in /etc/wscons.conf.
Note that while it is possible to delete a screen and add it with different
settings, it is, technically speaking, not possible to actually modify the
settings of a screen.
screen 0 cannot be deleted if used as system console. This implies that the
setting of screen 0 cannot be changed in a running system, if used as system
console.
The virtual console must also be active in /etc/ttys, so that NetBSD runs the
getty(8) program to ask for login. For example:
console "/usr/libexec/getty Pc" pc3 off secure
ttyE0 "/usr/libexec/getty Pc" vt220 on secure
ttyE1 "/usr/libexec/getty Pc" vt220 on secure
ttyE2 "/usr/libexec/getty Pc" vt220 on secure
ttyE3 "/usr/libexec/getty Pc" vt220 off secure
...
When starting up the X server, it will look for a virtual console with no getty
(8) program running, e.g. one console should left as "off" in /etc/ttys. The
line
ttyE3 "/usr/libexec/getty Pc" vt220 off secure
of /etc/ttys is used by the X server for this purpose. To use a screen
different from number 4, a parameter of the form vtn must be passed to the X
server, where n is the number of the function key used to activate the screen
for X.
For example, screen 7 could be enabled in /etc/wscons.conf and X could be
started with vt8. If you use xdm you must edit /etc/X11/xdm/Xservers. For
example:
:0 local /usr/X11R7/bin/X +kb dpms -bpp 16 dpms vt8
8.1.1.1.1. Çetting rid of the message WSDISPLAYIO_ADDSCREEN: Device busy
This error message usually occurs when wsconscfg tries to add a screen which
already exists. This occurs if you have a screen 0 line in your /etc/
wscons.conf file, because the kernel always allocates a screen 0 as the console
device. The error message is harmless in this case, and you can get rid of it
by deleting (or commenting out) the screen 0 line.
8.1.1.2.0 lines text mode with wscons
This mode is activated in the /etc/wscons.conf. The following line must be
uncommented:
font ibm - 8 ibm /usr/share/pcvt/fonts/vt220l.808
Then the following lines must be modified:
#screen 0 80x50 vt100
screen 1 80x50 vt100
screen 2 80x50 vt100
screen 3 80x50 vt100
screen 4 80x50 vt100
screen 5 80x50 vt100
screen 6 80x50 vt100
screen 7 80x50 vt100
This configuration enables eight screens, which can be accessed with the key
combination Ctrl-Alt-Fn (where n varies from 1 to 8); the corresponding devices
are ttyE0..ttyE7. To enable them and get a login prompt, /etc/ttys must be
modified:
ttyE0 "/usr/libexec/getty Pc" vt220 on secure
ttyE1 "/usr/libexec/getty Pc" vt220 on secure
ttyE2 "/usr/libexec/getty Pc" vt220 on secure
ttyE3 "/usr/libexec/getty Pc" vt220 on secure
ttyE4 "/usr/libexec/getty Pc" vt220 on secure
ttyE5 "/usr/libexec/getty Pc" vt220 on secure
ttyE6 "/usr/libexec/getty Pc" vt220 on secure
ttyE7 "/usr/libexec/getty Pc" vt220 on secure
screen 0 as system console can be set to another screen type at boot time on
VGA displays. This is a kernel configuration option. If a non-80x25 setting is
selected, it must be made sure that a usable font is compiled into the kernel,
which would be an 8x8 one for 80x50.
There is a problem with many ATI graphics cards which don't implement the
standard VGA font switching logics: These need another kernel option to make a
nonstandard console font work.
An example set of kernel configuration options might be:
options VGA_CONSOLE_SCREENTYPE="\"80x50\""
options VGA_CONSOLE_ATI_BROKEN_FONTSEL
options FONT_VT220L8x8
8.1.1.3. Ånabling framebuffer console
On many architectures, there is only one type of screen mode: a graphical
framebuffer mode. On machines with VGA graphics cards, there is a second mode:
textmode. This is an optimized mode specially made for displaying text. Hence,
this is the default console mode for GENERIC kernels on architectures where the
graphics card is typically a VGA card (i386, amd64).
However, you can enable a framebuffer on machines with VGA cards that support
the VESA BIOS extension (VBE).
VESA framebuffer mode is configured during boot(8) using the vesa command.
8.1.1.4. Ånabling scrollback on the console
You can enable scrolling back on wscons consoles by compiling the
WSDISPLAY_SCROLLSUPPORT option into your kernel. Make sure you don't have
option VGA_RASTERCONSOLE enabled at the same time though! See Chapter4,
Compiling the kernel for instructions on building a kernel.
When you have a kernel with options WSDISPLAY_SCROLLSUPPORT running, you can
scroll up on the console by pressing LEFT SHIFT plus PAGE UP/DOWN. Please note
that this may not work on your system console (ttyE0)!
8.1.1.5. ×scons and colors
8.1.1.5.1. Ãhanging the color of kernel messages
It is possible to change the foreground and background color of kernel messages
by setting the following options in kernel config files:
options WS_KERNEL_FG=WSCOL_xxx
options WS_KERNEL_BG=WSCOL_xxx
The WSCOL_xxx color constants are defined in src/sys/dev/wscons/wsdisplayvar.h.
You can easily customize many aspects of your display appearance: the colors
used to print normal messages, the colors used to print kernel messages and the
color used to draw a border around the screen.
All of these details can be changed either from kernel options or through the
wsconsctl(8) utility; the latter may be preferable if you don't want to compile
your own kernel, as the default options in GENERIC are suitable to get this tip
working.
The following options can be set through wsconsctl(8):
* border: The color of the screen border. Its respective kernel option is
WSDISPLAY_BORDER_COLOR.
* msg.default.attrs: The attributes used to print normal console messages.
Its respective kernel options are WS_DEFAULT_COLATTR and
WS_DEFAULT_MONOATTR (the former is used in color displays, while the latter
is used in monochrome displays).
* msg.default.bg: The background color used to print normal console messages.
Its respective kernel option is WS_DEFAULT_BG.
* msg.default.fg: The foreground color used to print normal console messages.
Its respective kernel option is WS_DEFAULT_FG.
* msg.kernel.attrs: The attributes used to print kernel messages and
warnings. Its respective kernel options are WS_KERNEL_COLATTR and
WS_KERNEL_MONOATTR (the former is used in color displays, while the latter
is used in monochrome displays).
* msg.kernel.bg: The background color used to print kernel messages and
warnings. Its respective kernel option is WS_KERNEL_BG.
* msg.kernel.fg: The foreground color used to print kernel messages and
warnings. Its respective kernel option is WS_KERNEL_FG.
The values accepted as colors are: black, red, green, brown, blue, magenta,
cyan and white. The attributes are a comma separated list of one or more flags,
which can be: reverse, hilit, blink and/or underline.
For example, to emulate the look of one of those old Amstrad machines:
wsconsctl -d -w border=blue msg.default.bg=blue msg.default.fg=white msg.default.attrs=hilit
Or, to make your kernel messages appear red:
wsconsctl -d -w msg.kernel.fg=red
Note that, in older versions of NetBSD, only a subset of this functionality is
available; more specifically, you can only change the kernel colors by changing
kernel options, as explained above. Also note that not all drivers support
these features, so you may not get correct results on all architectures.
8.1.1.5.2. Çetting applications to use colors on the console
NetBSD uses the terminfo database to tell applications what the current
terminal's capabilities are. For example, some terminals don't support colors,
some don't support underlining (PC VGA terminals don't, for example) etc. The
TERM environment variable tells the terminfo library the type of terminal. It
then refers to its database for the options.
The default setting for TERM can be inspected by typing echo $TERM on the
terminal of interest. Usually this is something like vt220. This terminal type
doesn't support colors. On a typical PC console with 25 lines, you can change
this value to wsvt25 instead, to get colors. This is done in the C shell (csh)
by entering:
setenv TERM wsvt25
In a Bourne-compatible shell (sh, ksh), you can enter:
export TERM=wsvt25
If this does not work for you, you can try the ansi terminal type, which
supports ANSI color codes. However, other functionality may be missing with
this terminal type. You can have a look at the file /usr/share/misc/terminfo to
see if you can find a useful match for your console type.
8.1.1.6. Ìoading alternate fonts
There are several fonts in /usr/share/wscons/fonts that can be loaded as
console fonts. This can be done with the wsfontload(8) command, for example:
wsfontload -N ibm -h 8 -e ibm /usr/share/wscons/fonts/vt220l.808. This command
loads the IBM-encoded (-e ibm) font in the file vt2201.808 which has a height
of eight pixels (-h 8). Name it ibm for later reference (-N ibm).
To actually display the font on the console, use the command wsconsctl -dw font
=ibm.
If you want to edit a font, you can use the old pcvt utils that are available
in the sysutils/pcvt-utils package.
8.1.2. ÷skbd
8.1.2.1. Ëeyboard mappings
Wscons also allows setting the keymap to map the keys on various national
keyboards to the right characters. E.g. to set the keymap for an Italian
keymap, run:
# wsconsctl -k -w encoding=it
encoding -> it
This setting will last until the next reboot. To make it permanent, add a
encoding line to /etc/wscons.conf: it will be executed automatically the next
time you reboot.
# cp /etc/wscons.conf /etc/wscons.conf.orig
# echo encoding it >>/etc/wscons.conf
Please be careful and type two > characters. If you type only one >, you will
overwrite the file instead of adding a line. But that's why we always make
backup files before touching critical files!
A full list of keyboard mappings and variants can be found in wskbd(4).
You can change the compiled in kernel default by adding options PCKBD_LAYOUT=
KB_encoding where encoding is an uppercase entry from the list above (e.g.:
PCKBD_LAYOUT=KB_FR). Variants can be bitwise or'd in (e.g.: PCKBD_LAYOUT=KB_US|
KB_SWAPCTRLCAPS).
Configuring the keyboard layout under X is described elsewhere.
8.1.2.1.1. Èacking wscons to add a keymap
If your favourite keymap is not supported, you can start digging in src/sys/dev
/wscons/wsksymdef.h and src/sys/dev/pckbport/wskbdmap_mfii.c to make your own.
Be sure to send-pr a change-request PR with your work, so others can make use
of it!
You can test your keymap by using wsconsctl instead of directly hacking the
keymaps into the keyboard mapping file. For example, to say keycode 51 without
any modifiers should map to a comma, with shift it should map to a question
mark, with alt it should map to a semicolon and with both alt and shift it
should map to colon, issue the following command:
wsconsctl -w "map += keycode 51=comma question semicolon colon"
8.1.2.2. Ãhanging the keyboard repeat speed
Keyboard repeat speed can be tuned using the wsconsctl(8) utility. There are
two variables of interest: repeat.del1, which specifies the delay before
character repetition starts, and repeat.deln, which sets the delay between each
character repetition (once started).
Let's see an example, assuming you want to accelerate keyboard speed. You could
do, from the command line:
wsconsctl -w repeat.del1=300
wsconsctl -w repeat.deln=40
Or, if you want this to happen automatically every time you boot up the system,
you could add the following lines to /etc/wscons.conf:
setvar repeat.del1=300
setvar repeat.deln=40
8.1.3. ÷smouse
8.1.3.1. Óerial mouse support
The wsmouse device (part of wscons) does not directly support serial mice. The
moused(8) daemon is provided to read serial mouse data, convert it into wsmouse
events and inject them in wscons' event queue, so the mouse can be used through
the abstraction layer provided by wsmouse.
A typical use can be: moused -p /dev/tty00. This will try to determine the type
of mouse connected to the first serial port and start reading its data. The
moused(8) man page contains more examples.
8.1.3.2. Ãut&paste on the console with wsmoused
It is possible to use the mouse on the wscons console to mark (cut) text with
one mouse button, and insert (paste) it again with another button.
To do this, enable "wsmoused" in /etc/rc.conf, and start it:
# echo wsmoused=yes >>/etc/rc.conf
# sh /etc/rc.d/wsmoused start
After that you can use the mouse to mark text with the left mouse button, and
paste it with the right one. To tune the behaviour of wsmoused(8) see its
manpage, which also describes the format of the wsmoused.conf(5) config file,
an example of which can be found in /usr/share/examples/wsmoused.
Chapter. Ø
Table of Contents
9.1. What is X11?
9.2. Configuration
9.3. The keyboard
9.4. The monitor
9.5. Starting X
9.6. Customizing X
9.7. Other window managers or desktop environments
9.8. Graphical login with xdm
9.1. ×hat is X11?
NetBSD uses the X Window System (from X.Org) to provide a graphical interface.
Please note that the X Window System is a rather bare bones framework. It acts
as a base for modern desktop environments like MATE, or Xfce, but they are not
part of the X Window System. NetBSD ships with the X Window System, but it does
not include these desktop environments; they must be added via pkgsrc.
When you start using X you'll find many new terms which you may find confusing
at first. The basic elements are:
* An X server running on top of the hardware. The X server provides a
standard way to display graphics (including fonts for text display) and get
mouse/keyboard/other input.
* X clients. These are the programs you directly interact with. They run on
top of the X server. A web browser like Firefox is an example of an X
client. X is network-transparent, which means that you can run X clients on
one machine, and the X server (i.e., the display, with video hardware) on
another machine.
* A window manager running on top of the X server. The window manager is a
special X client that is allowed to control the placement of windows. It
can also "decorate" windows with standard "widgets" (usually these provide
actions like window motion, resizing, iconifying, window killing, etc.).
* A desktop environment such as MATE, or Xfce. These are suites of integrated
software designed to give you a well-defined range of software and a more
or less common interface to each program. These typically include a window
manager, file manager, web browser, email client, multimedia player, text
editor, address book, help browser, etc. As you may have guessed, a desktop
environment is not needed to use X, but many users will want to install
one.
The X Window System is included with NetBSD as separate distribution sets, see
Section.10, "Installation type". It can be added to an installed system with
sysinst(8).
On NetBSD, X11 lives under the filesystem hierarchy /usr/X11R7. Therefore, to
use X, /usr/X11R7/bin must be in your shell's PATH. See ~/.profile.
9.2. Ãonfiguration
In most cases, you will be able to start using X without any configuration at
all, and startx will work just fine.
In rare cases, however, configuration of the X server is required. This
configuration file is located at /etc/X11/xorg.conf. The structure of the
configuration file is described formally in xorg.conf(5).
To generate an initial configuration file for your X server, run the command
# X -configure
This command should create a configuration file and place it in your home
directory. To test the generated configuration file, run, e.g.,
# X -config ~/xorg.conf.new
If this succeeds, you should see a crosshatched background and a cursor in the
shape of an X. Try moving the cursor around to verify that the mouse is
functional. You can then switch to another virtual terminal (Ctrl-Alt-F#) or
log in remotely and kill the X process.
If the above test was successful, move the file into place as /etc/X11/
xorg.conf and you are ready to go.
9.3. Ôhe keyboard
Even if you have already configured your keyboard for wscons (see Section.1,
"wscons"), you need to configure it for X as well, at least if you want to use
a non-US layout.
An easy solution is to use setxkbmap(1) .
Here is an example that shows how to use a Hebrew keyboard, with Ctrl-Alt used
to switch layouts, and with the position of the Escape and Caps Lock keys
swapped as an additional option:
setxkbmap -option grp:alt_shift_toggle us,il \
-option caps:swapescape -option terminate:ctrl_alt_bksp
If you wish to change the repeat rate of your keyboard, you can set it with the
xset(1) command, which takes two arguments: delay and rate, respectively. The
following example sets the initial delay to 200 milliseconds and the repeat
rate to 30 per second:
$ xset r 200 30
You can also run this command in your .xinitrc or .xsession file. See below (
Section.6, "Customizing X") for more information.
9.4. Ôhe monitor
If X does not run at the resolution you think it should, first run xrandr and
see if the resolution you want is listed. If your preferred resolution is
listed in that command's output, you can change resolutions with, e.g.,
$ xrandr -s 1680x1050
xrandr can also be used to enable output to hot-plugged monitors.
Managing outputs can be done graphically with the pkgsrc package x11/arandr.
9.5. Ótarting X
You can start X with the following command:
$ startx
If your basic X server configuration is correct, you are left in the X
environment with the default window manager (ctwm). If you want a more advanced
window manager or desktop environment, many are available in pkgsrc. See
Section.7, "Other window managers or desktop environments" for information
about adding and changing window managers.
9.6. Ãustomizing X
One of the first things you will want to do is to change the programs that run
when X is first started. The easiest way to do this is to copy the default
.xinitrc file to your home directory and modify it, or create a simple new one
from scratch. For example:
$ cp /etc/X11/xinit/xinitrc ~/.xinitrc
$ vi ~/.xinitrc
If you use xdm(8), ~/.xsession is used in place of ~/.xinitrc.
The following example shows how to start the window manager (ctwm) and open an
instance of the xterm and xterm programs. The screen background color is set to
"bisque4", which is defined in /usr/X11R7/lib/X11/rgb.txt.
...
# start some programs
xclock -geometry 50x50-1-1 &
xsetroot -solid bisque4 &
xterm -geometry 80x34-1+1 -bg OldLace &
exec ctwm -W # no '&' here
With this type of setup, to quit X you must exit the window manager, which is
usually done by selecting "exit" from its menu.
The above example is very simple, but illustrates the basics of controlling the
clients that are run when X is started. You can run any number of commands from
your .xinitrc, including basic X configuration commands like xset b off to turn
off the bell.
9.7. Ïther window managers or desktop environments
If you don't like ctwm, which is a very simple window manager, you can install
another window manager or a desktop environment from pkgsrc. The following
example uses the Openbox window manager, but there are many others available in
pkgsrc/wm.
Openbox can be installed via binary packages or compiled with pkgsrc. As
always, assuming a properly set PKG_PATH, the binary package method is:
# pkg_add -v openbox
To build it with pkgsrc, run:
# cd /usr/pkgsrc/wm/openbox
# make install
Openbox is now installed; to start it you must modify your .xinitrc file:
substitute the line which calls ctwm with a line which calls openbox. For
example:
# start some useful programs
xclock -geometry 50x50-1-1 &
# start window manager:
exec openbox # no '&' here
The startx command will start the X11 session with Openbox. As configured in
the example .xinitrc file above, choosing "Log Out" from Openbox's menu will
end the X11 session.
Installing a desktop environment is almost as easy. The following example shows
how to use the Xfce desktop environment.
# pkg_add -v xfce4
Depending on your requirements, you may wish to enable dbus as a system-wide
service. The following example demonstates how. (If you don't enable dbus to
run as a system-wide service, startxfce4 will start dbus under your user
account during initialization.)
# cp /usr/pkg/share/examples/rc.d/dbus /etc/rc.d
# echo dbus=YES >> /etc/rc.conf
# /etc/rc.d/dbus start
If you wish to be able to control your system's power state from within the
desktop, the account you intend to run X under must also be a member of the "
operator" group (see Section.6, "Adding users").
After running the above commands, edit your .xinitrc as above and change "
openbox" (or "ctwm") to "startxfce4". The next time you run startx the Xfce
desktop environment will be started.
9.8. Çraphical login with xdm
If you always use X and the first thing you do after you log in is run startx,
you can set up a graphical login to do this automatically. It is very easy:
1. Create the .xsession file in your home directory. This file is similar to
.xinitrc and can, in fact, be a link to it.
$ ln -s .xinitrc ~/.xsession
2. Modify /etc/rc.conf, adding the following line:
xdm=YES # x11 display manager
3. Start xdm(8) (or reboot your system, as this will be done automatically
from now on):
# /etc/rc.d/xdm start
The configuration files for xdm are in the /etc/X11/xdm directory. The Xservers
file specifies the virtual console that X is started on. It defaults to "vt05",
which is the console you reach via "Ctrl+Alt+F5". If you want to use a
different virtual console, change vt05 as desired. In order to avoid keyboard
contention between getty and xdm, be sure to start xdm on a virtual terminal
where getty is disabled. For example, if in Xservers you have:
:0 local /usr/X11R7/bin/X :0 vt04
then in /etc/ttys you should have
ttyE3 "/usr/libexec/getty Pc" wsvt25 off secure
(Please note that vt04 corresponds to ttyE3; in /etc/X11/xdm/Xservers,
numbering starts at 1, but in /etc/ttys, numbering starts at 0).
If you want to change the look of your xdm login screen, you can modify the xdm
configuration file. For example, to change the background color you can add the
following line to the Xsetup_0 file:
xsetroot -solid SeaGreen
Chapter0. Áudio
Table of Contents
10.1. Configuring the default audio device
10.2. Configuring the mixer and volume
10.2.1. Setting default mixer settings on boot
10.3. Pseudo audio devices
10.4. Recording and playback commands
10.4.1. audioplay(1)
10.4.2. audiorecord(1)
10.4.3. audioctl(1)
10.5. MIDI support
10.5.1. midirecord(1)
10.5.2. midiplay(1)
10.6. Intel HD Audio devices
10.6.1. Built-in and jacks: DACs/ADCs
10.6.2. HDMI/DisplayPort audio
10.1. Ãonfiguring the default audio device
audiocfg(1) can be used to list, test and set default audio devices.
All available audio devices can be listed with audiocfg list:
$ audiocfg list
0: [*] audio0 @ hdafg0: Realtek ALC292
playback: 2ch, 48000Hz
record: 2ch, 48000Hz
(PR) slinear_le 16/16, 2ch, { 32000, 44100, 48000, 88200, 96000, 192000 }
(PR) slinear_le 20/32, 2ch, { 32000, 44100, 48000, 88200, 96000, 192000 }
(PR) slinear_le 24/32, 2ch, { 32000, 44100, 48000, 88200, 96000, 192000 }
( ) ac3 16/16, 2ch, { 32000, 44100, 48000, 88200, 96000, 192000 }
1: [ ] audio1 @ uaudio0: USB audio
playback: 2ch, 48000Hz
record: 1ch, 48000Hz
(P-) slinear_le 16/16, 2ch, { 48000, 44100 }
(-R) slinear_le 16/16, 1ch, { 48000, 44100 }
The asterisk next to the Realtek ALC292 device indicates it is currently the
default device, so if any application writes or reads to /dev/audio it will
play or record from it. It is also available as /dev/audio0, and for mixer
commands, /dev/mixer0.
The other device, USB audio, is a secondary device that has been plugged in.
Since it isn't the default, it is only used if specifically selected in an
application. It is available as /dev/audio1, and for mixer commands, /dev/
mixer1.
The playback: and record: rows indicate the currently selected hardware audio
format. Below this, the other supported formats are listed. Some devices set
the playback and recording formats separately, while others set both at the
same time. This is indicated by PR.
audiocfg test index can be used to test playback, and plays a tone of 2 seconds
for each channel of the index device:
$ audiocfg test 0
0: [*] audio0 @ hdafg0: Realtek ALC292
testing channel 0... done
testing channel 1... done
If more than one audio device is available, audiocfg default index can be used
to change the default one. This persists between reboots. Please note that
unlike other audiocfg(1) commands, audiocfg default needs to be run as root.
10.2. Ãonfiguring the mixer and volume
In NetBSD, mixerctl(1) is used to adjust audio mixing, e.g. volume for
recording and playback, and the sources and sinks currently in use.
Set the current playback volume:
$ mixerctl -w outputs.master=50
List the available controls and settings:
$ mixerctl -av
outputs.master=255,255 volume
inputs.dac=255,255 volume
outputs.auto=255,255 volume delta=13
outputs.headphones=0,0 volume delta=13
outputs.hdmi=255,255 volume delta=13
outputs.select=headphones [ auto headphones hdmi ]
Secondary devices can also be configured using mixerctl(1). For example, if
you've just plugged in an USB audio device, it may have attached as /dev/audio1
and /dev/mixer1 - this is visible using audiocfg(1). You would therefore
configure it with mixerctl -d /dev/mixer1.
10.2.1. Óetting default mixer settings on boot
Default mixer device settings can be applied on boot by setting mixerctl=YES in
/etc/rc.conf, then providing arguments in /etc/mixerctl.conf. For example, this
/etc/mixerctl.conf sets the playback volume and playback sink:
outputs.master=120,120
outputs.select=headphones
To automatically load and save the settings of mixer devices on boot and
shutdown, you can specify each device to save individually in /etc/rc.conf:
mixerctl=YES
mixerctl_mixers="mixer0 mixer1"
10.3. Ðseudo audio devices
NetBSD's pad(4) device allows feeding back data from an application using a
virtual audio device. It can be used to redirect playback elsewhere, or record
an application's playback.
/dev/padN devices produce a raw stream of audio in a fixed format when opened
for reading. At the time of opening, they also create a /dev/audioN device for
an application to use for output. You can observe the device creation happening
with dmesg(8).
The following example records the output of a game, games/jumpnbump, using the
program multimedia/ffmpeg4 for encoding the data from the pad device to a file
and writing it back to the real audio device simultaneously. Both are available
from the NetBSD Packages Collection.
$ ffmpeg4 -f s16le -ar 44100 -ac 2 -i /dev/pad0 \
-f wav output.wav -f oss /dev/audio
$ SDL_PATH_DSP=/dev/audio1 jumpnbump
10.4. Òecording and playback commands
NetBSD comes with a number of commands that allow users to play and record
audio from scripts or the command-line interface.
10.4.1. áudioplay(1)
With this command you can play audio files in simple formats like ULAW and
WAVE. For more sophisticated needs you might want to install one of the many
programs available in the package system which let you play audio files in
different formats (e.g. MP3, etc.)
10.4.2. áudiorecord(1)
Allows recording audio from a microphone or other input to the same simple or
raw formats that audioplay(1) supports.
The following command records CD quality audio to a WAVE file from the default
audio device. Recording will stop when the process is terminated:
$ audiorecord -d /dev/audio -F wav -e linear -c 2 -P 16 -s 44100 recording.wav
Play the recording back (its format is inferred from the WAVE headers):
$ audioplay recording.wav
10.4.3. áudioctl(1)
audioctl(1) is used to manually set some variables regarding audio I/O, like
the frequencies for playing and recording. This is useful when writing raw
samples to /dev/sound without access to the full audio(4) API, e.g. from a
shell script, but otherwise is not used during regular operation.
10.5. ÍIDI support
NetBSD includes built-in MIDI support through the machine-independent midi(4)
system. This includes support for USB MIDI devices.
Access to MIDI devices is supported through raw access to the /dev/rmidiX
devices, or through the sequencer device, /dev/music.
Digital Audio Workstations and other software with support for NetBSD MIDI in
the Packages Collection include audio/lmms and audio/fluidsynth. Several MIDI
programs are also included with NetBSD:
10.5.1. íidirecord(1)
A program that allows recording MIDI events from a device to files in the
Standard MIDI (SMF) format. It can also be used to test a device and verify it
works as expected with the -D and -V options.
10.5.2. íidiplay(1)
A program that allows playing Standard MIDI and RMID files to the MIDI
sequencer device.
10.6. Éntel HD Audio devices
Since the 2010s, most x86 machines have hardware compliant with the Intel HD
Audio specification. These use NetBSD's hdaudio(4) driver and require some
special consideration.
10.6.1. Âuilt-in and jacks: DACs/ADCs
For hdaudio(4) devices, the currently selected playback ports (or, e.g.
internal speaker and headphone jack on a laptop) are controlled by selecting a
DAC/ADC. The available DACs and ADCs can be seen in /var/run/dmesg.boot:
hdafg0 at hdaudio1: Realtek ALC292
hdafg0: DAC00 2ch: Speaker [Built-In], HP Out [Jack]
hdafg0: ADC01 2ch: Mic In [Jack]
hdafg0: ADC02 2ch: Mic In [Built-In]
Therefore, to use only the built-in mic for recording:
$ mixerctl -w record.source=ADC02
Use all available sources:
$ mixerctl -w record.source=ADC01,ADC02
Some laptops may need outputs.dacsel changed to only play audio from the
headphone jack, others have hardware speaker mute and there's no need for this.
10.6.2. ÈDMI/DisplayPort audio
Currently, HDMI/DisplayPort output with hdaudio(4) is not enabled in the
default kernel because it interferes with default device selection. This can be
changed by enabling these options in the kernel configuration, and rebuilding.
See Chapter4, Compiling the kernel for more information.
options HDAUDIO_ENABLE_DISPLAYPORT
options HDAUDIO_ENABLE_HDMI
With other drivers (e.g. on ARM boards) this is not necessary.
Chapter1. Ðower management
Table of Contents
11.1. Basic power management commands
11.1.1. Powering off or rebooting the system
11.1.2. Using ACPI sleep states (suspend and resume)
11.1.3. Suspending and resuming individual devices
11.1.4. Adjusting CPU frequency at runtime
11.1.5. Using IEEE 802.11 (Wi-Fi) power saving mode
11.2. Sensors and monitoring
11.3. An introduction to powerd
11.3.1. Example: using powerd to suspend on lid close
11.3.2. Example: reducing CPU frequency when unplugged
For power management, NetBSD supports sensor monitoring (including battery
state, CPU temperature, and so on), CPU frequency adjustment, low-power mode
for devices, hardware poweroff, and sleep (suspend-to-RAM) on some hardware.
Power management on NetBSD primarily takes the form of acpi(4) (Advanced
Configuration and Power Interface) support, although sensors are also supported
on many other types of non-ACPI hardware.
11.1. Âasic power management commands
11.1.1. Ðowering off or rebooting the system
A NetBSD system with ACPI support can be physically powered off by running the
poweroff(8) and reboot(8) commands, however, it is usually best to use shutdown
(8) so the system shuts down with appropriate warning and has time to properly
stop any running applications and services.
Shut the system down immediately:
# shutdown -p now
Reboot with a 10 minute warning to any users:
# shutdown -r +10
11.1.2. Õsing ACPI sleep states (suspend and resume)
An ACPI system is always in one of any "sleep states":
S0
fully running
S1
power on suspend (CPU and hard disks are off)
S2
similar to S3, usually not implemented
S3
suspend-to-RAM ("sleep", most of the system is inactive to save power, but
can quickly be brought back up)
S4
suspend-to-disk ("hibernate", not currently supported on NetBSD)
S5
powered off
The sleep state can be modified with sysctl(8), e.g. to suspend-to-RAM:
# sysctl -w hw.acpi.sleep.state=3
The way the system wakes up is dependent on the hardware, and may include
pressing the power button or lifting the lid. If supported, the system can
resume from a suspended state much quicker than a full reboot.
If you've tested this and verified it works as expected, you may wish to
trigger it automatically through a powerd(8) event, such as closing the lid of
a laptop.
11.1.3. Óuspending and resuming individual devices
If your machine does not support full ACPI suspend and resume, it may still be
possible to suspend and resume individual devices to save power while they are
inactive. This can be accomplished with drvctl(8).
For example, /var/run/dmesg.boot reports our hardware has a SD card reader,
rtsx0.
rtsx0 at pci1 dev 0 function 0: Realtek Semiconductor RTS5227 PCI-E Card Reader (rev. 0x01)
rtsx0: interrupting at msi4 vec 0
sdmmc0 at rtsx0
We can suspend it:
# drvctl -S rtsx0
And we can also resume it:
# drvctl -R rtsx0
If a specific device is failing to suspend or resume, this can also be used for
debugging.
11.1.4. Ádjusting CPU frequency at runtime
Many modern machines allow the CPU frequency to be dynamically adjusted. A
higher frequency provides better performance, but increased battery usage and
generates more heat. On NetBSD, CPU frequency can be adjusted at runtime with
sysctl(8).
For example, this machine is currently running at 1400 MHz, but also supports a
600 MHz low-power mode:
$ sysctl -a | grep freq
machdep.cpu.frequency.target = 1400
machdep.cpu.frequency.current = 1400
machdep.cpu.frequency.min = 600
machdep.cpu.frequency.max = 1400
machdep.cpu.frequency.available = 600 1400
We can enter the low power mode by setting the target frequency:
# sysctl -w machdep.cpu.frequency.target=600
Many modern hardware supports an "automatic adjustment" frequency, usually this
will be a reported frequency that ends in 1. On systems without this
functionality, sysutils/estd can be installed from pkgsrc to perform automatic
adjustment depending on load in software, although it will be less efficient
than hardware scaling.
11.1.5. Õsing IEEE 802.11 (Wi-Fi) power saving mode
Some IEEE 802.11 (Wi-Fi) networking devices support a low power mode, which can
be enabled with ifconfig(8):
# ifconfig iwm0 powersave
You may notice an increase in reported latency from ping(8) and a decrease in
performance. However, it may improve your device's battery life, as the radios
in such devices can consume a lot of energy. It can be disabled again with
ifconfig:
# ifconfig iwm0 -powersave
11.2. Óensors and monitoring
The primary command-line frontend to NetBSD's sensor monitoring framework is
envstat(8). Here is a typical example of envstat output:
$ envstat
Current CritMax WarnMax WarnMin CritMin Unit
[acpiacad0]
connected: FALSE
[acpibat0]
present: TRUE
design voltage: 11.100 V
voltage: 12.270 V
design cap: 23.200 Wh
last full cap: 16.940 Wh
charge: 16.770 5.000% 1.181% Wh (99.00%)
charge rate: N/A
discharge rate: N/A
charging: FALSE
charge state: NORMAL
[acpitz0]
temperature: 48.000 128.000
acpiacad0 is the machine's AC adapter. It is not currently connected.
acpibat0 is the machine's battery, currently 99% full. At 5%, a warning will be
printed to the console and an event sent to powerd(8). At 1%, the system will
shut down to prevent data loss from loss of power.
A CPU temperature sensor is also detected, acpitz0. It indicates that the CPU's
current temperature is 48 degrees Celsius, and the critical temperature is 128
degrees Celsius. If the critical temperature is reached, the system will shut
down to prevent damage to hardware. powerd(8) can be notified of changes in
temperature.
11.3. Án introduction to powerd
powerd(8) is a daemon that allows the system to respond to power management
events, such as the AC adapter being unplugged, battery state changing, a
laptop's lid being closed, or a "sleep" button being pressed.
As with other services, powerd can be enabled by editing /etc/rc.conf:
powerd=YES
And started with service(8):
# service powerd start
powerd works by executing a named sh(1) script from the directory /etc/powerd/
scripts whenever a power event occurs. We can use commands we learned in
previous sections of this chapter to our advantage in the scripts.
11.3.1. Åxample: using powerd to suspend on lid close
Example1.1.etc/powerd/scripts/lid_switch
#!/bin/sh -
#
# $NetBSD: netbsd-en.txt,v 1.71 2021/05/08 11:14:59 nia Exp $
#
# Generic script for lid switch events.
#
# Arguments passed by powerd(8):
#
# device event
case "${2}" in
pressed)
# Lock the X11 display to prevent tampering
DISPLAY=:0 /usr/pkg/bin/xlock -mode blank &
# Wait for 1 second
sleep 1
# Suspend
/sbin/sysctl -w hw.acpi.sleep.state=3
exit 0
;;
released)
exit 0
;;
*)
logger -p warning "${0}: unsupported event ${2} on device ${1}" >&1
exit 1
esac
11.3.2. Åxample: reducing CPU frequency when unplugged
Example1.2.etc/powerd/scripts/acadapter
#!/bin/sh -
#
# $NetBSD: netbsd-en.txt,v 1.71 2021/05/08 11:14:59 nia Exp $
#
# Generic script for acadapter events.
#
# Arguments passed by powerd(8):
#
# device event
case "${2}" in
pressed)
logger -p info "${0}: Full performance mode" >&1
# Disable power saving mode on all network interfaces.
for intf in $(/sbin/ifconfig -l); do
/sbin/ifconfig $intf -powersave >/dev/null 2>&1
done
# Increase CPU frequency
/sbin/sysctl -w machdep.cpu.frequency.target=2300
exit 0
;;
released)
logger -p info "${0}: Power saving mode" >&1
# Enable power saving mode on all network interfaces.
for intf in $(/sbin/ifconfig -l); do
/sbin/ifconfig $intf powersave >/dev/null 2>&1
done
# Reduce CPU frequency
/sbin/sysctl -w machdep.cpu.frequency.target=1400
exit 0
;;
*)
logger -p warning "${0}: unsupported event ${2} on device ${1}" >&1
exit 1
;;
esac
Chapter2. Ðrinting
Table of Contents
12.1. Enabling the printer daemon
12.2. Configuring /etc/printcap
12.3. Configuring Ghostscript
12.4. Printer management commands
12.5. Remote printing
This chapter describes a simple configuration for printing, using an HP Deskjet
690C printer connected to the first parallel port and the lpd printing system
that comes with NetBSD. First, the system will be configured to print text
documents, and next the configuration will be extended to print PostScript
documents using the Ghostscript program (print/ghostscript). Please note that
there are other, alternative printing systems available from the packages
collection, like LPRng (print/LPRng) and the Common Unix Printing System (CUPS)
(print/cups) which are not covered here.
12.1. Ånabling the printer daemon
After installation it is not yet possible to print, because the lpd printer
spooler daemon is not enabled. To enable lpd, one line in the /etc/rc.conf file
must be changed from:
lpd=NO
to
lpd=YES
The change will come into effect at the next boot, but the daemon can be
started manually now:
# sh /etc/rc.d/lpd start
To check if lpd is active, type the following command:
# ps ax | grep lpd
179 ?? Is 0:00.01 lpd
If you don't see an entry for lpd in the output of the previous command, the
daemon is not active.
The lpd system is configured via /etc/printcap. Before configuring /etc/
printcap it is a good idea to make a printer test, to check if the physical
connection between your computer and the printer is working. The test sends out
some data directly to the printer device. Assuming you use a printer connected
to the parallel port, this is /dev/lpt0; if you use an USB printer try /dev/
ulpt0. Please check the manpages of these devices (lpt(4), ulpt(4)) for more
information!
In our example we have a printer attached to the parallel port, so we run this:
# lptest 70 5 > /dev/lpt0
To see what the output should look like, try the same command without
redirecting the output to the printer:
# lptest 70 5
!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdef
"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefg
#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefgh
$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghi
%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghij
A frequent problem is that the output on the printer is not correctly aligned
in columns but has a "staircase" configuration. This usually means that the
printer is configured to begin a new line at the left margin after receiving
both a <CR> (carriage return, ASCII 13) character and a <LF> (line feed, ASCII
10) character. NetBSD only sends a <LF> character. You can fix this problem in
two ways:
* by changing the configuration of the printer
* by using a simple printer filter (described later)
Note
In the previous example the lpd spooler is not involved because the program
output is sent directly to the printer device (/dev/lpt0) and is not spooled.
12.2. Ãonfiguring /etc/printcap
This section explains how to configure the example printer to print text
documents.
The printer must have an entry in the /etc/printcap file; the entry contains
the printer id (the name of the printer) and the printer description. The lp id
is the default used by many programs. Here is an example entry:
Example2.1.etc/printcap
lp|local printer|HP DeskJet 690C:\
:lp=/dev/lpa0:sd=/var/spool/lpd/lp:lf=/var/log/lpd-errs:\
:sh:pl#66:pw#80:if=/usr/local/libexec/lpfilter:
The file format and options are described in detail in the printcap(5) manpage.
Please note that an input filter has been specified (with the if option) which
will take care of eliminating the staircase problem:
if=/usr/local/libexec/lpfilter
Printer driver and HP printers
Example2.1, "/etc/printcap" uses the lpa0 device (polled driver) for the
printer, instead of the lpd0 (interrupt driven driver). Using interrupts there
is a communication problem with some printers, and the HP Deskjet 690C is one
of them: printing is very slow and one PostScript page can take hours. The
problem is solved using the lpa driver. It is also possible to compile a custom
kernel where lpt is polled.
The printcap entry for the printer also specifies a spool directory, which must
be created; this directory will be used by the lpd daemon to accumulate the
data to be printed:
# cd /var/spool/lpd
# mkdir lp
# chown daemon:daemon lp
# chmod 770 lp
The only missing part is the lpfilter input filter, which must be written. The
only task performed by this filter is to configure the printer for the
elimination of the staircase problem before sending the text to be printed. The
printer used in this example requires the following initialization string: "
<ESC>&k2G".
Example2.2.usr/local/libexec/lpfilter
#!/bin/sh
# Treat LF as CR+LF
printf "\033&k2G" && cat && exit 0
exit 2
After saving this script into the name you used in /etc/printcap, you need to
make sure it's executable:
# chmod 755 /usr/local/libexec/lpfilter*
Note
There is another filter that can be used:
if=/usr/libexec/lpr/lpf:
This filter is much more complex than the one presented before. It is written
to process the output of nroff and handles underline and overprinting, expands
tab characters and converts LF to CR + LF. The source to this filter program
can be found in /usr/src/usr.sbin/lpr/filters/lpf.c.
After everything is in place now, the lptest command can be run again now, this
time using the lpr command, which will first send the data to the lpd spooler,
then runs the filter and sends the data off to the printer:
# lptest 70 5 | lpr -h
The lpr program prints text using the spooler to send data to the printer; the
-h option turns off the printing of a banner page (not really necessary,
because of the sh option in /etc/printcap). Users more familiar with the System
V printing system can also use the lp(1) command that comes as an alternative
to lpr(1).
12.3. Ãonfiguring Ghostscript
Now that basic printing works, the functionality for printing PostScript files
can be added. The simple printer used in this example does not support native
printing of PostScript files; a program must be used which is capable of
converting a PostScript document in a sequence of commands that the printer
understands. The Ghostscript program, which can be found in packages
collection, can be used to this purpose. This section explains how to configure
lpd to use Ghostscript to print PostScript files on the HP Deskjet 690C.
A second id for the printer will be created in /etc/printcap: this new id will
use a different input filter, which will call Ghostscript to perform the actual
print of the PostScript document. Therefore, text documents will be printed on
the lp printer and PostScript documents on the ps printer: both entries use the
same physical printer but have different printing filters.
The same result can be achieved using different configurations. For example, a
single entry with only one filter could be used. For this, the filter should be
able to automatically determine the format of the document being printed, and
use the appropriate printing program. This approach is simpler but leads to a
more complex filter; if you like it you should consider installing the
magicfilter program from the packages collection: it does this and many other
things automatically.
For our approach, the new /etc/printcap file looks like this:
Example2.3.etc/printcap
lp|local printer|HP DeskJet 690C:\
:lp=/dev/lpa0:sd=/var/spool/lpd/lp:lf=/var/log/lpd-errs:\
:sh:pl#66:pw#80:if=/usr/local/libexec/lpfilter:
ps|Ghostscript driver:\
:lp=/dev/lpa0:sd=/var/spool/lpd/ps:lf=/var/log/lpd-errs:\
:mx#0:sh:if=/usr/local/libexec/lpfilter-ps:
Option mx#0 is very important for printing PostScript files because it
eliminates size restrictions on the input file; PostScript documents tend to be
very big. The if option points to the new filter. There is also a new spool
directory.
The next steps are the creation of the new spool directory and of the filter
program. The procedure for the spool directory is the same as above:
# cd /var/spool/lpd
# mkdir ps
# chown daemon:daemon ps
# chmod 770 ps
The filter program for PostScript output is more complex than the text base
one: the file to be printed is fed to the interpreter which converts it into a
sequence of commands in the printer's control language, and then sends that off
to the printer. We have achieved to transform a cheap color printer in a device
suitable for PostScript output, by virtue of the NetBSD operating system and
some powerful freeware packages. The options used to configure Ghostscript are
described in the Ghostscript documentation: cdj550 is the device used to drive
the HP printer.
Example2.4.usr/local/libexec/lpfilter-ps
#!/bin/sh
# Treat LF as CR+LF
printf "\033&k2G" || exit 2
# Print the postscript file
/usr/pkg/bin/gs -dSAFER -dBATCH -dQUIET -dNOPAUSE -q -sDEVICE=cdj550 \
-sOutputFile=- -sPAPERSIZE=a4 - && exit 0
exit 2
To summarize: two different printer names have been created on the system,
which point to the same physical printer but use different options, different
filters and different spool directories. Text files and PostScript files can be
printed. To print PostScript files the Ghostscript package must be installed on
the system.
12.4. Ðrinter management commands
This section lists some useful BSD commands for printer and print jobs
administration. Besides the already mentioned lpr and lpd commands, we have:
lpq
examine the printer job queue.
lprm
delete jobs from the printer's queue.
lpc
check the printing system, enable/disable printers and printer features.
12.5. Òemote printing
It is possible to configure the printing system in order to print on a printer
connected to a remote host. Let's say that, for example, you work on the wotan
host and you want to print on the printer connected to the loge host. The /etc/
printcap file of loge is the one of Example2.3, "/etc/printcap". From wotan
it will be possible to print Postscript files using Ghostscript on loge.
The first step is to accept the print jobs submitted from the wotan host to the
loge host. To accomplish this, a line with the wotan host name must be added to
the /etc/hosts.lpd file on loge:
# hostname
loge
# cat /etc/hosts.lpd
wotan
The format of this file is very simple: each line contains the name of a host
which is permitted to print on the local system. By default the lpd daemon only
listens on UNIX domain sockets for local connections, it won't accept any
network connects. To ensure the daemon also accepts incoming network traffic,
the following will need to be added to /etc/rc.conf:
lpd_flags=""
Next, the /etc/printcap file on wotan must be configured in order to send print
jobs to loge. For example:
lp|line printer on loge:\
:lp=:sd=/var/spool/lpd/lp:lf=/var/log/lp-errs:\
:rm=loge:rp=lp
ps|Ghostscript driver on loge:\
:lp=:sd=/var/spool/lpd/ps:lf=/var/log/lp-errs:\
:mx#0:\
:rm=loge:rp=ps
There are four main differences between this configuration and the one of
Example2.3, "/etc/printcap".
1. The definition of "lp" is empty.
2. The "rm" (remote machine) entry defines the name of the host to which the
printer is connected.
3. The "rp" (remote printer) entry defines the name of the printer connected
to the remote host.
4. It is not necessary to specify input filters because the definitions on the
loge host will be used.
5. The spool directories must still be created locally on wotan:
# cd /var/spool/lpd
# mkdir lp
# chown daemon:daemon lp
# chmod 770 lp
# mkdir ps
# chown daemon:daemon ps
# chmod 770 ps
Now the print jobs for the "lp" and "ps" queues on wotan will be sent
automatically to the printer connected to loge.
Chapter3. Õsing removable media
Table of Contents
13.1. Initializing and using USB flash drives
13.2. Initializing and using floppy disks
13.3. How to use a ZIP disk
13.4. Reading data CDs with NetBSD
13.5. Reading multi-session CDs with NetBSD
13.6. Allowing normal users to access CDs
13.7. Mounting an ISO image
13.8. Using video CDs with NetBSD
13.9. Using audio CDs with NetBSD
13.10. Creating an MP3 (MPEG layer 3) file from an audio CD
13.11. Using a CD-R writer with data CDs
13.12. Using a CD-R writer to create audio CDs
13.13. Creating an audio CD from MP3s
13.14. Copying an audio CD
13.15. Copying a data CD with two drives
13.16. Using CD-RW rewritables
13.17. DVD support
13.18. Creating ISO images from a CD
13.19. Getting volume information from CDs and ISO images
13.1. Énitializing and using USB flash drives
USB flash drives can be used to share data among machines. After attaching it
we can see via dmesg(8) that it is recognised as sd0:
# dmesg
[...]
sd0 at scsibus0 target 0 lun 0: <Kingston, DataTraveler 3.0, > disk removable
sd0: fabricating a geometry
sd0: 14755 MB, 14755 cyl, 64 head, 32 sec, 512 bytes/sect x 30218842 sectors
sd0: fabricating a geometry
[...]
Warning
Please note that the following commands will erase all the previous contents on
the USB flash drive!
To initialize it we can write zeros in the first 1MB of the USB flash drive:
# dd if=/dev/zero of=/dev/rsd0d bs=1m count=1
1+0 records in
1+0 records out
1048576 bytes transferred in 0.118 secs (8886237 bytes/sec)
Via fdisk(8) we can create a partition table. MS-DOS partition and filesystem
is supported by most operating systems and devices that accept an USB disk, so
let's update the partition table (-u), creating an MS-DOS partition and set the
new partition as active (-a):
# fdisk -au sd0
fdisk: primary partition table invalid, no magic in sector 0
fdisk: Cannot determine the number of heads
Disk: /dev/rsd0d
NetBSD disklabel disk geometry:
cylinders: 14755, heads: 64, sectors/track: 32 (2048 sectors/cylinder)
total sectors: 30218842, bytes/sector: 512
BIOS disk geometry:
cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 30218842
Partitions aligned to 16065 sector boundaries, offset 63
Do you want to change our idea of what BIOS thinks? [n]
Partition table:
0: <UNUSED>
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector disabled.
No active partition.
Drive serial number: 0 (0x00000000)
Which partition do you want to change?: [none] 0
The data for partition 0 is:
<UNUSED>
sysid: [0..255 default: 169] 11
start: [0..1881cyl default: 63, 0cyl, 0MB]
size: [0..1881cyl default: 30218779, 1881cyl, 14755MB]
bootmenu: [] (space to clear)
Partition table:
0: Primary DOS with 32 bit FAT (sysid 11)
start 63, size 30218779 (14755 MB, Cyls 0-1881/9/10)
PBR is not bootable: All bytes are identical (0x00)
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector disabled.
No active partition.
Drive serial number: 0 (0x00000000)
Which partition do you want to change?: [none]
Do you want to change the active partition? [n] y
Choosing 4 will make no partition active.
active partition: [0..4 default: 4] 0
Are you happy with this choice? [n] y
We haven't written the MBR back to disk yet. This is your last chance.
Partition table:
0: Primary DOS with 32 bit FAT (sysid 11)
start 63, size 30218779 (14755 MB, Cyls 0-1881/9/10), Active
PBR is not bootable: All bytes are identical (0x00)
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector disabled.
First active partition: 0
Drive serial number: 0 (0x00000000)
Should we write new partition table? [n] y
Then we can see via disklabel(8):
# disklabel sd0
# /dev/rsd0d:
type: SCSI
disk: DataTraveler 3.0
label: fictitious
flags: removable
bytes/sector: 512
sectors/track: 32
tracks/cylinder: 64
sectors/cylinder: 2048
cylinders: 14755
total sectors: 30218842
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
5 partitions:
# size offset fstype [fsize bsize cpg/sgs]
d: 30218842 0 unused 0 0 # (Cyl. 0 - 14755*)
e: 30218779 63 MSDOS # (Cyl. 0*- 14755*)
disklabel: boot block size 0
disklabel: super block size 0
that an sd0e MSDOS partition is present.
We can finally create an MS-DOS filesystem via newfs_msdos(8):
# newfs_msdos /dev/rsd0e
/dev/rsd0e: 30189264 sectors in 1886829 FAT32 clusters (8192 bytes/cluster)
MBR type: 11
bps=512 spc=16 res=32 nft=2 mid=0xf0 spt=32 hds=64 hid=0 bsec=30218779 bspf=14741 rdcl=2 infs=1 bkbs=2
It is ready to be used and mounted via mount_msdos(8).
13.2. Énitializing and using floppy disks
PC-style floppy disks work mostly like other disk devices like hard disks,
except that you need to low-level format them first. To use an common 1440 KB
floppy in the first floppy drive, first (as root) format it:
# fdformat -f /dev/rfd0a
Then create a single partition on the disk using disklabel(8):
# disklabel -rw /dev/rfd0a floppy3
Creating a small filesystem optimized for space:
# newfs -m 0 -o space -i 16384 -c 80 /dev/rfd0a
Now the floppy disk can be mounted like any other disk. Or if you already have
a floppy disk with an MS-DOS filesystem on it that you just want to access from
NetBSD, you can just do something like this:
# mount -t msdos /dev/fd0a /mnt
However, rather than using floppies like normal (bigger) disks, it is often
more convenient to bypass the filesystem altogether and just splat an archive
of files directly to the raw device. E.g.:
# tar cvfz /dev/rfd0a file1 file2 ...
A variation of this can also be done with MS-DOS floppies using the sysutils/
mtools package which has the benefit of not going through the kernel buffer
cache and thus not being exposed to the danger of the floppy being removed
while a filesystem is mounted on it.
13.3. Èow to use a ZIP disk
1. See if your system has a ZIP drive:
# dmesg | grep -i zip
sd0 at atapibus0 drive 1: <IOMEGA ZIP 100 ATAPI, , 14.A> type 0 direct removable
Seems it has one, and it's recognized as sd0, just like any SCSI disk. The
fact that the ZIP here is an ATAPI one doesn't matter - a SCSI ZIP will
show up here, too. The ZIP is marked as "removable", which means you can
eject it with:
# eject sd0
2. Insert ZIP disk
3. Check out what partitions are on the ZIP:
# disklabel sd0
# /dev/rsd0d:
type: ATAPI
...
8 partitions:
# size offset fstype [fsize bsize cpg]
d: 196608 0 unused 0 0 # (Cyl. 0 - 95)
h: 196576 32 MSDOS # (Cyl. 0*- 95)
disklabel: boot block size 0
disklabel: super block size 0
Partition d
is the whole disk, as usual on i386.
Partition h
is what you want, and you can see it's a msdos filesystem even.
Hence, use /dev/sd0h to access the zip's partition.
4. Mount it:
# mount -t msdos /dev/sd0h /mnt
5. Access your files:
# ls -la /mnt
total 40809
drwxr-xr-x 1 root wheel 16384 Dec 31 1979 .
drwxr-xr-x 28 root wheel 1024 Aug 2 22:06 ..
-rwxr-xr-x 1 root wheel 1474560 Feb 23 1999 boot1.fs
-rwxr-xr-x 1 root wheel 1474560 Feb 23 1999 boot2.fs
-rwxr-xr-x 1 root wheel 548864 Feb 23 1999 boot3.fs
-rwxr-xr-x 1 root wheel 38271173 Feb 23 1999 netbsd19990223.tar.gz
6. Unmount the ZIP:
# umount /mnt
#
7. Eject the ZIP:
# eject sd0
#
13.4. Òeading data CDs with NetBSD
Data CDs can contain anything from programs, sound files (MP3, wav), movies
(MP3, QuickTime) to source code, text files, etc. Before accessing these files,
a CD must be mounted on a directory, much like hard disks are. Just as hard
disks can use different filesystems (ffs, lfs, ext2fs, ...), CDs have their own
filesystem, "cd9660". The NetBSD cd9660 filesystem can handle filesystems
without and with Rockridge and Joliet extensions.
CD devices are named /dev/cd0a for both SCSI and IDE (ATAPI).
With this information, we can start:
1. See if your system has some CD drive:
# dmesg | grep 'cd[0-9]*:'
cd0 at atapibus0 drive 0: <CD-R/RW RW8040A, , 1.12> type 5 cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 4, DMA mode 0
We have one drive here, "cd0". It is an IDE/ATAPI drive, as it is found on
atapibus0. Of course the drive (rather, its medium) is removable, i.e., you
can eject it. See below.
2. Insert a CD
3. Mount the CD manually:
# mount -t cd9660 /dev/cd0a /mnt
#
This command shouldn't print anything. It instructs the system to mount the
CD found on /dev/cd0a on /mnt, using the "cd9660" filesystem. The
mountpoint "/mnt" must be an existing directory.
4. Check the contents of the CD:
# ls /mnt
INSTALL.html INSTALL.ps TRANS.TBL boot.catalog
INSTALL.more INSTALL.txt binary installation
#
Everything looks fine! This is a NetBSD CD, of course. :)
5. Unmount the CD:
# umount /mnt
#
If the CD is still accessed (e.g. some other shell's still "cd"'d into it),
this will not work. If you shut down the system, the CD will be unmounted
automatically for you, there's nothing to worry about there.
6. Making an entry in /etc/fstab:
If you don't want to type the full "mount" command each time, you can put
most of the values into a line in /etc/fstab:
# Device mountpoint filesystem mount options
/dev/cd0a /cdrom cd9660 ro,noauto
Make sure that the mountpoint, /cdrom in our example, exists:
# mkdir /cdrom
#
Now you can mount the cd with the following command:
# mount /cdrom
#
Access and unmount as before.
The CD is not mounted at boot time due to the "noauto" mount option - this
is useful as you'll probably not have a CD in the drive all the time. See
mount(8) and mount_cd9660(8) for some other useful options.
7. Eject the CD:
# eject cd0
#
If the CD is still mounted, it will be unmounted if possible, before being
ejected.
13.5. Òeading multi-session CDs with NetBSD
Use mscdlabel(8) to add all sessions to the CDs disklabel, and then use the
appropriate device node to mount the session you want. You might have to create
the corresponding device nodes in /dev manually. For example:
# mscdlabel cd1
track (ctl=4) at sector 142312
adding as 'a'
track (ctl=4) at sector 0
adding as 'b'
# ls -l /dev/cd1b
ls: /dev/cd1b: No such file or directory
# cd /dev
# ls -l cd1*
brw-r----- 1 root operator 6, 8 Mar 18 21:55 cd1a
brw-r----- 1 root operator 6, 11 Mar 18 21:55 cd1d
# mknod cd1b b 6 9
to create /dev/cd1b. Make sure you fix the permissions of any new device nodes
you create:
# ls -l cd1*
brw-r----- 1 root operator 6, 8 Mar 18 21:55 cd1a
brw-r--r-- 1 root wheel 6, 9 Mar 18 22:23 cd1b
brw-r----- 1 root operator 6, 11 Mar 18 21:55 cd1d
# chgrp operator cd1b
# chmod 640 cd1b
# ls -l cd1*
brw-r----- 1 root operator 6, 8 Mar 18 21:55 cd1a
brw-r----- 1 root operator 6, 9 Mar 18 22:24 cd1b
brw-r----- 1 root operator 6, 11 Mar 18 21:55 cd1d
Now you should be able to mount it.
# mount /dev/cd1b /mnt
13.6. Állowing normal users to access CDs
By default, NetBSD only allows "root" to mount a filesystem. If you want any
user to be able to do this, perform the following steps:
* Give groups and other the access rights to the device.
# chmod go+rw /dev/cd0a
* Ask NetBSD to let users mounting filesystems.
# sysctl -w vfs.generic.usermount=1
Note that this works for any filesystem and device, not only for CDs with a
ISO 9660 filesystem.
To perform the mount operation after these commands, the user must own the
mount point. So, for example:
$ cd $HOME
$ mkdir cdrom
$ mount -t cd9660 -o nodev,nosuid /dev/cd0a `pwd`/cdrom
Please also see mount(8) and as an alternative the auto mount daemon amd(8),
for which example config files can be found in /usr/share/examples/amd.
13.7. Íounting an ISO image
Sometimes, it is interesting to mount an ISO9660 image file before you burn the
CD; this way, you can examine its contents or even copy files to the outside.
If you are a Linux user, you should know that this is done with the special
loop filesystem. NetBSD does it another way, using the vnode pseudo-disk.
We will illustrate how to do this with an example. Suppose you have an ISO
image in your home directory, called "mycd.iso":
1. Start by setting up a new vnode, "pointing" to the ISO file:
# vnconfig -c vnd0 ~/mycd.iso
2. Now, mount the vnode:
# mount -t cd9660 /dev/vnd0a /mnt
3. Yeah, image contents appear under /mnt! Go to that directory and explore
the image.
4. When you are happy, you have to umount the image:
# umount /mnt
5. And at last, deconfigure the vnode:
# vnconfig -u vnd0
Note that these steps can also be used for any kind of file that contains a
filesystem, not just ISO images.
See the vnd(4) and vnconfig(8) man pages for more information.
13.8. Õsing video CDs with NetBSD
To play MPEG Video streams as many DVD players can play them under NetBSD,
mount the CD as you would do with any normal (data) CD (see Section3.4,
"Reading data CDs with NetBSD"), then use the multimedia/xine-ui, multimedia/
mplayer or multimedia/gmplayer package to play the mpeg files stored on the CD.
13.9. Õsing audio CDs with NetBSD
There are two ways to handle audio CDs:
1. Tell the CD drive to play to the headphone or to a soundcard, to which
CDROMs are usually connected internally. Use programs like cdplay(1), audio
/xmcd, "kscd" from the multimedia/kdemultimedia3 package, mixer programs
like mixerctl(1), audio/xmix, audio/xmmix, the Curses based audio/cam, or
kmix, which is part of multimedia/kdemultimedia3.
This usually works well on both SCSI and IDE (ATAPI) CDROMs, CDRW and DVD
drives.
2. To read ("rip") audio tracks in binary form without going through digital->
analog conversion and back. There are several programs available to do
this:
+ For most ATAPI, SCSI and several proprietary CDROM drives, the audio/
cdparanoia package can be used. With cdparanoia the data can be saved
to a file or directed to standard output in WAV, AIFF, AIFF-C or raw
format. Currently the -g option is required by the NetBSD version of
cdparanoia. A hypothetical example of how to save track 2 as a WAV file
is as follows:
$ cdparanoia -g /dev/rcd0d 2 track-02.wav
If you want to grab all files from a CD, cdparanoia's batch mode is
useful:
$ cdparanoia -g /dev/rcd0d -B
+ For ATAPI or SCSI CD-ROMs the audio/cdd package can be used. To extract
track 2 with cdd, type:
# cdd -t 2 `pwd`
This will put a file called track-02.cda in the current directory.
+ For SCSI CD-ROMS the audio/tosha package can be used. To extract track
2 with tosha, you should be able to type:
# tosha -d CD-ROM-device -t 2 -o track-02.cda
The data can then be post-processed e.g. by encoding it into MP3 streams
(see Section3.10, "Creating an MP3 (MPEG layer 3) file from an audio CD")
or by writing them to CD-Rs (see Section3.12, "Using a CD-R writer to
create audio CDs").
+ To streamline the process, from obtaining audio to populating the
metadata for a track to normalising audio and such, the audio/abcde
package can be used.
# abcde -d /dev/rcd0d -o mp3 -p -P
This will encode the disc track-by-track padding the tracknumbers with
a leading 0 and using UNIX pipes to read+encode without leaving the WAV
files
13.10. Ãreating an MP3 (MPEG layer 3) file from an audio CD
The basic steps in creating an MPEG layer 3 (MP3) file from an audio CD (using
software from the NetBSD packages collection) are:
1. Extract (rip) the audio data of the CD as shown in Section3.9, "Using
audio CDs with NetBSD".
2. Convert the CD audio format file to WAV format. You only need to perform
this job if your ripping program (e.g. tosha, cdd) didn't already do the
job for you!
+ Using the audio/sox package, type:
$ sox -s -w -c 2 -r 44100 -t cdr track-02.cda track-02.wav
This will convert track-02.cda in raw CD format to track-02.wav in WAV
format, using signed 16-bit words with 2 channels at a sampling rate of
44100kHz.
3. Encode the WAV file into MP3 format.
+ Using the audio/bladeenc package, type:
$ bladeenc -128 -QUIT track-02.wav
This will encode track-02.wav into track-02.mp3 in MP3 format, using a
bit rate if 128kBit/sec. The documentation for bladeenc describes
bit-rates in more detail.
+ Using the audio/lame package, type:
$ lame -p -o -v -V 5 -h track-02.wav track-02.mp3
You may wish to use a lower quality, depending on your taste and
hardware.
The resultant MP3 file can be played with any of the audio/gqmpeg, audio/maplay
, audio/mpg123 or audio/splay packages.
13.11. Õsing a CD-R writer with data CDs
The process of writing a CD consists of two steps: First, a "image" of the data
must be generated, which can then be written to CD-R in a second step.
1. Reading a pre-existing ISO image
# dd if=/dev/rcd0a of=filename.iso bs=2k
#
Alternatively, you can create a new ISO image yourself:
2. Generating the ISO image
Put all the data you want to put on CD into one directory. Next you need to
generate a disk-like ISO image of your data. The image stores the data in
the same form as they're later put on CD, using the ISO 9660 format. The
basic ISO9660 format only understands 8+3 filenames (max. eight letters for
filename, plus three more for an extension). As this is not practical for
Unix filenames, a so-called "Rockridge Extension" needs to be employed to
get longer filenames. (A different set of such extension exists in the
Microsoft world, to get their long filenames right; that's what's known as
Joliet filesystem).
The ISO image is created using the mkisofs command, which is part of the
sysutils/cdrtools package.
Example: if you have your data in /usr/tmp/data, you can generate a ISO
image file in /usr/tmp/data.iso with the following command:
$ cd /usr/tmp
$ mkisofs -o data.iso -r data
Using NETBS000.GZ;1 for data/binary/kernel/netbsd.INSTALL.gz (netbsd.INSTALL_TINY.gz)
Using NETBS001.GZ;1 for data/binary/kernel/netbsd.GENERIC.gz (netbsd.GENERIC_TINY.gz)
5.92% done, estimate finish Wed Sep 13 21:28:11 2000
11.83% done, estimate finish Wed Sep 13 21:28:03 2000
17.74% done, estimate finish Wed Sep 13 21:28:00 2000
23.64% done, estimate finish Wed Sep 13 21:28:03 2000
...
88.64% done, estimate finish Wed Sep 13 21:27:55 2000
94.53% done, estimate finish Wed Sep 13 21:27:55 2000
Total translation table size: 0
Total rockridge attributes bytes: 5395
Total directory bytes: 16384
Path table size(bytes): 110
Max brk space used 153c4
84625 extents written (165 Mb)
$
Please see the mkisofs(8) man page for other options like noting publisher
and preparer. The Bootable CD ROM How-To explains how to generate a
bootable CD.
3. Writing the ISO image to CD-R
When you have the ISO image file, you just need to write it on a CD. This
is done with the "cdrecord" command from the sysutils/cdrtools package.
Insert a blank CD-R, and off we go:
# cdrecord -v dev=/dev/rcd0d data.iso
...
#
After starting the command, 'cdrecord' shows you a lot of information about
your drive, the disk and the image you're about to write. It then does a 10
seconds countdown, which is your last chance to stop things - type ^C if
you want to abort. If you don't abort, the process will write the whole
image to the CD and return with a shell prompt.
Note that cdrecord(8) works on both SCSI and IDE (ATAPI) drives.
4. Test
Mount the just-written CD and test it as you would do with any "normal" CD,
see Section3.4, "Reading data CDs with NetBSD".
13.12. Õsing a CD-R writer to create audio CDs
If you want to make a backup copy of one of your audio CDs, you can do so by
extracting ("ripping") the audio tracks from the CD, and then writing them back
to a blank CD. Of course this also works fine if you only extract single tracks
from various CDs, creating your very own mix CD!
The steps involved are:
1. Extract ("rip") the audio tracks as described as in Section3.9, "Using
audio CDs with NetBSD" to get a couple of .wav files.
2. Write the .wav files using cdrecord command from the sysutils/cdrtools
package:
# cdrecord -v dev=/dev/rcd0d -audio -pad *.wav
13.13. Ãreating an audio CD from MP3s
If you have converted all your audio CDs to MP3 and now want to make a mixed CD
for your (e.g.) your car, you can do so by first converting the .mp3 files back
to .wav format, then write them as a normal audio CD.
The steps involved here are:
1. Create .wav files from your .mp3 files:
$ mpg123 -w foo.wav foo.mp3
Do this for all of the MP3 files that you want to have on your audio CD.
The .wav filenames you use don't matter.
2. Write the .wav files to CD as described under Section3.12, "Using a CD-R
writer to create audio CDs".
13.14. Ãopying an audio CD
To copy an audio CD while not introducing any pauses as mandated by the CDDA
standard, you can use cdrdao for that:
# cdrdao read-cd --device /dev/rcd0d data.toc
# cdrdao write --device /dev/rcd1d data.toc
13.15. Ãopying a data CD with two drives
If you have both a CD-R and a CD-ROM drive in your machine, you can copy a data
CD with the following command:
# cdrecord dev=/dev/rcd1d /dev/rcd0d
Here the CD-ROM (cd0) contains the CD you want to copy, and the CD-R (cd1)
contains the blank disk. Note that this only works with computer disks that
contain some sort of data, it does not work with audio CDs! In practice you'll
also want to add something like "speed=8" to make things a bit faster.
13.16. Õsing CD-RW rewritables
You can treat a CD-RW drive like a CD-R drive (see Section3.11, "Using a CD-R
writer with data CDs") in NetBSD, creating images with mkisofs(8) and writing
them on a CD-RW medium with cdrecord(8).
If you want to blank a CD-RW, you can do this with cdrecord's "blank" option:
# cdrecord dev=/dev/rcd0d blank=fast
There are several other ways to blank the CD-RW, call cdrecord(8) with "blank=
help" for a list. See the cdrecord(8) man page for more information.
13.17. ÄVD support
Currently, NetBSD supports ISO 9660 and UDF DVD media. Information about
mounting ISO 9660 and UDF filesystems can be found in the mount_cd9660(8) and
mount_udf(8) manual pages respectively. DVDs, DivX and many avi files be played
with multimedia/ogle or multimedia/gmplayer.
For some hints on creating DVDs, see this postings about growisofs and this
article about recording CDs and DVDs with NetBSD.
13.18. Ãreating ISO images from a CD
To create an ISO image and save the checksum do this:
# readcd dev=/dev/cd0d f=/tmp/cd.iso
Here is an alternative using dd(1):
# dd if=/dev/cd0d of=/tmp/cd.iso bs=2048
If the CD has errors you can recover the rest with this:
# dd if=/dev/cd0d of=/tmp/cd.iso bs=2048 conv=noerror
To create an ISO image from a mounted data CD first, mount the CD disk by:
# mount -t cd9660 -r /dev/cd0d /mnt/cdrom
Second, get the image:
# mkhybrid -v -l -J -R -o /tmp/my_cd.iso /mnt/cdrom/
13.19. Çetting volume information from CDs and ISO images
You can read the volume data from an unmounted CD with this command:
# file -s /dev/cd0d
You can read the volume data from an ISO image with this command:
# isoinfo -d -i /tmp/my_cd.iso
You can get the unique disk number from an unmounted CD with this:
# cd-discid /dev/cd0d
You can read the table of contents of an unmounted CD with this command:
# cdrecord -v dev=/dev/cd0d -toc
Chapter4. Õsing virtualization: QEMU and NVMM
Table of Contents
14.1. Enabling the NetBSD Virtual Machine Monitor
14.2. Using QEMU with NVMM
14.2.1. Starting QEMU with acceleration
14.2.2. Creating a virtual disk
14.2.3. Adding entropy to the guest
14.2.4. Using networking
14.2.5. Using audio
14.2.6. Using graphics (or no graphics)
14.3. Configuring bridged networking on a NetBSD host
14.4. Notes on using NetBSD as a guest
14.4.1. Unclean VM shutdown, data recovery, and fsck
14.4.2. NetBSD VMs lacking IPv6
14.4.3. Smooth audio playback and latency in VMs
14.4.4. Changing the console resolution in an x86 VM
A virtual machine is a virtual computer (the "guest") running inside another
computer (the "host"). Virtual machines are useful for testing, running
different operating systems, isolating parts of a system, and more.
nvmm(4) (NetBSD Virtual Machine Monitor) is NetBSD's native hypervisor. In
regular usage, it's used as an "accelerator" for the QEMU virtual machine
software. It will make virtual machines on your NetBSD host run faster by
taking advantage of CPU virtualization extensions. Currently, a CPU that
supports AMD SVM or Intel VMX is required, but more backends for other
architectures may be added in the future. QEMU can also be used without an
accelerator, with significantly reduced performance.
Other hypervisors supported by NetBSD include Intel HAXM (also used with QEMU),
and Xen, which has quite a different design.
When running modern operating systems as VM guests, you will generally want to
use para-virtualized I/O, rather than having QEMU emulate real hardware
devices. On NetBSD, this is supported with the virtio(4) drivers.
14.1. Ånabling the NetBSD Virtual Machine Monitor
The NetBSD Virtual Machine Monitor isn't active by default. It must be
activated by loading the nvmm module with modload(8):
# modload nvmm
Verify NVMM is loaded with modstat(8):
# modstat | grep nvmm
nvmm misc filesys - 0 - -
You can load the module automatically at boot time by adding this line to /etc/
modules.conf:
nvmm
Loading NVMM at boot time will also allow the system to run with a
secmodel_securelevel(9) of 1, which prevents loading modules after boot.
However, since NVMM blocks things like suspend, you may wish to unload it:
# modunload nvmm
By default the /dev/nvmm device is owned by the root user. You probably want to
run virtual machines as a non-root user for security reasons, so set the owner
of the /dev/nvmm device to something reasonable:
# chown nia:wheel /dev/nvmm
On a machine containing lots of untrusted VMs, you may wish to create a
dedicated user or group for them with useradd(8) and groupadd(8).
You can see NVMM's current status with nvmmctl(8):
$ nvmmctl identify
nvmm: Kernel API version 2
nvmm: State size 1008
nvmm: Max machines 128
nvmm: Max VCPUs per machine 256
nvmm: Max RAM per machine 128G
nvmm: Arch Mach conf 0
nvmm: Arch VCPU conf 0x3<CPUID,TPR>
nvmm: Guest FPU states 0x3<x87,SSE>
14.2. Õsing QEMU with NVMM
QEMU is a CPU emulator and virtual machine that can use NVMM as an accelerator.
It isn't included with NetBSD by default. However, it is available in pkgsrc as
emulators/qemu, and can be installed with pkgin:
# pkgin install qemu
14.2.1. Ótarting QEMU with acceleration
This command starts a VM in an X11 window with NVMM acceleration, the same CPU
type as the host machine, two CPU cores, and one gigabyte of memory:
$ qemu-system-x86_64 -accel nvmm
-cpu max -smp cpus=2 -m 1G \
-display sdl,gl=on -vga vmware \
-cdrom NetBSD-9.1-amd64.iso
The guest system will be much slower without acceleration as every CPU
instruction will have to be emulated.
You should also be able to see the virtual machine running with nvmmctl(8):
$ nvmmctl list
Machine ID VCPUs RAM Owner PID Creation Time
---------- ----- ---- --------- ------------------------
0 2 147M 10982 Sat May 8 10:09:59 2021
14.2.2. Ãreating a virtual disk
Generally, you will want to create a virtual drive to contain your virtual
machine on the host. We'll want to create a qcow2 image because it provides
better performance and is more versatile than a raw image:
$ qemu-img create -f qcow2 netbsd.qcow2 16G
A VirtIO block device provides the best performance. Add the following
arguments to qemu-system-x86_64 to use it:
-drive file=netbsd.qcow2,if=none,id=hd0 \
-device virtio-blk-pci,drive=hd0
Older operating systems may not have VirtIO drivers, in which case you can use
a normal emulated disk:
-hda netbsd.qcow2
14.2.3. Ádding entropy to the guest
Operating systems require a good source of randomness for system security,
cryptography, and so on. In a VM, this is ideally provided by the host machine,
which has greater access to the underlying hardware. You can easily attach a
VirtIO random number generator device with the following arguments to QEMU:
-object rng-random,filename=/dev/urandom,id=viornd0 \
-device virtio-rng-pci,rng=viornd0
This requires no extra configuration on the host machine.
Entropy is generally required for secure communications. For more information
on entropy, refer to entropy(7).
14.2.4. Õsing networking
The simplest way to set up networking with QEMU is so-called "user networking".
This will mean raw socket operations like ping(8) won't work, but normal TCP/IP
protocols like HTTP/FTP/etc will work. Another way is with bridged networking,
see Section4.3, "Configuring bridged networking on a NetBSD host".
The most performant device type is virtio-net-pci:
-netdev user,id=vioif0 -device virtio-net-pci,netdev=vioif0
To use older guest operating systems that don't support VirtIO, Intel Gigabit
Ethernet is a good choice:
-netdev user,id=wm0 -device e1000,netdev=wm0
Or an AMD PCnet card, for very old guest operating systems:
-netdev user,id=pcn0 -device pcnet,netdev=pcn0
14.2.5. Õsing audio
On a NetBSD host, the following QEMU arguments may be used to enable audio:
-audiodev oss,id=oss,out.dev=/dev/audio,in.dev=/dev/audio \
-device ac97,audiodev=oss
ac97 is the classic standardized sound driver for x86 systems.
You may wish to change the /dev/audioX device being used, see Chapter0, Audio
.
You may need to adjust things further to get smooth playback, see
Section4.4.3, "Smooth audio playback and latency in VMs".
14.2.6. Õsing graphics (or no graphics)
These arguments will create an X11 window with OpenGL enabled (for smooth
scaling if the window is resized), using a VMware-compatible VGA device, and an
emulated USB tablet:
-display sdl,gl=on -vga vmware \
-usb -device usb-tablet,bus=usb-bus.0
There is a VMware video driver included with X11 on NetBSD, so the display will
automatically configure when startx(1) runs and can be adjusted with xrandr(1).
An emulated USB tablet will provide a better mouse experience in QEMU because
it provides exact window co-ordinates to the VM. However, some older operating
systems might not support a USB tablet, in which case the usb-tablet line
should be omitted.
A VNC display will allow remote access from a VNC client like net/tigervnc,
useful when running QEMU with --daemonize on a server:
-display vnc=unix:/home/nia/.qemu-myvm-vnc -vga vmware
A simpler option is a curses display, preferable for systems that don't need
more than text output in a terminal:
-display curses
For more information on configuring X11, see Chapter, X.
For more information on securely configuring VNC, see QEMU's online
documentation on VNC.
14.3. Ãonfiguring bridged networking on a NetBSD host
While QEMU user networking is easy to use and doesn't require root privileges,
it's generally slower than bridged networking using a tap(4) device, and
doesn't allow the use of diagnostic tools like ping(8) inside the guest.
To configure bridged networking on a NetBSD host, you must first make note of
your host machine's primary network interace. Find the one with an address
assigned and a route to the outside world with ifconfig(8).
In this example, the host machine's primary interface is wm0. All of these
commands run on the host machine.
Create a virtual tap(4) interface:
# ifconfig tap0 create
# ifconfig tap0 descr "NetBSD VM" up
Create a bridge(4) connecting the actual interface and the virtual interface:
# ifconfig bridge0 create
# ifconfig bridge0 descr "LAN VM bridge" up
# brconfig bridge0 add tap0 add wm0
Configure NetBSD to do this all at boot time by editing /etc/ifconfig.tap0:
create
descr "NetBSD VM" up
! ifconfig bridge0 create
! ifconfig bridge0 descr "LAN VM bridge" up
! brconfig bridge0 add tap0 add wm0
You can now pass the arguments to QEMU to run with bridged networking:
-netdev tap,id=tap0,ifname=tap0,script=no -device virtio-net-pci,netdev=tap0
For more information on NetBSD network configuration, see Chapter6, Setting
up TCP/IP on NetBSD in practice.
14.4. Îotes on using NetBSD as a guest
14.4.1. Õnclean VM shutdown, data recovery, and fsck
AVOID UNCLEAN SHUTDOWNS! This means pressing Ctrl+C or killing the virtual
machine. In QEMU, the disks will rarely be synced, and data loss will almost
certainly occur.
You may wish to add the log,noatime mount options in /etc/fstab next to rw to
speed up fsck(8). You can also enable the sync option, but this will
significantly decrease performance.
Always shut down NetBSD safely using the shutdown(8) command and make backups.
14.4.2. ÎetBSD VMs lacking IPv6
QEMU's networking will sometimes configure an invalid IPv6 route on IPv4-only
configurations, meaning programs like the NetBSD packaging tools will prefer
IPv6 and spend a long time timing out before succeeding.
Work around this by editing /etc/rc.conf to tell dhcpcd(8) to ignore IPv6:
dhcpcd=YES
dhcpcd_flags="-4"
14.4.3. Ómooth audio playback and latency in VMs
Virtual machines cannot generally provide the same smooth playback at low
latency that real hardware provides. For smooth playback, you may need to
increase NetBSD's audio latency inside the VM:
$ sysctl -w hw.audio0.blk_ms=100
To set this automatically automatically at boot time, add it to /etc/
sysctl.conf.
You can test audio output in the VM. Ensure that audiocfg(1) plays a continuous
beep for each channel:
$ audiocfg test 0
14.4.4. Ãhanging the console resolution in an x86 VM
Note
On physical hardware where the display resolution is already set properly by
the kernel, doing this will disable graphical acceleration.
If you want to increase the size of the x86 console, enter the following at the
NetBSD boot prompt:
> vesa 1024x768x32
This setting can be made permanent in /boot.cfg.
Chapter5. Ôhe cryptographic device driver (CGD)
Table of Contents
15.1. Overview
15.1.1. Why use disk encryption?
15.1.2. Logical Disk Drivers
15.1.3. Availability
15.2. Components of the Crypto-Graphic Disk system
15.2.1. Kernel driver pseudo-device
15.2.2. Ciphers
15.2.3. Obsolete Ciphers
15.2.4. Verification Methods
15.3. Example: encrypting your disk
15.3.1. Preparing the disk
15.3.2. Scrubbing the disk
15.3.3. Creating the cgd
15.3.4. Modifying configuration files
15.3.5. Restoring data
15.4. Example: encrypted CDs/DVDs
15.4.1. Creating an encrypted CD/DVD
15.4.2. Using an encrypted CD/DVD
15.5. Example: encrypted iSCSI devices
15.5.1. Creating an encrypted iSCSI device
15.5.2. Device Initialisation
15.5.3. Unmounting the Encrypted Device
15.5.4. Normal Usage
15.6. Suggestions and Warnings
15.6.1. Using a random-key cgd for swap
15.6.2. Warnings
15.7. Further Reading
The cgd driver provides functionality which allows you to use disks or
partitions for encrypted storage. After providing the appropriate key, the
encrypted partition is accessible using cgd pseudo-devices.
15.1. Ïverview
People often store sensitive information on their hard disks and are concerned
about this information falling into the wrong hands. This is particularly
relevant to users of laptops and other portable devices, or portable media,
which might be stolen or accidentally misplaced.
15.1.1. ×hy use disk encryption?
File-oriented encryption tools like GnuPG are great for encrypting individual
files, which can then be sent across untrusted networks as well as stored
encrypted on disk. But sometimes they can be inconvenient, because the file
must be decrypted each time it is to be used; this is especially cumbersome
when you have a large collection of files to protect. Any time a security tool
is cumbersome to use, there's a chance you'll forget to use it properly,
leaving the files unprotected for the sake of convenience.
Worse, readable copies of the encrypted contents might still exist on the hard
disk. Even if you overwrite these files (using rm -P) before unlinking them,
your application software might make temporary copies you don't know about, or
have been paged to swapspace--and even your hard disk might have silently
remapped failing sectors with data still in them.
The solution is to simply never write the information unencrypted to the hard
disk. Rather than taking a file-oriented approach to encryption, consider a
block-oriented approach--a virtual hard disk, that looks just like a normal
hard disk with normal filesystems, but which encrypts and decrypts each block
on the way to and from the real disk.
15.1.2. Ìogical Disk Drivers
The cgd device looks and behaves to the rest of the operating system like any
other disk driver. Rather than driving real hardware directly, it provides a
logical function layered on top of another block device. It has a special
configuration program, cgdconfig, to create and configure a cgd device and
point it at the underlying disk device that will hold the encrypted data.
NetBSD includes several other similar logical block devices, each of which
provides some other function where cgd provides encryption. You can stack
several of these logical block devices together: cgd on top of vnd is handy to
make an encrypted volume in a regular file without repartitioning, or you can
make an encrypted raid to protect your encrypted data against hard disk failure
as well.
Once you have created a cgd disk, you can use disklabel to divide it up into
partitions, swapctl to enable swapping to those partitions or newfs to make
filesystems, then mount and use those filesystems, just like any other new
disk.
15.1.3. Ávailability
The cgd driver was written by Roland C. Dowdeswell, and introduced in the
NetBSD 2.0 release.
15.2. Ãomponents of the Crypto-Graphic Disk system
A number of components and tools work together to make the cgd system
effective.
15.2.1. Ëernel driver pseudo-device
To use cgd you need a kernel with support for the cgd pseudo-device. Make sure
the sure the module is loaded:
# modload cgd
If the cgd driver was not already present/loaded (it is loaded by default in
some ports), add cgd to /etc/modules.conf.
15.2.2. Ãiphers
The following ciphers are supported:
adiantum (key size: 256 bits)
The Adiantum tweakable wide-block cipher. The Adiantum tweak for each disk
sector is taken to be the little-endian encoding of the disk sector number.
Adiantum provides the best security by encrypting entire disk sectors at a
time (512 bytes), and generally provides the best performance on machines
without CPU support for accelerating AES.
aes-cbc (key sizes: 128, 192, or 256 bits)
AES in CBC mode. The CBC initialization vector for each disk sector is
chosen to be the encryption under AES of the little-endian encoding of the
disk sector number. The default key length is 128 bits.
aes-xts (key sizes: 256 or 512 bits)
AES in XTS mode. The XTS tweak for each disk sector is chosen to be the
little-endian encoding of the disk sector number. AES-XTS uses a 256-bit or
512-bit key, composed of a pair of AES-128 or AES-256 keys. The default key
length is 256, meaning AES-128.
15.2.3. Ïbsolete Ciphers
The following obsolete ciphers are supported for compatibility with old disks.
WARNING: These obsolete ciphers are implemented without timing side channel
protection, so, for example, JavaScript code in a web browser that can measure
the timing of disk activity may be able to recover the secret key. These are
also based on 64-bit block ciphers and are therefore unsafe for disks much
larger than a gigabyte. You should not use these except where compatibility
with old disks is necessary.
3des-cbc (key size: 192 bits)
3DES (Triple DES with EDE3) in CBC mode. The CBC initialization vector for
each disk sector is chosen to be the encryption under 3DES of the
little-endian encoding of the disk sector number, which has no impact on
security but reduces performance.
Note: Internally, the "parity bits" of the 192-bit key are ignored, so
there are only 168 bits of key material, and owing to generic attacks on
64-bit block ciphers and to meet-in-the-middle attacks on compositions of
ciphers as in EDE3 the security is much lower than one might expect even
for a 168-bit key.
blowfish-cbc (key sizes: 40, 48, 56, 64, ?, 432, 440, or 448 bits)
Blowfish in CBC mode. The CBC initialization vector for each disk sector is
chosen to be the encryption under Blowfish of the little-endian encoding of
the disk sector number. It is strongly encouraged that keys be at least 128
bits long. There are no performance advantages of using shorter keys. The
default key length is 128 bits.
15.2.4. Öerification Methods
cgdconfig can examine the disk to verify that it was decrypted using the
correct key. The following verification methods are available:
none
No verification is performed. This is dangerous unless you are configuring
a new cgd device for the first time, because the key is not verified at
all. Entering the wrong passphrase, for example, may destroy any data on
the volume--any data read will be garbage, and any data written will turn
into garbage if you ever re-open the cgd volume with the correct
passphrase.
disklabel
cgdconfig scans for a valid BSD disklabel; see disklabel(5) and disklabel
(8).
mbr
cgdconfig scans for a valid Master Boot Record, traditionally used on PCs;
see fdisk(8).
gpt
cgdconfig scans for a valid GUID partition table; see gpt(8).
ffs
cgdconfig scans for a valid FFS file system, the default file system used
in NetBSD; see mount_ffs(8).
re-enter
Rather than scanning anything on disk, cgdconfig will compute the key
twice--for example, by asking the user to enter the passphrase twice--and
fail if the results are different.
15.3. Åxample: encrypting your disk
This section works through a step-by-step example of converting an existing
system to use cgd, performing the following actions:
1. Preparing the disk and partitions
2. Scrub off all data
3. Create the cgd
4. Adjust config-files
5. Restoring your backed-up files to the encrypted disk
15.3.1. Ðreparing the disk
First, decide which filesystems you want to move to an encrypted device. You're
going to need to leave at least the small root (/) filesystem unencrypted, in
order to load the kernel and run init, cgdconfig and the rc.d scripts that
configure your cgd. In this example, we'll encrypt everything except the root
(/) filesystem.
We are going to delete and re-make partitions and filesystems, and will require
a backup to restore the data. So make sure you have a current, reliable backup
stored on a different disk or machine. Do your backup in single-user mode, with
the filesystems unmounted, to ensure you get a clean dump. Make sure you back
up the disklabel of your hard disk as well, so you have a record of the
partition layout before you started.
With the system at single user, / mounted read-write and everything else
unmounted, use disklabel to delete all the data partitions you want to move
into cgd.
Then make a single new partition in all the space you just freed up, say, wd0e.
Set the partition type for this partition to cgd Though it doesn't really
matter what it is, it will help remind you that it's not a normal filesystem
later. When finished, label the disk to save the new partition table.
15.3.2. Ócrubbing the disk
We have removed the partition table information, but the existing filesystems
and data are still on disk. Even after we make a cgd device, create
filesystems, and restore our data, some of these disk blocks might not yet be
overwritten and still contain our data in plaintext. This is especially likely
if the filesystems are mostly empty. We want to scrub the disk before we go
further.
We could use dd to copy /dev/zero over the new wd0e partition, but this will
leave our disk full of zeros, except where we've written encrypted data later.
We might not want to give an attacker any clues about which blocks contain real
data, and which are free space, so we want to write "noise" into all the disk
blocks. So we'll create a temporary cgd, configured with a random, unknown key.
First, we configure a cgd to use a random key:
# cgdconfig -s cgd0 /dev/wd0e aes-xts 256 < /dev/urandom
Now we can write zeros into the raw partition of our cgd (/dev/rcgd0d on NetBSD
/i386 and amd64, /dev/rcgd0c on most other platforms):
# dd if=/dev/zero of=/dev/rcgd0d bs=64k
The encrypted zeros will look like random data on disk. This might take a while
if you have a large disk. Once finished, unconfigure the random-key cgd:
# cgdconfig -u cgd0
15.3.3. Ãreating the cgd
The cgdconfig program, which manipulates cgd devices, uses parameters files to
store such information as the encryption type, key length, and a random
password salt for each cgd. These files are very important, and need to be kept
safe--without them, you will not be able to decrypt the data!
We'll generate a parameters file and write it into the default location (make
sure the directory /etc/cgd exists and is mode 700):
# cgdconfig -g -V disklabel -o /etc/cgd/wd0e aes-cbc 256
This creates a parameters file /etc/cgd/wd0e describing a cgd using the aes-cbc
cipher method, a key verification method of disklabel, and a key length of 256
bits. It will look something like this:
algorithm aes-cbc;
iv-method encblkno;
keylength 256;
verify_method disklabel;
keygen pkcs5_pbkdf2/sha1 {
iterations 6275;
salt AAAAgHTg/jKCd2ZJiOSGrgnadGw=;
};
Note
Consider this file being SACRED, BACK IT UP , and BACK IT UP AGAIN!
Tip
When creating the parameters file, cgdconfig reads from /dev/random to create
the password salt. This read may block if there is not enough collected entropy
in the random pool. This is unlikely, especially if you just finished
overwriting the disk as in the previous step, but if it happens you can press
keys on the console and/or move your mouse until the rnd device gathers enough
entropy.
Now it's time to create our cgd, for which we'll need a passphrase. This
passphrase needs to be entered every time the cgd is opened, which is usually
at each reboot. The encryption key is derived from this passphrase and the
salt. Make sure you choose something you won't forget, and others won't guess.
The first time we configure the cgd, there is no valid disklabel on the logical
device, so the validation mechanism we want to use later won't work. We
override it this one time:
# cgdconfig -V re-enter cgd0 /dev/wd0e
This will prompt twice for a matching passphrase, just in case you make a typo,
which would otherwise leave you with a cgd encrypted with a passphrase that's
different to what you expected.
Now that we have a new cgd, we need to partition it and create filesystems.
Recreate your previous partitions with all the same sizes, with the same letter
names.
Tip
Remember to use the disklabel -I argument, because you're creating an initial
label for a new disk.
Note
Although you want the sizes of your new partitions to be the same as the old,
unencrypted ones, the offsets will be different because they're starting at the
beginning of this virtual disk.
Then, use newfs to create filesystems on all the relevant partitions. This time
your partitions will reflect the cgd disk names, for example:
# newfs /dev/rcgd0h
15.3.4. Íodifying configuration files
We've moved several filesystems to another (logical) disk, and we need to
update /etc/fstab accordingly. Each partition will have the same letter (in
this example), but will be on cgd0 rather than wd0. So you'll have /etc/fstab
entries something like this:
/dev/wd0a / ffs rw 1 1
/dev/cgd0b none swap sw 0 0
/dev/cgd0b /tmp mfs rw,-s=132m 0 0
/dev/cgd0e /var ffs rw 1 2
/dev/cgd0f /usr ffs rw 1 2
/dev/cgd0h /home ffs rw 1 2
Note
/tmp should be a separate filesystem, either mfs or ffs, inside the cgd, so
that your temporary files are not stored in plain text in the / filesystem.
Each time you reboot, you're going to need your cgd configured early, before
fsck runs and filesystems are mounted.
Put the following line in /etc/cgd/cgd.conf:
cgd0 /dev/wd0e
This will use /etc/cgd/wd0e as config file for cgd0.
To finally enable cgd on each boot, put the following line into /etc/rc.conf:
cgd=YES
You should now be prompted for /dev/cgd0's passphrase whenever /etc/rc starts.
15.3.5. Òestoring data
Next, mount your new filesystems, and restore your data into them. It often
helps to have /tmp mounted properly first, as restore can use a fair amount of
temporary space when extracting a large dumpfile.
To test your changes to the boot configuration, umount the filesystems and
unconfigure the cgd, so when you exit the single-user shell, rc will run like
on a clean boot, prompting you for the passphrase and mounting your filesystems
correctly. Now you can bring the system up to multi-user, and make sure
everything works as before.
15.4. Åxample: encrypted CDs/DVDs
15.4.1. Ãreating an encrypted CD/DVD
cgd(4) provides highly secure encryption of whole partitions or disks.
Unfortunately, creating "normal" CDs is not disklabeling something and running
newfs on it. Neither can you just put a CDR into the drive, configure cgd and
assume it to write encrypted data when syncing. Standard CDs contain at least
an ISO-9660 filesystem created with mkisofs(8) from the sysutils/cdrtools
package. ISO images may not contain disklabels or cgd partitions.
But of course CD reader/writer hardware doesn't care about filesystems at all.
You can write raw data to the CD if you like--or an encrypted FFS filesystem,
which is what we'll do here. But be warned, there is NO way to read this CD
with any OS except NetBSD--not even other BSDs due to the lack of cgd.
The basic steps when creating an encrypted CD are:
* Create an (empty) imagefile
* Register it as a virtual disk using vnd(4)
* Configure cgd inside the vnd disk
* Copy content to the cgd
* Unconfigure all (flush!)
* Write the image on a CD
The first step when creating an encrypted CD is to create a single image file
with dd. The image may not grow, so make it large enough to allow all CD
content to fit into. Note that the whole image gets written to the CD later, so
creating a 700 MB image for 100 MB content will still require a 700 MB write
operation to the CD. Some info on DVDs here: DVDs are only 4.7 GB in marketing
language. 4.7GB = 4.7 x 1024 x 1024 x 1024 = 5046586573 bytes. In fact, a DVD
can only approximately hold 4.7 x 1000 x 1000 x 1000 = 4700000000 bytes, which
is about 4482 MB or about 4.37 GB. Keep this in mind when creating DVD images.
Don't worry for CDs, they hold "real" 700 MB (734003200 Bytes).
Invoke all following commands as root!
For a CD:
# dd if=/dev/zero of=image.img bs=1m count=700
or, for a DVD:
# dd if=/dev/zero of=image.img bs=1m count=4482
Now configure a vnd(4)-pseudo disk with the image:
# vnconfig vnd0 image.img
In order to use cgd, a so-called parameter file, describing encryption
parameters and a containing "password salt" must be generated. We'll call it /
etc/cgd/image here. You can use one parameter file for several encrypted
partitions (I use one different file for each host and a shared file image for
all removable media, but that's up to you).
AES-CBC with a keylength of 256 bits will be used in this example. Refer to cgd
(4) and cgdconfig(8) for further details and alternative ciphers.
The following command will create the parameter file as /etc/cgd/image. YOU DO
NOT WANT TO INVOKE THE FOLLOWING COMMAND AGAIN after you burnt any CD, since a
recreated parameter file is a lost parameter file and you'll never access your
encrypted CD again (the "salt" this file contains will differ among each call).
Consider this file being SACRED, BACK IT UP and BACK IT UP AGAIN! Use switch -V
to specify verification method "disklabel" for the CD (cgd cannot detect
whether you entered a valid password for the CD later when mounting it
otherwise).
# cgdconfig -g -V disklabel aes-cbc 256 > /etc/cgd/image
Now it's time to configure a cgd for our vnd drive. (Replace slice "d" with "c"
for all platforms that use "c" as the whole disk (where "sysctl
kern.rawpartition" prints "2", not "3"); if you're on i386 or amd64, "d" is OK
for you):
# cgdconfig -V re-enter cgd1 /dev/vnd0d /etc/cgd/image
The "-V re-enter" option is necessary as long as the cgd doesn't have a
disklabel yet so we can access and configure it. This switch asks for a
password twice and uses it for encryption.
Now it's time to create a disklabel inside the cgd. The defaults of the label
are ok, so invoking disklabel with
# disklabel -e -I cgd1
and leaving vi with ":wq" immediately will do.
Let's create a filesystem on the cgd, and finally mount it somewhere:
# newfs /dev/rcgd1a
# mount /dev/cgd1a /mnt
The cgd is alive! Now fill /mnt with content. When finished, reverse the
configuration process. The steps are:
1. Unmounting the cgd1a:
# umount /mnt
2. Unconfiguring the cgd:
# cgdconfig -u cgd1
3. Unconfiguring the vnd:
# vnconfig -u vnd0
The following commands are examples to burn the images on CD or DVD. Please
adjust the dev= for cdrecord or the /dev/rcd0d for growisofs. Note the "rcd0d"
is necessary with NetBSD. Growisofs is available in the sysutils/dvd+rw-tools
package. Again, use "c" instead of "d" if this is the raw partition on your
platform.
Finally, write the image file to a CD:
# cdrecord dev=/dev/rcd0d -v image.img
...or to a DVD:
# growisofs -dvd-compat -Z /dev/rcd0d=image.img
Congratulations! You've just created a really secure CD!
15.4.2. Õsing an encrypted CD/DVD
After creating an encrypted CD as described above, we're not done yet--what
about mounting it again? One might guess, configuring the cgd on /dev/cd0d is
enough--no, it is not.
NetBSD cannot access FFS file systems on media that is not 512 bytes/sector
format. It doesn't matter that the cgd on the CD is, since the CD's disklabel
the cgd resides in has 2048 bytes/sector.
But the CD driver cd(4) is smart enough to grant "write" access to the
(emulated) disklabel on the CD. So before configuring the cgd, let's have a
look at the disklabel and modify it a bit:
# disklabel -e cd0
# /dev/rcd0d:
type: ATAPI
disk: mydisc
label: fictitious
flags: removable
bytes/sector: 2048 # -- Change to 512 (= orig / 4)
sectors/track: 100 # -- Change to 400 (= orig * 4)
tracks/cylinder: 1
sectors/cylinder: 100 # -- Change to 400 (= orig * 4)
cylinders: 164
total sectors: 16386 # -- Change to value of slice "d" (=65544)
rpm: 300
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
4 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 65544 0 4.2BSD 0 0 0 # (Cyl. 0 - 655+)
d: 65544 0 ISO9660 0 0 # (Cyl. 0 - 655+)
If you don't want to do these changes every time by hand, you can use Florian
Stoehr's tool neb-cd512 which is (at time of writing this) in pkgsrc-wip and
will move to sysutils/neb-cd512 soon. You can also download the neb-cd512
source from http://sourceforge.net/projects/neb-stoehr/ (be sure to use
neb-cd512, not neb-wipe!).
It is invoked with the disk name as parameter, by root:
# neb-cd512 cd0
Now as the disklabel is in 512 b/s format, accessing the CD is as easy as:
# cgdconfig cgd1 /dev/cd0d /etc/cgd/image
# mount -o ro /dev/cgd1a /mnt
Note that the cgd MUST be mounted read-only or you'll get illegal command
errors from the cd(4) driver which can in some cases make even mounting a
CD-based cgd impossible!
Now we're done! Enjoy your secure CD!
# ls /mnt
Remember you have to reverse all steps to remove the CD:
# umount /mnt
# cgdconfig -u cgd1
# eject cd0
15.5. Åxample: encrypted iSCSI devices
15.5.1. Ãreating an encrypted iSCSI device
To encrypt the iSCSI device, we use the NetBSD iSCSI initiator, available in
NetBSD-6 and newer, and the standard cgd device. In all, setting up an
encrypted device in this manner should take less than 15 minutes, even for
someone unfamiliar with iSCSI or cgd.
The approach is to layer a vnd on top of the "storage" file presented by the
iSCSI target. This is exactly the same as normal. On top of that vnd, we layer
a cgd device, which ensures that all data is encrypted on the iSCSI device.
WARNING: cgd only keeps the content of the volume secret--it doesn't keep the
access patterns secret, and it doesn't prevent or even detect a malicious
network or iSCSI target tampering with the volume.
15.5.2. Äevice Initialisation
Firstly, the initiator is started, pointing at the machine which is presenting
the iSCSI storage (i.e. the machine on which the iSCSI target is running). In
this example, the target is running on the same machine as the initiator (a
laptop called, in a moment of inspiration, inspiron1300). A 50 MB iSCSI target
is being presented as target1.
# iscsi-initiator -u agc -h inspiron1300.wherever.co.uk /mnt &
[1] 11196
# df
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/dk0 28101396 20862004 5834324 78% /
kernfs 1 1 0 100% /kern
procfs 4 4 0 100% /proc
ptyfs 1 1 0 100% /dev/pts
/dev/puffs 0 0 0 100% /mnt
Looking at the last line, we can see that the initiator is running via the
puffs device.
A vnd device is created on top of the storage which the target is presenting:
# vnconfig vnd0 /mnt/inspiron1300.wherever.co.uk/target1/storage
A disklabel which is offset 63 blocks into the iSCSI device needs to be added.
This is so that the encrypted device which we shall put on top of the vnd does
not clash with the vnd's label. The cgd's type should be set to "cgd".
# disklabel -e vnd0
# /dev/rvnd0d:
type: vnd
disk: vnd
label: fictitious
flags:
bytes/sector: 512
sectors/track: 32
tracks/cylinder: 64
sectors/cylinder: 2048
cylinders: 50
total sectors: 102400
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
4 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 102336 63 cgd 2048 16384 28360 # (Cyl. 0 - 49)
d: 102400 0 unused 0 0 # (Cyl. 0 - 49)
The cgd device can now be created on the vnd device
# cgdconfig -s cgd0 /dev/vnd0a aes-xts 256 < /dev/urandom
and the cgd device's storage zeroed
# dd if=/dev/zero of=/dev/rcgd0d bs=32k
dd: /dev/rcgd0d: Invalid argument
1601+0 records in
1600+0 records out
52428800 bytes transferred in 16.633 secs (3152095 bytes/sec)
Unconfigure the cgd device and write a disklabel using the verification method
onto the cgd. Note: sometimes, this process does not always complete properly,
and so it has to be repeated.
# cgdconfig -g -V disklabel -o /etc/cgd/vnd0a aes-cbc 256
cgdconfig: could not calibrate pkcs5_pbkdf2
cgdconfig: Failed to generate defaults for keygen
# cgdconfig -g -V disklabel -o /etc/cgd/vnd0a aes-cbc 256
A password can then be added to the cgd device
# cgdconfig -V re-enter cgd0 /dev/vnd0a
/dev/vnd0a's passphrase:
re-enter device's passphrase:
Then create a disklabel inside the cgd itself
# disklabel -I -e cgd0
# /dev/rcgd0d:
type: cgd
disk: cgd
label: fictitious
flags:
bytes/sector: 512
sectors/track: 2048
tracks/cylinder: 1
sectors/cylinder: 2048
cylinders: 49
total sectors: 102336
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
4 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 102336 0 4.2BSD 2048 16384 28360 # (Cyl. 0 - 49*)
d: 102336 0 unused 0 0 # (Cyl. 0 - 49*)
Having placed a disklabel inside the cgd, we can now make a filesystem on
there:
# newfs /dev/rcgd0a
/dev/rcgd0a: 50.0MB (102336 sectors) block size 8192, fragment size 1024
using 4 cylinder groups of 12.49MB, 1599 blks, 3136 inodes.
super-block backups (for fsck_ffs -b #) at:
32, 25616, 51200, 76784,
the new file system in the cgd can now be mounted
# df
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/dk0 28101396 20910216 5786112 78% /
kernfs 1 1 0 100% /kern
procfs 4 4 0 100% /proc
ptyfs 1 1 0 100% /dev/pts
/dev/puffs 0 0 0 100% /mnt
# mount /dev/cgd0a /iscsi
# df
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/dk0 28101396 20910216 5786112 78% /
kernfs 1 1 0 100% /kern
procfs 4 4 0 100% /proc
ptyfs 1 1 0 100% /dev/pts
/dev/puffs 0 0 0 100% /mnt
/dev/cgd0a 49519 1 47043 0% /iscsi
The new file system, mounted on /iscsi, can now be used as normal.
15.5.3. Õnmounting the Encrypted Device
The device can be freed up using the following commands
# umount /iscsi
# cgdconfig -u cgd0
# vnconfig -u vnd0
15.5.4. Îormal Usage
In normal usage, the device can be mounted. Firstly, the initiator must be
configured to connect to the device:
# vnconfig vnd0 /mnt/inspiron1300.wherever.co.uk/target1/storage
# cgdconfig cgd0 /dev/vnd0a
/dev/vnd0a's passphrase:
# mount /dev/cgd0a /iscsi
# ls -al /iscsi
total 3
drwxr-xr-x 2 root wheel 512 Jan 1 1970 .
drwxr-xr-x 35 root wheel 1536 Jan 5 08:59 ..
# df
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/dk0 28101396 20910100 5786228 78% /
kernfs 1 1 0 100% /kern
procfs 4 4 0 100% /proc
ptyfs 1 1 0 100% /dev/pts
/dev/puffs 0 0 0 100% /mnt
/dev/cgd0a 49519 1 47043 0% /iscsi
15.6. Óuggestions and Warnings
You now have your filesystems encrypted within a cgd. When your machine is shut
down, the data is protected, and can't be decrypted without the passphrase.
However, there are still some dangers you should be aware of, and more you can
do with cgd. This section documents several further suggestions and warnings
that will help you use cgd effectively.
* Use multiple cgd's for different kinds of data, one mounted all the time
and others mounted only when needed.
* Use a cgd configured on top of a vnd made from a file on a remote network
fileserver (NFS, SMBFS, CODA, etc) to safely store private data on a shared
system. This is similar to the procedure for using encrypted CDs and DVDs
described in Section5.4, "Example: encrypted CDs/DVDs".
15.6.1. Õsing a random-key cgd for swap
The following section will be replaced in NetBSD 10 by a sysctl knob "
vm.swap_encrypt=1", which provides better security and simpler setup.
You may want to use a dedicated random-key cgd for swap space, regenerating the
key each reboot. The advantage of this is that once your machine is rebooted,
any sensitive program memory contents that may have been paged out are
permanently unrecoverable, because the decryption key is never known to you.
We created a temporary cgd with a random key when scrubbing the disk in the
example above, using a shorthand cgdconfig -s invocation to avoid creating a
parameters file.
The cgdconfig params file includes a "randomkey" keygen method. This is more
appropriate for "permanent" random-key configurations, and facilitates the easy
automatic configuration of these volumes at boot time.
For example, if you wanted to convert your existing /dev/wd0b partition to a
dedicated random-key cgd1, use the following command to generate /etc/cgd/wd0b:
# cgdconfig -g -o /etc/cgd/wd0b -V none -k randomkey blowfish-cbc
When using the randomkey keygen method, only verification method "none" can be
used, because the contents of the new cgd are effectively random each time (the
previous data decrypted with a random key). Likewise, the new disk will not
have a valid label or partitions, and swapctl will complain about configuring
swap devices not marked as such in a disklabel.
In order to automate the process of labeling the disk, prepare an appropriate
disklabel and save it to a file, for example /etc/cgd/wd0b.disklabel. Please
refer to disklabel(8) for information about how to use disklabel to set up a
swap partition.
On each reboot, to restore this saved label to the new cgd, create the /etc/
rc.conf.d/cgd file as below:
swap_device="cgd1"
swap_disklabel="/etc/cgd/wd0b.disklabel"
start_postcmd="cgd_swap"
cgd_swap()
{
if [ -f $swap_disklabel ]; then
disklabel -R -r $swap_device $swap_disklabel
fi
}
The same technique could be extended to encompass using newfs to re-create an
ffs filesystem for /tmp if you didn't want to use mfs.
15.6.2. ×arnings
Avoid data loss by making sure you can always recover your passphrase and
parameters file. Protect the parameters file from disclosure, perhaps by
storing it on removable media as above, because the salt it contains helps
protect against dictionary attacks on the passphrase.
Keeping the data encrypted on your disk is all very well, but what about other
copies? You already have at least one other such copy (the backup we used
during this setup), and it's not encrypted. Piping dump through file-based
encryption tools like gpg can be one way of addressing this issue, but make
sure you have all the keys and tools you need to decrypt it to restore after a
disaster.
Like any form of software encryption, the cgd key stays in kernel memory while
the device is configured, and may be accessible to privileged programs and
users, such as /dev/kmem grovellers. Taking other system security steps, such
as running with elevated securelevel, is highly recommended.
Once the cgd volumes are mounted as normal filesystems, their contents are
accessible like any other file. Take care of file permissions and ensure your
running system is protected against application and network security attack.
Avoid using suspend/resume, especially for laptops with a BIOS suspend-to-disk
function. If an attacker can resume your laptop with the key still in memory,
or read it from the suspend-to-disk memory image on the hard disk later, the
whole point of using cgd is lost.
15.7. Æurther Reading
The following resources contain more information on CGD and the cryptography
underlying it:
Bibliography
[nycbug-cgd] I want my cgd aka: I want an encrypted pseudo-device on my laptop.
[elric-cgd] Roland Dowdeswell and John Ioannidis. "The CryptoGraphic Disk
Driver". Proceedings of the FREENIX Track: 2003 USENIX Annual Technical
Conference. USENIX Association. 179-186. June 9-14, 2003.
[hubertf-cgd] Feyrer Hubert. CryptoGraphicFile (CGF), or how to keep sensitive
data on your laptop.
[adiantum] Paul Crowley and Eric Biggers. "Adiantum: length-preserving
encryption for entry-level processors". Transactions on Symmetric Cryptology.
2018. 4. International Association of Cryptologic Research. 39-61.
[fips46-3] FIPS PUB 46-3: Data Encryption Standard (DES). National Institute of
Standards and Technology. United States Department of Commerce. October 25,
1999, withdrawn May 19, 2005.
[fips197] FIPS PUB 197: Advanced Encryption Standard (DES). National Institute
of Standards and Technology. United States Department of Commerce. November
2001.
[nist-sp800-38a] Morris Dworkin. Recommendation for Block Cipher Modes of
Operation: Methods and Techniques. NIST Special Publication 800-38A. National
Institute of Standards and Technology. United States Department of Commerce.
December 2001.
[nist-sp800-38e] Morris Dworkin. Recommendation for Block Cipher Modes of
Operation: the XTS-AES Mode for Confidentiality on Storage Devices. NIST
Special Publication 800-38E. National Institute of Standards and Technology.
United States Department of Commerce. January 2010.
[blowfish] Bruce Schneier. The Blowfish Encryption Algorithm. superseded by
Twofish, superseded by Threefish. 1993.
[sweet32] Karthikeyan Bhargavan and Gaéôan Leurent. Sweet32: Birthday attacks
on 64-bit block ciphers in TLS and OpenVPN.
Chapter6. Ãoncatenated Disk Device (CCD) configuration
Table of Contents
16.1. Install physical media
16.2. Configure Kernel Support
16.3. Disklabel each volume member of the CCD
16.4. Configure the CCD
16.5. Initialize the CCD device
16.6. Create a 4.2BSD/UFS filesystem on the new CCD device
16.7. Mount the filesystem
The CCD driver allows the user to "concatenate" several physical disks into one
pseudo volume. While RAIDframe (see Chapter7, NetBSD RAIDframe) also allows
doing this to create RAID level 0 sets, it does not allow you to do striping
across disks of different geometry, which is where CCD comes in handy. CCD also
allows for an "interleave" to improve disk performance with a gained space
loss. This example will not cover that feature.
The steps required to setup a CCD are as follows:
1. Install physical media
2. Configure kernel support
3. Disklabel each volume member of the CCD
4. Configure the CCD conf file
5. Initialize the CCD device
6. Create a filesystem on the new CCD device
7. Mount the CCD filesystem
This example features a CCD setup on NetBSD/sparc 1.5. The CCD will reside on 4
SCSI disks in a generic external Sun disk pack chassis connected to the
external 50 pin SCSI port.
16.1. Énstall physical media
This step is at your own discretion, depending on your platform and the
hardware at your disposal.
From my DMESG:
Disk #1:
probe(esp0:0:0): max sync rate 10.00MB/s
sd0 at scsibus0 target 0 lun 0: <SEAGATE, ST32430N SUN2.1G, 0444> SCSI2 0/direct fixed
sd0: 2049 MB, 3992 cyl, 9 head, 116 sec, 512 bytes/sect x 4197405 sectors
Disk #2
probe(esp0:1:0): max sync rate 10.00MB/s
sd1 at scsibus0 target 1 lun 0: <SEAGATE, ST32430N SUN2.1G, 0444> SCSI2 0/direct fixed
sd1: 2049 MB, 3992 cyl, 9 head, 116 sec, 512 bytes/sect x 4197405 sectors
Disk #3
probe(esp0:2:0): max sync rate 10.00MB/s
sd2 at scsibus0 target 2 lun 0: <SEAGATE, ST11200N SUN1.05, 9500> SCSI2 0/direct fixed
sd2: 1005 MB, 1872 cyl, 15 head, 73 sec, 512 bytes/sect x 2059140 sectors
Disk #4
probe(esp0:3:0): max sync rate 10.00MB/s
sd3 at scsibus0 target 3 lun 0: <SEAGATE, ST11200N SUN1.05, 8808 > SCSI2 0
sd3: 1005 MB, 1872 cyl, 15 head, 73 sec, 512 bytes/sect x 2059140 sectors
16.2. Ãonfigure Kernel Support
The following kernel configuration directive is needed to provide CCD device
support. It is enabled in the GENERIC kernel:
pseudo-device ccd 4 # concatenated disk devices
In my kernel config, I also hard code SCSI ID associations to /dev device
entries to prevent bad things from happening:
sd0 at scsibus0 target 0 lun ?
# SCSI disk drives
sd1 at scsibus0 target 1 lun ?
# SCSI disk drives
sd2 at scsibus0 target 2 lun ?
# SCSI disk drives
sd3 at scsibus0 target 3 lun ?
# SCSI disk drives
sd4 at scsibus0 target 4 lun ?
# SCSI disk drives
sd5 at scsibus0 target 5 lun ?
# SCSI disk drives
sd6 at scsibus0 target 6 lun ?
# SCSI disk drives
16.3. Äisklabel each volume member of the CCD
Each member disk of the CCD will need a special file system established. In
this example, I will need to disklabel:
/dev/rsd0c
/dev/rsd1c
/dev/rsd2c
/dev/rsd3c
Note
Always remember to disklabel the character device, not the block device, in /
dev/r{s,w}d*
Note
On all platforms, the c slice is symbolic of the entire NetBSD partition and is
reserved.
You will probably want to remove any pre-existing disklabels on the disks in
the CCD. This can be accomplished in one of two ways with the dd(1) command:
# dd if=/dev/zero of=/dev/rsd0c bs=8k count=1
# dd if=/dev/zero of=/dev/rsd1c bs=8k count=1
# dd if=/dev/zero of=/dev/rsd2c bs=8k count=1
# dd if=/dev/zero of=/dev/rsd3c bs=8k count=1
If your port uses a MBR (Master Boot Record) to partition the disks so that the
NetBSD partitions are only part of the overall disk, and other OSs like Windows
or Linux use other parts, you can void the MBR and all partitions on disk by
using the command:
# dd if=/dev/zero of=/dev/rsd0d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd1d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd2d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd3d bs=8k count=1
This will make all data on the entire disk inaccessible. Note that the entire
disk is slice d on i386 (and some other ports), and c elsewhere (e.g. on
sparc). See the "kern.rawpartition" sysctl - "3" means "d", "2" means "c".
The default disklabel for the disk will look similar to this:
# disklabel -r sd0
[...snip...]
bytes/sector: 512
sectors/track: 116
tracks/cylinder: 9
sectors/cylinder: 1044
cylinders: 3992
total sectors: 4197405
[..snip...]
3 partitions:
# size offset fstype [fsize bsize cpg]
c: 4197405 0 unused 1024 8192 # (Cyl. 0 - 4020*)
You will need to create one "slice" on the NetBSD partition of the disk that
consumes the entire partition. The slice must begin at least one cylinder
offset from the beginning of the disk/partition to provide space for the
special CCD disklabel. The offset should be 1x sectors/cylinder (see following
note). Therefore, the "size" value should be "total sectors" minus 1x "sectors/
cylinder". Edit your disklabel accordingly:
# disklabel -e sd0
Note
The offset of a slice of type "ccd" must be a multiple of the "sectors/cylinder
" value.
Note
Be sure to export EDITOR=[path to your favorite editor] before editing the
disklabels.
Note
The slice must be fstype ccd.
Because there will only be one slice on this partition, you can recycle the c
slice (normally reserved for symbolic uses). Change your disklabel to the
following:
3 partitions:
# size offset fstype [fsize bsize cpg]
c: 4196361 1044 ccd # (Cyl. 1 - 4020*)
Optionally you can setup a slice other than c to use, simply adjust accordingly
below:
3 partitions:
# size offset fstype [fsize bsize cpg]
a: 4196361 1044 ccd # (Cyl. 1 - 4020*)
c: 4197405 0 unused 1024 8192 # (Cyl. 0 - 4020*)
Be sure to write the label when you have completed. Disklabel will object to
your disklabel and prompt you to re-edit if it does not pass its sanity checks.
16.4. Ãonfigure the CCD
Once all disks are properly labeled, you will need to generate a configuration
file, /etc/ccd.conf. The file does not exist by default, and you will need to
create a new one. The format is:
#ccd ileave flags component devices
Note
For the "ileave", if a value of zero is used then the disks are concatenated,
but if you use a value equal to the "sectors/track" number the disks are
interleaved.
Example in this case:
# more /etc/ccd.conf
ccd0 0 none /dev/sd0c /dev/sd1c /dev/sd2c /dev/sd3c
Note
The CCD driver expects block device files as components. Be sure not to use
character device files in the configuration.
16.5. Énitialize the CCD device
Once you are confident that your CCD configuration is sane, you can initialize
the device using the ccdconfig(8) command: Configure:
# ccdconfig -C -f /etc/ccd.conf
Unconfigure:
# ccdconfig -u -f /etc/ccd.conf
Initializing the CCD device will activate /dev entries: /dev/{,r}ccd#:
# ls -la /dev/{,r}ccd0*
brw-r----- 1 root operator 9, 0 Apr 28 21:35 /dev/ccd0a
brw-r----- 1 root operator 9, 1 Apr 28 21:35 /dev/ccd0b
brw-r----- 1 root operator 9, 2 May 12 00:10 /dev/ccd0c
brw-r----- 1 root operator 9, 3 Apr 28 21:35 /dev/ccd0d
brw-r----- 1 root operator 9, 4 Apr 28 21:35 /dev/ccd0e
brw-r----- 1 root operator 9, 5 Apr 28 21:35 /dev/ccd0f
brw-r----- 1 root operator 9, 6 Apr 28 21:35 /dev/ccd0g
brw-r----- 1 root operator 9, 7 Apr 28 21:35 /dev/ccd0h
crw-r----- 1 root operator 23, 0 Jun 12 20:40 /dev/rccd0a
crw-r----- 1 root operator 23, 1 Apr 28 21:35 /dev/rccd0b
crw-r----- 1 root operator 23, 2 Jun 12 20:58 /dev/rccd0c
crw-r----- 1 root operator 23, 3 Apr 28 21:35 /dev/rccd0d
crw-r----- 1 root operator 23, 4 Apr 28 21:35 /dev/rccd0e
crw-r----- 1 root operator 23, 5 Apr 28 21:35 /dev/rccd0f
crw-r----- 1 root operator 23, 6 Apr 28 21:35 /dev/rccd0g
crw-r----- 1 root operator 23, 7 Apr 28 21:35 /dev/rccd0h
16.6. Ãreate a 4.2BSD/UFS filesystem on the new CCD device
You may now disklabel the new virtual disk device associated with your CCD:
# disklabel -e ccd0
Once again, there will be only one slice, so you may either recycle the c slice
or create a separate slice for use.
# disklabel -r ccd0
# /dev/rccd0c:
type: ccd
disk: ccd
label: default label
flags:
bytes/sector: 512
sectors/track: 2048
tracks/cylinder: 1
sectors/cylinder: 2048
cylinders: 6107
total sectors: 12508812
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
# size offset fstype [fsize bsize cpg]
c: 12508812 0 4.2BSD 1024 8192 16 # (Cyl. 0 - 6107*)
The filesystem will then need to be formatted:
# newfs /dev/rccd0c
Warning: 372 sector(s) in last cylinder unallocated
/dev/rccd0c: 12508812 sectors in 6108 cylinders of 1 tracks, 2048 sectors
6107.8MB in 382 cyl groups (16 c/g, 16.00MB/g, 3968 i/g)
super-block backups (for fsck -b #) at:
[...]
16.7. Íount the filesystem
Once you have a created a file system on the CCD device, you can then mount the
file system against a mount point on your system. Be sure to mount the slice
labeled type ffs or 4.2BSD:
# mount /dev/ccd0c /mnt
Then:
# export BLOCKSIZE=1024; df
Filesystem 1K-blocks Used Avail Capacity Mounted on
/dev/sd6a 376155 320290 37057 89% /
/dev/ccd0c 6058800 1 5755859 0% /mnt
Congratulations, you now have a working CCD. To configure the CCD device at
boot time, set ccd=yes in /etc/rc.conf. You can adjust /etc/fstab to get the
filesystem mounted at boot:
/dev/ccd0c /home ffs rw 1 2
Chapter7. ÎetBSD RAIDframe
Table of Contents
17.1. RAIDframe Introduction
17.1.1. About RAIDframe
17.1.2. A warning about Data Integrity, Backups, and High Availability
17.1.3. Getting Help
17.2. Setup RAIDframe Support
17.2.1. Kernel Support
17.2.2. Power Redundancy and Disk Caching
17.3. Example: RAID-1 Root Disk
17.3.1. Pseudo-Process Outline
17.3.2. Hardware Review
17.3.3. Initial Install on Disk0/wd0
17.3.4. Preparing Disk1/wd1
17.3.5. Initializing the RAID Device
17.3.6. Setting up Filesystems
17.3.7. Migrating System to RAID
17.3.8. The first boot with RAID
17.3.9. Adding Disk0/wd0 to RAID
17.3.10. Testing Boot Blocks
17.1. ÒAIDframe Introduction
17.1.1. Ábout RAIDframe
NetBSD uses the CMU RAIDframe software for its RAID subsystem. NetBSD is the
primary platform for RAIDframe development. RAIDframe can also be found in
OpenBSD and older versions of FreeBSD. NetBSD also has another in-kernel RAID
level 0 system in its ccd(4) subsystem (see Chapter6, Concatenated Disk
Device (CCD) configuration). You should possess some basic knowledge about RAID
concepts and terminology before continuing. You should also be at least
familiar with the different levels of RAID - Adaptec provides an excellent
reference, and the raid(4) manpage contains a short overview too.
17.1.2. Á warning about Data Integrity, Backups, and High Availability
RAIDframe is a Software RAID implementation, as opposed to Hardware RAID. As
such, it does not need special disk controllers supported by NetBSD. System
administrators should give a great deal of consideration to whether software
RAID or hardware RAID is more appropriate for their "Mission Critical"
applications. For some projects you might consider the use of many of the
hardware RAID devices supported by NetBSD. It is truly at your discretion what
type of RAID you use, but it is recommend that you consider factors such as:
manageability, commercial vendor support, load-balancing and failover, etc.
Depending on the RAID level used, RAIDframe does provide redundancy in the
event of a hardware failure. However, it is not a replacement for reliable
backups! Software and user-error can still cause data loss. RAIDframe may be
used as a mechanism for facilitating backups in systems without backup
hardware, but this is not an ideal configuration. Finally, with regard to "high
availability", RAID is only a very small component to ensuring data
availability.
Once more for good measure: Back up your data!
17.1.3. Çetting Help
If you encounter problems using RAIDframe, you have several options for
obtaining help.
1. Read the RAIDframe man pages: raid(4) and raidctl(8) thoroughly.
2. Search the mailing list archives. Unfortunately, there is no NetBSD list
dedicated to RAIDframe support. Depending on the nature of the problem,
posts tend to end up in a variety of lists. At a very minimum, search
netbsd-users@NetBSD.org, current-users@NetBSD.org. Also search the list for
the NetBSD platform on which you are using RAIDframe: port-${ARCH}
@NetBSD.org.
3. Search the Problem Report database.
4. If your problem persists: Post to the mailing list most appropriate
(judgment call). Collect as much verbosely detailed information as possible
before posting: Include your dmesg(8) output from /var/run/dmesg.boot, your
kernel config(5) , your /etc/raid[0-9].conf, any relevant errors on /dev/
console, /var/log/messages, or to stdout/stderr of raidctl(8). The output
of raidctl -s (if available) will be useful as well. Also include details
on the troubleshooting steps you've taken thus far, exactly when the
problem started, and any notes on recent changes that may have prompted the
problem to develop. Remember to be patient when waiting for a response.
17.2. Óetup RAIDframe Support
The use of RAID will require software and hardware configuration changes.
17.2.1. Ëernel Support
The GENERIC kernel already has support for RAIDframe. If you have built a
custom kernel for your environment the kernel configuration must have the
following options:
pseudo-device raid 8 # RAIDframe disk driver
options RAID_AUTOCONFIG # auto-configuration of RAID components
The RAID support must be detected by the NetBSD kernel, which can be checked by
looking at the output of the dmesg(8) command.
# dmesg|grep -i raid
Kernelized RAIDframe activated
Historically, the kernel must also contain static mappings between bus
addresses and device nodes in /dev. This used to ensure consistency of devices
within RAID sets in the event of a device failure after reboot. Since NetBSD
1.6, however, using the auto-configuration features of RAIDframe has been
recommended over statically mapping devices. The auto-configuration features
allow drives to move around on the system, and RAIDframe will automatically
determine which components belong to which RAID sets.
17.2.2. Ðower Redundancy and Disk Caching
If your system has an Uninterruptible Power Supply (UPS), and/or if your system
has redundant power supplies, you should consider enabling the read and write
caches on your drives. On systems with redundant power, this will improve drive
performance. On systems without redundant power, the write cache could endanger
the integrity of RAID data in the event of a power loss.
The dkctl(8) utility can be used for this on all kinds of disks that support
the operation (SCSI, EIDE, SATA, ...):
# dkctl wd0 getcache
/dev/rwd0d: read cache enabled
/dev/rwd0d: read cache enable is not changeable
/dev/rwd0d: write cache enable is changeable
/dev/rwd0d: cache parameters are not savable
# dkctl wd0 setcache rw
# dkctl wd0 getcache
/dev/rwd0d: read cache enabled
/dev/rwd0d: write-back cache enabled
/dev/rwd0d: read cache enable is not changeable
/dev/rwd0d: write cache enable is changeable
/dev/rwd0d: cache parameters are not savable
17.3. Åxample: RAID-1 Root Disk
This example explains how to setup RAID-1 root disk. With RAID-1 components are
mirrored and therefore the server can be fully functional in the event of a
single component failure. The goal is to provide a level of redundancy that
will allow the system to encounter a component failure on either component disk
in the RAID and:
* Continue normal operations until a maintenance window can be scheduled.
* Or, in the unlikely event that the component failure causes a system
reboot, be able to quickly reconfigure the system to boot from the
remaining component (platform dependent).
Figure7.1. ÒAID-1 Disk Logical Layout
RAID-1 Disk Logical Layout
Because RAID-1 provides both redundancy and performance improvements, its most
practical application is on critical "system" partitions such as /, /usr, /var,
swap, etc., where read operations are more frequent than write operations. For
other file systems, such as /home or /var/{application}, other RAID levels
might be considered (see the references above). If one were simply creating a
generic RAID-1 volume for a non-root file system, the cookie-cutter examples
from the man page could be followed, but because the root volume must be
bootable, certain special steps must be taken during initial setup.
Note
This example will outline a process that differs only slightly between the x86
and sparc64 platforms. In an attempt to reduce excessive duplication of
content, where differences do exist and are cosmetic in nature, they will be
pointed out using a section such as this. If the process is drastically
different, the process will branch into separate, platform dependent steps.
17.3.1. Ðseudo-Process Outline
Although a much more refined process could be developed using a custom copy of
NetBSD installed on custom-developed removable media, presently the NetBSD
install media lacks RAIDframe tools and support, so the following pseudo
process has become the de facto standard for setting up RAID-1 Root.
1. Install a stock NetBSD onto Disk0 of your system.
Figure7.2. Ðerform generic install onto Disk0/wd0
Perform generic install onto Disk0/wd0
2. Use the installed system on Disk0/wd0 to setup a RAID Set composed of Disk1
/wd1 only.
Figure7.3. Óetup RAID Set
Setup RAID Set
3. Reboot the system off the Disk1/wd1 with the newly created RAID volume.
Figure7.4. Òeboot using Disk1/wd1 of RAID
Reboot using Disk1/wd1 of RAID
4. Add / re-sync Disk0/wd0 back into the RAID set.
Figure7.5. Íirror Disk1/wd1 back to Disk0/wd0
Mirror Disk1/wd1 back to Disk0/wd0
17.3.2. Èardware Review
At present, the alpha, amd64, i386, pmax, sparc, sparc64, and vax NetBSD
platforms support booting from RAID-1. Booting is not supported from any other
RAID level. Booting from a RAID set is accomplished by teaching the 1st stage
boot loader to understand both 4.2BSD/FFS and RAID partitions. The 1st boot
block code only needs to know enough about the disk partitions and file systems
to be able to read the 2nd stage boot blocks. Therefore, at any time, the
system's BIOS / firmware must be able to read a drive with 1st stage boot
blocks installed. On the x86 platform, configuring this is entirely dependent
on the vendor of the controller card / host bus adapter to which your disks are
connected. On sparc64 this is controlled by the IEEE 1275 Sun OpenBoot
Firmware.
This article assumes two identical IDE disks (/dev/wd{0,1}) which we are going
to mirror (RAID-1). These disks are identified as:
# grep ^wd /var/run/dmesg.boot
wd0 at atabus0 drive 0: <WDC WD100BB-75CLB0>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 9541 MB, 19386 cyl, 16 head, 63 sec, 512 bytes/sect x 19541088 sectors
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd0(piixide0:0:0): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data transfers)
wd1 at atabus1 drive 0: <WDC WD100BB-75CLB0>
wd1: drive supports 16-sector PIO transfers, LBA addressing
wd1: 9541 MB, 19386 cyl, 16 head, 63 sec, 512 bytes/sect x 19541088 sectors
wd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd1(piixide0:1:0): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data transfers)
Note
If you are using SCSI, replace /dev/{,r}wd{0,1} with /dev/{,r}sd{0,1}
In this example, both disks are jumpered as Master on separate channels on the
same controller. You would never want to have both disks on the same bus on the
same controller; this creates a single point of failure. Ideally you would have
the disks on separate channels on separate controllers. Some SCSI controllers
have multiple channels on the same controller, however, a SCSI bus reset on one
channel could adversely affect the other channel if the ASIC/IC becomes
overloaded. The trade-off with two controllers is that twice the bandwidth is
used on the system bus. For purposes of simplification, this example shows two
disks on different channels on the same controller.
Note
RAIDframe requires that all components be of the same size. Actually, it will
use the lowest common denominator among components of dissimilar sizes. For
purposes of illustration, the example uses two disks of identical geometries.
Also, consider the availability of replacement disks if a component suffers a
critical hardware failure.
Tip
Two disks of identical vendor model numbers could have different geometries if
the drive possesses "grown defects". Use a low-level program to examine the
grown defects table of the disk. These disks are obviously suboptimal
candidates for use in RAID and should be avoided.
17.3.3. Énitial Install on Disk0/wd0
Perform a very generic installation onto your Disk0/wd0. Follow the INSTALL
instructions for your platform. Install all the sets but do not bother
customizing anything other than the kernel as it will be overwritten. See also
Chapter, Installing NetBSD: Preliminary considerations and preparations.
Tip
On x86, during the sysinst install, when prompted if you want to "use the
entire disk for NetBSD", answer "yes".
Once the installation is complete, you should examine the disklabel(8) and
fdisk(8) / sunlabel(8) outputs on the system:
# df
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/wd0a 9487886 502132 8511360 5% /
On x86:
# disklabel -r wd0
type: unknown
disk: Disk00
label:
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 19386
total sectors: 19541088
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
16 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 19276992 63 4.2BSD 1024 8192 46568 # (Cyl. 0* - 19124*)
b: 264033 19277055 swap # (Cyl. 19124* - 19385)
c: 19541025 63 unused 0 0 # (Cyl. 0* - 19385)
d: 19541088 0 unused 0 0 # (Cyl. 0 - 19385)
# fdisk /dev/rwd0d
Disk: /dev/rwd0d
NetBSD disklabel disk geometry:
cylinders: 19386, heads: 16, sectors/track: 63 (1008 sectors/cylinder)
total sectors: 19541088
BIOS disk geometry:
cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 19541088
Partition table:
0: NetBSD (sysid 169)
start 63, size 19541025 (9542 MB, Cyls 0-1216/96/1), Active
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector disabled.
First active partition: 0
On Sparc64 the command / output differs slightly:
# disklabel -r wd0
type: unknown
disk: Disk0
[...snip...]
8 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 19278000 0 4.2BSD 1024 8192 46568 # (Cyl. 0 - 19124)
b: 263088 19278000 swap # (Cyl. 19125 - 19385)
c: 19541088 0 unused 0 0 # (Cyl. 0 - 19385)
# sunlabel /dev/rwd0c
sunlabel> P
a: start cyl = 0, size = 19278000 (19125/0/0 - 9413.09Mb)
b: start cyl = 19125, size = 263088 (261/0/0 - 128.461Mb)
c: start cyl = 0, size = 19541088 (19386/0/0 - 9541.55Mb)
17.3.4. Ðreparing Disk1/wd1
Once you have a stock install of NetBSD on Disk0/wd0, you are ready to begin.
Disk1/wd1 will be visible and unused by the system. To setup Disk1/wd1, you
will use disklabel(8) to allocate the entire second disk to the RAID-1 set.
Tip
The best way to ensure that Disk1/wd1 is completely empty is to 'zero' out the
first few sectors of the disk with dd(1) . This will erase the MBR (x86) or Sun
disk label (sparc64), as well as the NetBSD disk label. If you make a mistake
at any point during the RAID setup process, you can always refer to this
process to restore the disk to an empty state.
Note
On sparc64, use /dev/rwd1c instead of /dev/rwd1d!
# dd if=/dev/zero of=/dev/rwd1d bs=8k count=1
1+0 records in
1+0 records out
8192 bytes transferred in 0.003 secs (2730666 bytes/sec)
Once this is complete, on x86, verify that both the MBR and NetBSD disk labels
are gone. On sparc64, verify that the Sun Disk label is gone as well.
On x86:
# fdisk /dev/rwd1d
fdisk: primary partition table invalid, no magic in sector 0
Disk: /dev/rwd1d
NetBSD disklabel disk geometry:
cylinders: 19386, heads: 16, sectors/track: 63 (1008 sectors/cylinder)
total sectors: 19541088
BIOS disk geometry:
cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 19541088
Partition table:
0: <UNUSED>
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector disabled.
# disklabel -r wd1
[...snip...]
16 partitions:
# size offset fstype [fsize bsize cpg/sgs]
c: 19541025 63 unused 0 0 # (Cyl. 0* - 19385)
d: 19541088 0 unused 0 0 # (Cyl. 0 - 19385)
On sparc64:
# sunlabel /dev/rwd1c
sunlabel: bogus label on `/dev/wd1c' (bad magic number)
# disklabel -r wd1
[...snip...]
3 partitions:
# size offset fstype [fsize bsize cpg/sgs]
c: 19541088 0 unused 0 0 # (Cyl. 0 - 19385)
disklabel: boot block size 0
disklabel: super block size 0
Now that you are certain the second disk is empty, on x86 you must establish
the MBR on the second disk using the values obtained from Disk0/wd0 above. We
must remember to mark the NetBSD partition active or the system will not boot.
You must also create a NetBSD disklabel on Disk1/wd1 that will enable a RAID
volume to exist upon it. On sparc64, you will need to simply disklabel(8) the
second disk which will write the proper Sun Disk Label.
Tip
disklabel(8) will use your shell' s environment variable $EDITOR variable to
edit the disklabel. The default is vi(1)
On x86:
# fdisk -0ua /dev/rwd1d
fdisk: primary partition table invalid, no magic in sector 0
Disk: /dev/rwd1d
NetBSD disklabel disk geometry:
cylinders: 19386, heads: 16, sectors/track: 63 (1008 sectors/cylinder)
total sectors: 19541088
BIOS disk geometry:
cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 19541088
Do you want to change our idea of what BIOS thinks? [n]
Partition 0:
<UNUSED>
The data for partition 0 is:
<UNUSED>
sysid: [0..255 default: 169]
start: [0..1216cyl default: 63, 0cyl, 0MB]
size: [0..1216cyl default: 19541025, 1216cyl, 9542MB]
bootmenu: []
Do you want to change the active partition? [n] y
Choosing 4 will make no partition active.
active partition: [0..4 default: 0] 0
Are you happy with this choice? [n] y
We haven't written the MBR back to disk yet. This is your last chance.
Partition table:
0: NetBSD (sysid 169)
start 63, size 19541025 (9542 MB, Cyls 0-1216/96/1), Active
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector disabled.
Should we write new partition table? [n] y
# disklabel -r -e -I wd1
type: unknown
disk: Disk1
label:
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 19386
total sectors: 19541088
[...snip...]
16 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 19541025 63 RAID # (Cyl. 0*-19385)
c: 19541025 63 unused 0 0 # (Cyl. 0*-19385)
d: 19541088 0 unused 0 0 # (Cyl. 0 -19385)
On sparc64:
# disklabel -r -e -I wd1
type: unknown
disk: Disk1
label:
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 19386
total sectors: 19541088
[...snip...]
3 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 19541088 0 RAID # (Cyl. 0 - 19385)
c: 19541088 0 unused 0 0 # (Cyl. 0 - 19385)
# sunlabel /dev/rwd1c
sunlabel> P
a: start cyl = 0, size = 19541088 (19386/0/0 - 9541.55Mb)
c: start cyl = 0, size = 19541088 (19386/0/0 - 9541.55Mb)
Note
On x86, the c: and d: slices are reserved. c: represents the NetBSD portion of
the disk. d: represents the entire disk. Because we want to allocate the entire
NetBSD MBR partition to RAID, and because a: resides within the bounds of c:,
the a: and c: slices have same size and offset values. The offset must start at
a track boundary (an increment of sectors matching the sectors/track value in
the disk label). On sparc64 however, c: represents the entire NetBSD partition
in the Sun disk label and d: is not reserved. Also note that sparc64's c: and
a: require no offset from the beginning of the disk, however if they should
need to be, the offset must start at a cylinder boundary (an increment of
sectors matching the sectors/cylinder value).
17.3.5. Énitializing the RAID Device
Next we create the configuration file for the RAID set / volume. Traditionally,
RAIDframe configuration files belong in /etc and would be read and initialized
at boot time, however, because we are creating a bootable RAID volume, the
configuration data will actually be written into the RAID volume using the
"auto-configure" feature. Therefore, files are needed only during the initial
setup and should not reside in /etc.
# vi /var/tmp/raid0.conf
START array
1 2 0
START disks
absent
/dev/wd1a
START layout
128 1 1 1
START queue
fifo 100
Note that absent means a non-existing disk. This will allow us to establish the
RAID volume with a bogus component that we will substitute for Disk0/wd0 at a
later time.
Next we configure the RAID device and initialize the serial number to something
unique. In this example we use a "YYYYMMDDRevision" scheme. The format you
choose is entirely at your discretion, however the scheme you choose should
ensure that no two RAID sets use the same serial number at the same time.
After that we initialize the RAID set for the first time, safely ignoring the
errors regarding the bogus component.
# raidctl -v -C /var/tmp/raid0.conf raid0
Ignoring missing component at column 0
raid0: Component absent being configured at col: 0
Column: 0 Num Columns: 0
Version: 0 Serial Number: 0 Mod Counter: 0
Clean: No Status: 0
Number of columns do not match for: absent
absent is not clean!
raid0: Component /dev/wd1a being configured at col: 1
Column: 0 Num Columns: 0
Version: 0 Serial Number: 0 Mod Counter: 0
Clean: No Status: 0
Column out of alignment for: /dev/wd1a
Number of columns do not match for: /dev/wd1a
/dev/wd1a is not clean!
raid0: There were fatal errors
raid0: Fatal errors being ignored.
raid0: RAID Level 1
raid0: Components: component0[**FAILED**] /dev/wd1a
raid0: Total Sectors: 19540864 (9541 MB)
# raidctl -v -I 2009122601 raid0
# raidctl -v -i raid0
Initiating re-write of parity
raid0: Error re-writing parity!
Parity Re-write status:
# tail -1 /var/log/messages
Dec 26 00:00:30 /netbsd: raid0: Error re-writing parity!
# raidctl -v -s raid0
Components:
component0: failed
/dev/wd1a: optimal
No spares.
component0 status is: failed. Skipping label.
Component label for /dev/wd1a:
Row: 0, Column: 1, Num Rows: 1, Num Columns: 2
Version: 2, Serial Number: 2009122601, Mod Counter: 7
Clean: No, Status: 0
sectPerSU: 128, SUsPerPU: 1, SUsPerRU: 1
Queue size: 100, blocksize: 512, numBlocks: 19540864
RAID Level: 1
Autoconfig: No
Root partition: No
Last configured as: raid0
Parity status: DIRTY
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
17.3.6. Óetting up Filesystems
Caution
The root filesystem must begin at sector 0 of the RAID device. Else, the
primary boot loader will be unable to find the secondary boot loader.
The RAID device is now configured and available. The RAID device is a pseudo
disk-device. It will be created with a default disk label. You must now
determine the proper sizes for disklabel slices for your production
environment. For purposes of simplification in this example, our system will
have 8.5 gigabytes dedicated to / as /dev/raid0a and the rest allocated to swap
as /dev/raid0b.
Caution
This is an unrealistic disk layout for a production server; the NetBSD Guide
can expand on proper partitioning technique. See Chapter, Installing NetBSD:
Preliminary considerations and preparations
Note
Note that 1 GB is 2*1024*1024=2097152 blocks (1 block is 512 bytes, or 0.5
kilobytes). Despite what the underlying hardware composing a RAID set is, the
RAID pseudo disk will always have 512 bytes/sector.
Note
In our example, the space allocated to the underlying a: slice composing the
RAID set differed between x86 and sparc64, therefore the total sectors of the
RAID volumes differs:
On x86:
# disklabel -r -e -I raid0
type: RAID
disk: raid
label: fictitious
flags:
bytes/sector: 512
sectors/track: 128
tracks/cylinder: 8
sectors/cylinder: 1024
cylinders: 19082
total sectors: 19540864
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
# size offset fstype [fsize bsize cpg/sgs]
a: 19015680 0 4.2BSD 0 0 0 # (Cyl. 0 - 18569)
b: 525184 19015680 swap # (Cyl. 18570 - 19082*)
d: 19540864 0 unused 0 0 # (Cyl. 0 - 19082*)
On sparc64:
# disklabel -r -e -I raid0
[...snip...]
total sectors: 19539968
[...snip...]
3 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 19251200 0 4.2BSD 0 0 0 # (Cyl. 0 - 18799)
b: 288768 19251200 swap # (Cyl. 18800 - 19081)
c: 19539968 0 unused 0 0 # (Cyl. 0 - 19081)
Next, format the newly created / partition as a 4.2BSD FFSv1 File System:
# newfs -O 1 /dev/rraid0a
/dev/rraid0a: 9285.0MB (19015680 sectors) block size 16384, fragment size 2048
using 51 cylinder groups of 182.06MB, 11652 blks, 23040 inodes.
super-block backups (for fsck -b #) at:
32, 372896, 745760, 1118624, 1491488, 1864352, 2237216, 2610080, 2982944,
...............................................................................
# fsck -fy /dev/rraid0a
** /dev/rraid0a
** File system is already clean
** Last Mounted on
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
1 files, 1 used, 4679654 free (14 frags, 584955 blocks, 0.0% fragmentation)
17.3.7. Íigrating System to RAID
The new RAID filesystems are now ready for use. We mount them under /mnt and
copy all files from the old system. This can be done using dump(8) or pax(1).
# mount /dev/raid0a /mnt
# df -h /mnt
Filesystem Size Used Avail %Cap Mounted on
/dev/raid0a 8.9G 2.0K 8.5G 0% /mnt
# cd /; pax -v -X -rw -pe . /mnt
[...snip...]
The NetBSD install now exists on the RAID filesystem. We need to fix the
mount-points in the new copy of /etc/fstab or the system will not come up
correctly. Replace instances of wd0 with raid0.
The swap should be unconfigured upon shutdown to avoid parity errors on the
RAID device. This can be done with a simple, one-line setting in /etc/rc.conf.
# vi /mnt/etc/rc.conf
swapoff=YES
Next the boot loader must be installed on Disk1/wd1. Failure to install the
loader on Disk1/wd1 will render the system un-bootable if Disk0/wd0 fails
making the RAID-1 pointless.
Tip
Because the BIOS/CMOS menus in many x86 based systems are misleading with
regard to device boot order. I highly recommend utilizing the "-o timeout=X"
option supported by the x86 1st stage boot loader. Setup unique values for each
disk as a point of reference so that you can easily determine from which disk
the system is booting.
Caution
Although it may seem logical to install the 1st stage boot block into /dev/rwd1
{c,d} with installboot(8) , this is no longer the case since NetBSD 1.6.x. If
you make this mistake, the boot sector will become irrecoverably damaged and
you will need to start the process over again.
On x86, install the boot loader into /dev/rwd1a :
# /usr/sbin/installboot -o timeout=30 -v /dev/rwd1a /usr/mdec/bootxx_ffsv2
File system: /dev/rwd1a
Primary bootstrap: /usr/mdec/bootxx_ffsv2
Ignoring PBR with invalid magic in sector 0 of `/dev/rwd1a'
Boot options: timeout 30, flags 0, speed 9600, ioaddr 0, console pc
Note
As of NetBSD 6.x, the default filesystem type on x86 platforms is FFSv2 instead
of FFSv1. Make sure you use the correct 1st stage boot block file /usr/mdec/
bootxx_ffsv{1,2} when running the installboot(8) command.
To find out which filesystem type is currently in use, the command file(1) or
dumpfs(8) can be used:
# /usr/bin/file -s /dev/rwd1a
/usr/bin/file -s /dev/rwd1a
/dev/rwd1a: Unix Fast File system [v2] (little-endian), last mounted on ...
or
# /usr/sbin/dumpfs -s /dev/rwd1a
file system: /dev/rwd1a
format FFSv2
endian little-endian
...
On sparc64, install the boot loader into /dev/rwd1a as well, however the "-o"
flag is unsupported (and un-needed thanks to OpenBoot):
# /usr/sbin/installboot -v /dev/rwd1a /usr/mdec/bootblk
File system: /dev/rwd1a
Primary bootstrap: /usr/mdec/bootblk
Bootstrap start sector: 1
Bootstrap byte count: 5140
Writing bootstrap
Finally the RAID set must be made auto-configurable and the system should be
rebooted. After the reboot everything is mounted from the RAID devices.
# raidctl -v -A root raid0
raid0: Autoconfigure: Yes
raid0: Root: Yes
# tail -2 /var/log/messages
raid0: New autoconfig value is: 1
raid0: New rootpartition value is: 1
# raidctl -v -s raid0
[...snip...]
Autoconfig: Yes
Root partition: Yes
Last configured as: raid0
[...snip...]
# shutdown -r now
Warning
Always use shutdown(8) when shutting down. Never simply use reboot(8). reboot
(8) will not properly run shutdown RC scripts and will not safely disable
swap. This will cause dirty parity at every reboot.
17.3.8. Ôhe first boot with RAID
At this point, temporarily configure your system to boot Disk1/wd1. See notes
in Section7.3.10, "Testing Boot Blocks" for details on this process. The
system should boot now and all filesystems should be on the RAID devices. The
RAID will be functional with a single component, however the set is not fully
functional because the bogus drive (wd9) has failed.
# egrep -i "raid|root" /var/run/dmesg.boot
raid0: RAID Level 1
raid0: Components: component0[**FAILED**] /dev/wd1a
raid0: Total Sectors: 19540864 (9541 MB)
boot device: raid0
root on raid0a dumps on raid0b
root file system type: ffs
# df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/raid0a 8.9G 196M 8.3G 2% /
kernfs 1.0K 1.0K 0B 100% /kern
# swapctl -l
Device 1K-blocks Used Avail Capacity Priority
/dev/raid0b 262592 0 262592 0% 0
# raidctl -s raid0
Components:
component0: failed
/dev/wd1a: optimal
No spares.
component0 status is: failed. Skipping label.
Component label for /dev/wd1a:
Row: 0, Column: 1, Num Rows: 1, Num Columns: 2
Version: 2, Serial Number: 2009122601, Mod Counter: 65
Clean: No, Status: 0
sectPerSU: 128, SUsPerPU: 1, SUsPerRU: 1
Queue size: 100, blocksize: 512, numBlocks: 19540864
RAID Level: 1
Autoconfig: Yes
Root partition: Yes
Last configured as: raid0
Parity status: DIRTY
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
17.3.9. Ádding Disk0/wd0 to RAID
We will now add Disk0/wd0 as a component of the RAID. This will destroy the
original file system structure. On x86, the MBR disklabel will be unaffected
(remember we copied wd0's label to wd1 anyway) , therefore there is no need to
"zero" Disk0/wd0. However, we need to relabel Disk0/wd0 to have an identical
NetBSD disklabel layout as Disk1/wd1. Then we add Disk0/wd0 as "hot-spare" to
the RAID set and initiate the parity reconstruction for all RAID devices,
effectively bringing Disk0/wd0 into the RAID-1 set and "synching up" both
disks.
# disklabel -r wd1 > /tmp/disklabel.wd1
# disklabel -R -r wd0 /tmp/disklabel.wd1
As a last-minute sanity check, you might want to use diff(1) to ensure that the
disklabels of Disk0/wd0 match Disk1/wd1. You should also backup these files for
reference in the event of an emergency.
# disklabel -r wd0 > /tmp/disklabel.wd0
# disklabel -r wd1 > /tmp/disklabel.wd1
# diff /tmp/disklabel.wd0 /tmp/disklabel.wd1
# fdisk /dev/rwd0 > /tmp/fdisk.wd0
# fdisk /dev/rwd1 > /tmp/fdisk.wd1
# diff /tmp/fdisk.wd0 /tmp/fdisk.wd1
# mkdir /root/RFbackup
# cp -p /tmp/{disklabel,fdisk}* /root/RFbackup
Once you are certain, add Disk0/wd0 as a spare component, and start
reconstruction:
# raidctl -v -a /dev/wd0a raid0
/netbsd: Warning: truncating spare disk /dev/wd0a to 241254528 blocks
# raidctl -v -s raid0
Components:
component0: failed
/dev/wd1a: optimal
Spares:
/dev/wd0a: spare
[...snip...]
# raidctl -F component0 raid0
RECON: initiating reconstruction on col 0 -> spare at col 2
11% |**** | ETA: 04:26 \
Depending on the speed of your hardware, the reconstruction time will vary. You
may wish to watch it on another terminal:
# raidctl -S raid0
Reconstruction is 0% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
Reconstruction status:
17% |****** | ETA: 03:08 -
After reconstruction, both disks should be "optimal".
# tail -f /var/log/messages
raid0: Reconstruction of disk at col 0 completed
raid0: Recon time was 1290.625033 seconds, accumulated XOR time was 0 us (0.000000)
raid0: (start time 1093407069 sec 145393 usec, end time 1093408359 sec 770426 usec)
raid0: Total head-sep stall count was 0
raid0: 305318 recon event waits, 1 recon delays
raid0: 1093407069060000 max exec ticks
# raidctl -v -s raid0
Components:
component0: spared
/dev/wd1a: optimal
Spares:
/dev/wd0a: used_spare
[...snip...]
When the reconstruction is finished we need to install the boot loader on the
Disk0/wd0. On x86, install the boot loader into /dev/rwd0a:
# /usr/sbin/installboot -o timeout=15 -v /dev/rwd0a /usr/mdec/bootxx_ffsv2
File system: /dev/rwd0a
Primary bootstrap: /usr/mdec/bootxx_ffsv2
Boot options: timeout 15, flags 0, speed 9600, ioaddr 0, console pc
On sparc64:
# /usr/sbin/installboot -v /dev/rwd0a /usr/mdec/bootblk
File system: /dev/rwd0a
Primary bootstrap: /usr/mdec/bootblk
Bootstrap start sector: 1
Bootstrap byte count: 5140
Writing bootstrap
And finally, reboot the machine one last time before proceeding. This is
required to migrate Disk0/wd0 from status "used_spare" as "Component0" to state
"optimal". Refer to notes in the next section regarding verification of clean
parity after each reboot.
# shutdown -r now
17.3.10. Ôesting Boot Blocks
At this point, you need to ensure that your system's hardware can properly boot
using the boot blocks on either disk. On x86, this is a hardware-dependent
process that may be done via your motherboard CMOS/BIOS menu or your controller
card's configuration menu.
On x86, use the menu system on your machine to set the boot device order /
priority to Disk1/wd1 before Disk0/wd0. The examples here depict a generic
Award BIOS.
Figure7.6. Áward BIOS i386 Boot Disk1/wd1
Award BIOS i386 Boot Disk1/wd1
Save changes and exit.
>> NetBSD/i386 BIOS Boot, Revision 5.2 (from NetBSD 5.0.2)
>> (builds@b7, Sun Feb 7 00:30:50 UTC 2010)
>> Memory: 639/130048 k
Press return to boot now, any other key for boot menu
booting hd0a:netbsd - starting in 30
You can determine that the BIOS is reading Disk1/wd1 because the timeout of the
boot loader is 30 seconds instead of 15. After the reboot, re-enter the BIOS
and configure the drive boot order back to the default:
Figure7.7. Áward BIOS i386 Boot Disk0/wd0
Award BIOS i386 Boot Disk0/wd0
Save changes and exit.
>> NetBSD/x86 BIOS Boot, Revision 5.9 (from NetBSD 6.0)
>> Memory: 640/261120 k
1. Boot normally
2. Boot single use
3. Disable ACPI
4. Disable ACPI and SMP
5. Drop to boot prompt
Choose an option; RETURN for default; SPACE to stop countdown.Option 1 will be chosen in 0 seconds.
Notice how your custom kernel detects controller/bus/drive assignments
independent of what the BIOS assigns as the boot disk. This is the expected
behavior.
On sparc64, use the Sun OpenBoot devalias to confirm that both disks are
bootable:
Sun Ultra 5/10 UPA/PCI (UltraSPARC-IIi 400MHz), No Keyboard
OpenBoot 3.15, 128 MB memory installed, Serial #nnnnnnnn.
Ethernet address 8:0:20:a5:d1:3b, Host ID: nnnnnnnn.
ok devalias
[...snip...]
cdrom /pci@1f,0/pci@1,1/ide@3/cdrom@2,0:f
disk /pci@1f,0/pci@1,1/ide@3/disk@0,0
disk3 /pci@1f,0/pci@1,1/ide@3/disk@3,0
disk2 /pci@1f,0/pci@1,1/ide@3/disk@2,0
disk1 /pci@1f,0/pci@1,1/ide@3/disk@1,0
disk0 /pci@1f,0/pci@1,1/ide@3/disk@0,0
[...snip...]
ok boot disk0 netbsd
Initializing Memory [...]
Boot device /pci/pci/ide@3/disk@0,0 File and args: netbsd
NetBSD IEEE 1275 Bootblock
>> NetBSD/sparc64 OpenFirmware Boot, Revision 1.13
>> (builds@b7.netbsd.org, Wed Jul 29 23:43:42 UTC 2009)
loadfile: reading header
elf64_exec: Booting [...]
symbols @ [....]
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
2006, 2007, 2008, 2009
The NetBSD Foundation, Inc. All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
The Regents of the University of California. All rights reserved.
[...snip...]
And the second disk:
ok boot disk2 netbsd
Initializing Memory [...]
Boot device /pci/pci/ide@3/disk@2,0: File and args:netbsd
NetBSD IEEE 1275 Bootblock
>> NetBSD/sparc64 OpenFirmware Boot, Revision 1.13
>> (builds@b7.netbsd.org, Wed Jul 29 23:43:42 UTC 2009)
loadfile: reading header
elf64_exec: Booting [...]
symbols @ [....]
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
2006, 2007, 2008, 2009
The NetBSD Foundation, Inc. All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
The Regents of the University of California. All rights reserved.
[...snip...]
At each boot, the following should appear in the NetBSD kernel dmesg(8) :
Kernelized RAIDframe activated
raid0: RAID Level 1
raid0: Components: /dev/wd0a /dev/wd1a
raid0: Total Sectors: 19540864 (9541 MB)
boot device: raid0
root on raid0a dumps on raid0b
root file system type: ffs
Once you are certain that both disks are bootable, verify the RAID parity is
clean after each reboot:
# raidctl -v -s raid0
Components:
/dev/wd0a: optimal
/dev/wd1a: optimal
No spares.
[...snip...]
Component label for /dev/wd0a:
Row: 0, Column: 0, Num Rows: 1, Num Columns: 2
Version: 2, Serial Number: 2009122601, Mod Counter: 67
Clean: No, Status: 0
sectPerSU: 128, SUsPerPU: 1, SUsPerRU: 1
Queue size: 100, blocksize: 512, numBlocks: 19540864
RAID Level: 1
Autoconfig: Yes
Root partition: Yes
Last configured as: raid0
Component label for /dev/wd1a:
Row: 0, Column: 1, Num Rows: 1, Num Columns: 2
Version: 2, Serial Number: 2009122601, Mod Counter: 67
Clean: No, Status: 0
sectPerSU: 128, SUsPerPU: 1, SUsPerRU: 1
Queue size: 100, blocksize: 512, numBlocks: 19540864
RAID Level: 1
Autoconfig: Yes
Root partition: Yes
Last configured as: raid0
Parity status: clean
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
Chapter8. ÎetBSD Logical Volume Manager (LVM) configuration
Table of Contents
18.1. Anatomy of NetBSD Logical Volume Manager
18.2. Install physical media
18.3. Configure Kernel Support
18.4. Disklabel each physical volume member of the LVM
18.5. Create Physical Volumes
18.6. Create Volume Group
18.7. Create Logical Volume
18.8. Example: LVM with Volume groups located on raid1
18.8.1. Loading Device-Mapper driver
18.8.2. Preparing raid1 installation
18.8.3. Creating PV, VG on raid disk
18.8.4. Creating LV's from VG located on raid disk
18.8.5. Integration of LV's in to the system
NetBSD LVM allows logical volume management on NetBSD systems, with a well
known user interface, which is the same as the Linux LVM2 tools.
NetBSD LVM is built on Linux lvm2tools and libdevmapper, together with a
BSD-licensed device-mapper kernel driver specially written for NetBSD.
The LVM driver allows the user to manage available disk space effectively and
efficiently. Disk space from several disks, and partitions, known as "Physical
Volumes", can be added to "Volume Groups", which is the pool of available disk
space for "Logical Partitions" aka Logical Volumes.
Logical Volumes can be grown and shrunk at will using the LVM utilities.
The basic building block is the Physical Volume. This is a disk, or a part of a
disk, which is used to store data.
Physical Volumes are aggregated together to make Volume Groups, or VGs.
Typically, Volume Groups are used to aggregate storage for the same functional
unit. Typical Volume Groups could thus be named "Audio", "Multimedia" or "
Documents". By segregating storage requirements in this functional way, the
same type of resilience and redundancy is applied to the whole of the
functional unit.
The steps required to setup a LVM are as follows:
1. Install physical media
2. Configure kernel support
3. Configure system, install tools
4. Optional step
Disklabel each volume member of the LVM
5. Initialize the LVM disk devices
6. Create a volume group from initialized disks
7. Create Logical volume from created Volume group
8. Create a filesystem on the new LV device
9. Mount the LV filesystem
This example features a LVM setup on NetBSD/i386.
18.1. Ánatomy of NetBSD Logical Volume Manager
Figure8.1. Ánatomy of Logical Volume Management
Anatomy of Logical Volume Management
1. Volume Group
The Volume Group is a disk space pool from which the user creates Logical
Volumes and to which Physical Volumes can be added. It is the basic
administration unit of the NetBSD LVM implementation.
2. Physical Volume
A physical volume is the basic unit in a LVM structure. Every PV consists
of small disk space chunks called Physical Extends. Every Volume Group must
have at least one PV. A PV can be created on hard disks or hard disk like
devices such as raid, ccd, or cgd device.
3. Logical Volume
The Logical Volume is a logical partition created from disk space assigned
to the Volume Group. LV can be newfsed and mounted as any other pseudo-disk
device. Lvm tools use functionality exported by the device-mapper driver in
the kernel to create the LV.
4. Physical Extents
Each physical volume is divided chunks of disk space. The default size is
4MB. Every LV size is rounded by PE size. The LV is created by mapping
Logical Extends in the LV to Physical extends in a Volume group.
5. Logical Extents
Each logical volume is split into chunks of disk space, known as logical
extents. The extent size is the same for all logical volumes in the volume
group.
6. Physical Extents mapping
Every LV consists of "LEs" mapped to "PEs" mapped by a target mapping.
Currently, the following mappings are defined.
+ Linear Mapping
will linearly assign range of PEs to LEs.
For example it can map 100 PEs from PV 1 to LV 1 and
another 100 PEs from PV 0.
+ Stripe Mapping
will interleave the chunks of the logical extents across a number of
physical volumes.
7. Snapshots
A facility provided by LVM is 'snapshots'. Whilst in standard NetBSD, the "
fss" driver can be used to provide filesystem snapshots at a filesystem
level, the snapshot facility in the LVM allows the administrator to create
a logical block device which presents an exact copy of a logical volume,
frozen at some point in time. This facility does require that the snapshot
be made at a time when the data on the logical volume is in a consistent
state.
Warning
Snapshot feature is not fully implemented in LVM in NetBSD and should not
be used in production.
18.2. Énstall physical media
This step is at your own discretion, depending on your platform and the
hardware at your disposal. LVM can be used with disklabel partitions or even
with standard partitions created with fdisk.
From my "dmesg":
Disk #1:
probe(esp0:0:0): max sync rate 10.00MB/s
sd0 at scsibus0 target 0 lun 0: <SEAGATE, ST32430N SUN2.1G, 0444> SCSI2 0/direct fixed
sd0: 2049 MB, 3992 cyl, 9 head, 116 sec, 512 bytes/sect x 4197405 sectors
Disk #2
probe(esp0:1:0): max sync rate 10.00MB/s
sd1 at scsibus0 target 1 lun 0: <SEAGATE, ST32430N SUN2.1G, 0444> SCSI2 0/direct fixed
sd1: 2049 MB, 3992 cyl, 9 head, 116 sec, 512 bytes/sect x 4197405 sectors
Disk #3
probe(esp0:2:0): max sync rate 10.00MB/s
sd2 at scsibus0 target 2 lun 0: <SEAGATE, ST11200N SUN1.05, 9500> SCSI2 0/direct fixed
sd2: 1005 MB, 1872 cyl, 15 head, 73 sec, 512 bytes/sect x 2059140 sectors
Disk #4
probe(esp0:3:0): max sync rate 10.00MB/s
sd3 at scsibus0 target 3 lun 0: <SEAGATE, ST11200N SUN1.05, 8808 > SCSI2 0
sd3: 1005 MB, 1872 cyl, 15 head, 73 sec, 512 bytes/sect x 2059140 sectors
18.3. Ãonfigure Kernel Support
The following kernel configuration directive is needed to provide LVM device
support. It is provided as a kernel module, so that no extra modifications need
be made to a standard NetBSD kernel.
pseudo-device dm
If you do not want to rebuild your kernel only because of LVM support you can
use dm kernel module. The devmapper kernel module can be loaded on your system.
To get the current status of modules in the kernel, the modstat is used:
vm1# modstat
NAME CLASS SOURCE REFS SIZE REQUIRES
cd9660 vfs filesys 0 21442 -
coredump misc filesys 1 2814 -
exec_elf32 misc filesys 0 6713 coredump
exec_script misc filesys 0 1091 -
ffs vfs boot 0 163040 -
kernfs vfs filesys 0 10201 -
ptyfs vfs filesys 0 7852 -
When the modload dm is issued, the dm kernel module will be loaded:
vm1# modstat
NAME CLASS SOURCE REFS SIZE REQUIRES
cd9660 vfs filesys 0 21442 -
coredump misc filesys 1 2814 -
dm misc filesys 0 14448 -
exec_elf32 misc filesys 0 6713 coredump
exec_script misc filesys 0 1091 -
ffs vfs boot 0 163040 -
kernfs vfs filesys 0 10201 -
ptyfs vfs filesys 0 7852 -
18.4. Äisklabel each physical volume member of the LVM
Each physical volume disk in LVM will need a special filesystem established. In
this example, I will need to disklabel:
/dev/rsd0d
/dev/rsd1d
/dev/rsd2d
/dev/rsd3d
It should be borne in mind that it is possible to use the NetBSD vnd driver to
make standard filesystem space appear in the system as a disk device.
Note
Always remember to disklabel the character device, not the block device, in /
dev/r{s,w}d*
Note
On all platforms except amd64 and i386 where the d partition is used for this,
the c slice is symbolic of the entire NetBSD partition and is reserved.
You will probably want to remove any pre-existing disklabels on the physical
volume disks in the LVM. This can be accomplished in one of two ways with the
dd(1) command:
# dd if=/dev/zero of=/dev/rsd0d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd1d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd2d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd3d bs=8k count=1
If your port uses a MBR (Master Boot Record) to partition the disks so that the
NetBSD partitions are only part of the overall disk, and other OSs like Windows
or Linux use other parts, you can void the MBR and all partitions on disk by
using the command:
# dd if=/dev/zero of=/dev/rsd0d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd1d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd2d bs=8k count=1
# dd if=/dev/zero of=/dev/rsd3d bs=8k count=1
This will make all data on the entire disk inaccessible. Note that the entire
disk is slice d on i386 (and some other ports), and c elsewhere (e.g. on
sparc). See the "kern.rawpartition" sysctl - "3" means "d", "2" means "c".
The default disklabel for the disk will look similar to this:
# disklabel -r sd0
[...snip...]
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 207
total sectors: 208896
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
4 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 208896 0 4.2BSD 0 0 0 # (Cyl. 0 - 207*)
d: 208896 0 unused 0 0 # (Cyl. 0 - 207*)
You will need to create one "slice" on the NetBSD partition of the disk that
consumes the entire partition. The slice must begin at least two sectors after
end of disklabel part of disk. On i386 it is sector "63". Therefore, the "size"
value should be "total sectors" minus 2x "sectors". Edit your disklabel
accordingly:
# disklabel -e sd0
Note
The offset of a slice of type "4.2BSD" must be a multiple of the "sectors"
value.
Note
Be sure to export EDITOR=[path to your favorite editor] before editing the
disklabels.
Note
The slice must be fstype 4.2BSD.
Because there will only be one slice on this partition, you can recycle the d
slice (normally reserved for symbolic uses). Change your disklabel to the
following:
3 partitions:
# size offset fstype [fsize bsize cpg]
d: 4197403 65 4.2BSD # (Cyl. 1 - 4020*)
Optionally you can setup a slice other than d to use, simply adjust accordingly
below:
3 partitions:
# size offset fstype [fsize bsize cpg]
a: 4197403 65 4.2BSD # (Cyl. 1 - 4020*)
c: 4197405 0 unused 1024 8192 # (Cyl. 0 - 4020*)
Be sure to write the label when you have completed. Disklabel will object to
your disklabel and prompt you to re-edit if it does not pass its sanity checks.
18.5. Ãreate Physical Volumes
Once all disks are properly labeled, you will need to create physical volume on
them. Every partition/disk added to LVM must have physical volume header on
start of it. All informations, like Volume group where Physical volume belongs
are stored in this header.
# lvm pvcreate /dev/rwd1[ad]
Status of physical volume can be viewed with pvdisplay command.
# lvm pvdisplay
18.6. Ãreate Volume Group
Once all disks are properly labeled with physical volume header, volume group
must be created from them. Volume Group is pool of PEs from which administrator
can create Logical Volumes "partitions".
# lvm vgcreate vg0 /dev/rwd1[ad]
* vg0 is name of Volume Group
* /dev/rwd1[ad] is Physical Volume
Volume group can be later extended/reduced with vgextend and vgreduce commands.
These commands adds physical volumes to VG.
# lvm vgextend vg0 /dev/rwd1[ad]
# lvm vgreduce vg0 /dev/rwd1[ad]
Status of Volume group can be viewed with vgdisplay command.
# lvm vgdisplay vg0
18.7. Ãreate Logical Volume
Once Volume Group was created administrator can create "logical partitions"
volumes.
# lvm lvcreate -L 20M -n lv1 vg0
* vg0 is name of Volume Group
* -L 20M is size of Logical Volume
* -n lv1 is name of Logical Volume
Logical Volume can be later extended/reduced with lvextend and lvreduce
commands.
# lvm lvextend -L+20M /dev/vg0/lv1
# lvm lvreduce -L-20M /dev/vg0/lv1
Note
To shrink the lv partition, you must first shrink the filesystem using
resize_ffs(8) (which as of NetBSD 9.0 does not support shrinking of FFSv2 yet).
Status of Logical Volume can be viewed with lvdisplay command.
# lvm lvdisplay lv0/lv1
After reboot all functional LV's in defined Volume group can be activated with
command
# lvm vgchange -a y
18.8. Åxample: LVM with Volume groups located on raid1
Motivation for using raid 1 disk as physical volume disk for Volume Group is
disk reliability. With PV on raid 1 disk it is possible to use Logical Volumes
even after disk failure.
18.8.1. Ìoading Device-Mapper driver
Before we can start work with the LVM tools. We have to be sure that NetBSD dm
driver was properly compiled into the kernel or loaded as a module. Easiest way
how to find if we have dm driver available is run modstat. For more information
see Configure Kernel Support chapter.
18.8.2. Ðreparing raid1 installation
Following example raid configuration defined in Raid 1 configuration user will
set up clean raid1 disk device. With 2 disks in a mirror mode.
Figure8.2. Åxample raid 1 configuration
# vi /var/tmp/raid0.conf
START array
1 2 0
START disks
/dev/wd2a
/dev/wd1a
START layout
128 1 1 1
START queue
fifo 100
# raidctl -v -C /var/tmp/raid0.conf raid0
raid0: Component /dev/wd1a being configured at col: 0
Column: 0 Num Columns: 0
Version: 0 Serial Number: 0 Mod Counter: 0
Clean: No Status: 0
Column out of alignment for: /dev/wd2a
Number of columns do not match for: /dev/wd2a
/dev/wd2a is not clean!
raid0: Component /dev/wd1a being configured at col: 1
Column: 0 Num Columns: 0
Version: 0 Serial Number: 0 Mod Counter: 0
Clean: No Status: 0
Column out of alignment for: /dev/wd1a
Number of columns do not match for: /dev/wd1a
/dev/wd1a is not clean!
raid0: There were fatal errors
raid0: Fatal errors being ignored.
raid0: RAID Level 1
raid0: Components: /dev/wd2a /dev/wd1a
raid0: Total Sectors: 19540864 (9541 MB)
# raidctl -v -I 2004082401 raid0
# raidctl -v -i raid0
Initiating re-write of parity
# tail -1 /var/log/messages
raid0: Error re-writing parity!
# raidctl -v -s raid0
Components:
/dev/wd2a: optimal
/dev/wd1a: optimal
No spares.
Component label for /dev/wd1a:
Row: 0, Column: 1, Num Rows: 1, Num Columns: 2
Version: 2, Serial Number: 2004082401, Mod Counter: 7
Clean: No, Status: 0
sectPerSU: 128, SUsPerPU: 1, SUsPerRU: 1
Queue size: 100, blocksize: 512, numBlocks: 19540864
RAID Level: 1
Autoconfig: No
Root partition: No
Last configured as: raid0
Parity status: DIRTY
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
Component label for /dev/wd2a:
Row: 0, Column: 1, Num Rows: 1, Num Columns: 2
Version: 2, Serial Number: 2004082401, Mod Counter: 7
Clean: No, Status: 0
sectPerSU: 128, SUsPerPU: 1, SUsPerRU: 1
Queue size: 100, blocksize: 512, numBlocks: 19540864
RAID Level: 1
Autoconfig: No
Root partition: No
Last configured as: raid0
Parity status: DIRTY
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
After setting up raid we need to create disklabel on raid disk.
On i386:
# disklabel -r -e -I raid0
type: RAID
disk: raid
label: fictitious
flags:
bytes/sector: 512
sectors/track: 128
tracks/cylinder: 8
sectors/cylinder: 1024
cylinders: 19082
total sectors: 19540864
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0 # microseconds
track-to-track seek: 0 # microseconds
drivedata: 0
# size offset fstype [fsize bsize cpg/sgs]
a: 19540789 65 4.2BSD 0 0 0 # (Cyl. 0 - 18569)
d: 19540864 0 unused 0 0 # (Cyl. 0 - 19082*)
On sparc64:
# disklabel -r -e -I raid0
[...snip...]
total sectors: 19539968
[...snip...]
2 partitions:
# size offset fstype [fsize bsize cpg/sgs]
a: 19540793 65 4.2BSD 0 0 0 # (Cyl. 0 - 18799)
c: 19539968 0 unused 0 0 # (Cyl. 0 - 19081)
Partitions should be created with offset 65, because sectors < than 65 sector
are marked as readonly and therefore can't be rewritten.
18.8.3. Ãreating PV, VG on raid disk
Physical volumes can be created on any disk like device and on any partition on
it we can use a or d on sparc64 c partitions. PV will label selected partition
as LVM used and add needed information to it.
PV is created on char disk device entry. As any other disk operation in the
NetBSD.
# lvm pvcreate /dev/rraid0a
For our example purpose I will create vg00 Volume Group. The first parameter of
vgcreate command is Volume Group name and second is PV created on raid. If you
later found that VG size is no sufficient and you need more space we will can
add it with vgextend command.
# lvm vgcreate vg00 /dev/rraid0a
# lvm vgextend vg00 /dev/rraid1a
Warning
If you add non-raid PV to your Volume Group your data are not safe anymore.
Therefore you should add raid based PV to VG if you want to keep your data
safe.
18.8.4. Ãreating LV's from VG located on raid disk
For our example purpose we will create Logical Volume named lv0. If you later
found that LV size is not sufficient for you can add it with lvresize command.
Note
You must also resize the filesystem, when you resize LV, otherwise you will not
see any filesystem change when you mount LV.
Warning
Be aware that to shrink LV you must first shrink the filesystem (and shrinking
of FFSv2 filesystems is not supported yet as of NetBSD 9.0).
This means that for FFSv2 filesystems, the -L-* option is not available in
NetBSD.
# lvm lvcreate -n lv0 -L 2G vg00
# lvm lvresize -L+2G vg00/lv0
All lv device nodes are created in the /dev/vg00/ directory. File system can be
create on LV with this command. After filesystem creation LV can be mounted to
system.
# newfs -O2 /dev/vg00/rlv0
# mount /dev/vg00/lv0 /mnt/
18.8.5. Éntegration of LV's in to the system
For Proper LVM integration you have to enable lvm rc.d script, which detect LVs
during boot and enables them. You have to add entry for Logical Volume to the /
etc/fstab file.
# cat /etc/rc.conf
[snip]
lvm=yes
# cat /etc/fstab
/dev/wd0a / ffs rw 1 1
/dev/vg00/lv0 /lv0/ ffs rw 1 1
[snip]
Chapter9. Ðluggable Authentication Modules (PAM)
Table of Contents
19.1. About
19.2. Introduction
19.3. Terms and conventions
19.3.1. Definitions
19.3.2. Usage examples
19.4. PAM Essentials
19.4.1. Facilities and primitives
19.4.2. Modules
19.4.3. Chains and policies
19.4.4. Transactions
19.5. PAM Configuration
19.5.1. PAM policy files
19.5.2. Breakdown of a configuration line
19.5.3. Policies
19.6. PAM modules
19.6.1. Common Modules
19.6.2. NetBSD-specific PAM Modules
19.7. PAM Application Programming
19.8. PAM Module Programming
19.9. Sample PAM Application
19.10. Sample PAM Module
19.11. Sample PAM Conversation Function
19.12. Further Reading
19.1. Ábout
This article describes the underlying principles and mechanisms of the
Pluggable Authentication Modules (PAM) library, and explains how to configure
PAM, how to integrate PAM into applications, and how to write PAM modules.
See Section Ä.3.2, "Networks Associates Technology's license on the PAM
article" for the license of this chapter.
19.2. Éntroduction
The Pluggable Authentication Modules (PAM) library is a generalized API for
authentication-related services which allows a system administrator to add new
authentication methods simply by installing new PAM modules, and to modify
authentication policies by editing configuration files.
PAM was defined and developed in 1995 by Vipin Samar and Charlie Lai of Sun
Microsystems, and has not changed much since. In 1997, the Open Group published
the X/Open Single Sign-on (XSSO) preliminary specification, which standardized
the PAM API and added extensions for single (or rather integrated) sign-on. At
the time of this writing, this specification has not yet been adopted as a
standard.
Although this article focuses primarily on FreeBSD 5.x and NetBSD 3.x, which
both use OpenPAM, it should be equally applicable to FreeBSD 4.x, which uses
Linux-PAM, and other operating systems such as Linux and Solaris?.
19.3. Ôerms and conventions
19.3.1. Äefinitions
The terminology surrounding PAM is rather confused. Neither Samar and Lai's
original paper nor the XSSO specification made any attempt at formally defining
terms for the various actors and entities involved in PAM, and the terms that
they do use (but do not define) are sometimes misleading and ambiguous. The
first attempt at establishing a consistent and unambiguous terminology was a
whitepaper written by Andrew G. Morgan (author of Linux-PAM) in 1999. While
Morgan's choice of terminology was a huge leap forward, it is in this author's
opinion by no means perfect. What follows is an attempt, heavily inspired by
Morgan, to define precise and unambiguous terms for all actors and entities
involved in PAM.
account
The set of credentials the applicant is requesting from the arbitrator.
applicant
The user or entity requesting authentication.
arbitrator
The user or entity who has the privileges necessary to verify the
applicant's credentials and the authority to grant or deny the request.
chain
A sequence of modules that will be invoked in response to a PAM request.
The chain includes information about the order in which to invoke the
modules, what arguments to pass to them, and how to interpret the results.
client
The application responsible for initiating an authentication request on
behalf of the applicant and for obtaining the necessary authentication
information from him.
facility
One of the four basic groups of functionality provided by PAM:
authentication, account management, session management and authentication
token update.
module
A collection of one or more related functions implementing a particular
authentication facility, gathered into a single (normally dynamically
loadable) binary file and identified by a single name.
policy
The complete set of configuration statements describing how to handle PAM
requests for a particular service. A policy normally consists of four
chains, one for each facility, though some services do not use all four
facilities.
server
The application acting on behalf of the arbitrator to converse with the
client, retrieve authentication information, verify the applicant's
credentials and grant or deny requests.
service
A class of servers providing similar or related functionality and requiring
similar authentication. PAM policies are defined on a per-service basis, so
all servers that claim the same service name will be subject to the same
policy.
session
The context within which service is rendered to the applicant by the
server. One of PAM's four facilities, session management, is concerned
exclusively with setting up and tearing down this context.
token
A chunk of information associated with the account, such as a password or
passphrase, which the applicant must provide to prove his identity.
transaction
A sequence of requests from the same applicant to the same instance of the
same server, beginning with authentication and session set-up and ending
with session tear-down.
19.3.2. Õsage examples
This section aims to illustrate the meanings of some of the terms defined above
by way of a handful of simple examples.
19.3.2.1. Ãlient and server are one
This simple example shows alice su(1)'ing to root.
$ whoami
alice
$ ls -l `which su`
-r-sr-xr-x 1 root wheel 10744 Dec 6 19:06 /usr/bin/su
$ su -
Password: xi3kiune
# whoami
root
* The applicant is alice.
* The account is root.
* The su(1) process is both client and server.
* The authentication token is xi3kiune.
* The arbitrator is root, which is why su(1) is setuid root.
19.3.2.2. Ãlient and server are separate
The example below shows eve try to initiate an ssh(1) connection to
login.example.com, ask to log in as bob, and succeed. Bob should have chosen a
better password!
$ whoami
eve
$ ssh bob@login.example.com
bob@login.example.com's password: god
Last login: Thu Oct 11 09:52:57 2001 from 192.168.0.1
NetBSD 3.0 (LOGIN) #1: Thu Mar 10 18:22:36 WET 2005
Welcome to NetBSD!
$
* The applicant is eve.
* The client is Eve's ssh(1) process.
* The server is the sshd(8) process on login.example.com
* The account is bob.
* The authentication token is god.
* Although this is not shown in this example, the arbitrator is root.
19.3.2.3. Óample policy
The following is FreeBSD's default policy for sshd:
sshd auth required pam_nologin.so no_warn
sshd auth required pam_unix.so no_warn try_first_pass
sshd account required pam_login_access.so
sshd account required pam_unix.so
sshd session required pam_lastlog.so no_fail
sshd password required pam_permit.so
* This policy applies to the sshd service (which is not necessarily
restricted to the sshd(8) server.)
* auth, account, session and password are facilities.
* pam_nologin.so, pam_unix.so, pam_login_access.so, pam_lastlog.so and
pam_permit.so are modules. It is clear from this example that pam_unix.so
provides at least two facilities (authentication and account management.)
There are some differences between FreeBSD and NetBSD PAM policies:
* By default, every configuration is done under /etc/pam.d.
* If configuration is non-existent, you will not have access to the system,
in contrast with FreeBSD that has a default policy of allowing
authentication.
* For authentication, NetBSD forces at least one required, requisite or
binding module to be present.
19.4. ÐAM Essentials
19.4.1. Æacilities and primitives
The PAM API offers six different authentication primitives grouped in four
facilities, which are described below.
auth
Authentication. This facility concerns itself with authenticating the
applicant and establishing the account credentials. It provides two
primitives:
+ pam_authenticate(3) authenticates the applicant, usually by requesting
an authentication token and comparing it with a value stored in a
database or obtained from an authentication server.
+ pam_setcred(3) establishes account credentials such as user ID, group
membership and resource limits.
account
Account management. This facility handles non-authentication-related issues
of account availability, such as access restrictions based on the time of
day or the server's work load. It provides a single primitive:
+ pam_acct_mgmt(3) verifies that the requested account is available.
session
Session management. This facility handles tasks associated with session
set-up and tear-down, such as login accounting. It provides two primitives:
+ pam_open_session(3) performs tasks associated with session set-up: add
an entry in the utmp and wtmp databases, start an SSH agent, etc.
+ pam_close_session(3) performs tasks associated with session tear-down:
add an entry in the utmp and wtmp databases, stop the SSH agent, etc.
password
Password management. This facility is used to change the authentication
token associated with an account, either because it has expired or because
the user wishes to change it. It provides a single primitive:
+ pam_chauthtok(3) changes the authentication token, optionally verifying
that it is sufficiently hard to guess, has not been used previously,
etc.
19.4.2. Íodules
Modules are a very central concept in PAM; after all, they are the "M" in "PAM"
. A PAM module is a self-contained piece of program code that implements the
primitives in one or more facilities for one particular mechanism; possible
mechanisms for the authentication facility, for instance, include the UNIXpassword database, NIS, LDAP and Radius.
19.4.2.1. Íodule Naming
FreeBSD and NetBSD implement each mechanism in a single module, named pam_
mechanism.so (for instance, pam_unix.so for the UNIXmechanism.) Other
implementations sometimes have separate modules for separate facilities, and
include the facility name as well as the mechanism name in the module name. To
name one example, Solaris? has a pam_dial_auth.so.1 module which is commonly
used to authenticate dialup users. Also, almost every module has a man page
with the same name, i.e.: pam_unix(8) explains how the pam_unix.so module
works.
19.4.2.2. Íodule Versioning
FreeBSD's original PAM implementation, based on Linux-PAM, did not use version
numbers for PAM modules. This would commonly cause problems with legacy
applications, which might be linked against older versions of the system
libraries, as there was no way to load a matching version of the required
modules.
OpenPAM, on the other hand, looks for modules that have the same version number
as the PAM library (currently 2 in FreeBSD and 0 in NetBSD), and only falls
back to an unversioned module if no versioned module could be loaded. Thus
legacy modules can be provided for legacy applications, while allowing new (or
newly built) applications to take advantage of the most recent modules.
Although Solaris? PAM modules commonly have a version number, they're not truly
versioned, because the number is a part of the module name and must be included
in the configuration.
19.4.2.3. Íodule Path
There isn't a common directory for storing PAM modules. Under FreeBSD, they are
located at /usr/lib and, under NetBSD, you can find them in /usr/lib/security.
19.4.3. Ãhains and policies
When a server initiates a PAM transaction, the PAM library tries to load a
policy for the service specified in the pam_start(3) call. The policy specifies
how authentication requests should be processed, and is defined in a
configuration file. This is the other central concept in PAM: the possibility
for the admin to tune the system security policy (in the wider sense of the
word) simply by editing a text file.
A policy consists of four chains, one for each of the four PAM facilities. Each
chain is a sequence of configuration statements, each specifying a module to
invoke, some (optional) parameters to pass to the module, and a control flag
that describes how to interpret the return code from the module.
Understanding the control flags is essential to understanding PAM configuration
files. There are a number of different control flags:
binding
If the module succeeds and no earlier module in the chain has failed, the
chain is immediately terminated and the request is granted. If the module
fails, the rest of the chain is executed, but the request is ultimately
denied.
This control flag was introduced by Sun in Solaris? 9 (SunOS? 5.9), and is
also supported by OpenPAM.
required
If the module succeeds, the rest of the chain is executed, and the request
is granted unless some other module fails. If the module fails, the rest of
the chain is also executed, but the request is ultimately denied.
requisite
If the module succeeds, the rest of the chain is executed, and the request
is granted unless some other module fails. If the module fails, the chain
is immediately terminated and the request is denied.
sufficient
If the module succeeds and no earlier module in the chain has failed, the
chain is immediately terminated and the request is granted. If the module
fails, the module is ignored and the rest of the chain is executed.
As the semantics of this flag may be somewhat confusing, especially when it
is used for the last module in a chain, it is recommended that the binding
control flag be used instead if the implementation supports it.
optional
The module is executed, but its result is ignored. If all modules in a
chain are marked optional, all requests will always be granted.
When a server invokes one of the six PAM primitives, PAM retrieves the chain
for the facility the primitive belongs to, and invokes each of the modules
listed in the chain, in the order they are listed, until it reaches the end, or
determines that no further processing is necessary (either because a binding or
sufficient module succeeded, or because a requisite module failed.) The request
is granted if and only if at least one module was invoked, and all non-optional
modules succeeded.
Note that it is possible, though not very common, to have the same module
listed several times in the same chain. For instance, a module that looks up
user names and passwords in a directory server could be invoked multiple times
with different parameters specifying different directory servers to contact.
PAM treat different occurrences of the same module in the same chain as
different, unrelated modules.
19.4.4. Ôransactions
The lifecycle of a typical PAM transaction is described below. Note that if any
of these steps fails, the server should report a suitable error message to the
client and abort the transaction.
1. If necessary, the server obtains arbitrator credentials through a mechanism
independent of PAM--most commonly by virtue of having been started by root,
or of being setuid root.
2. The server calls pam_start(3) to initialize the PAM library and specify its
service name and the target account, and register a suitable conversation
function.
3. The server obtains various information relating to the transaction (such as
the applicant's user name and the name of the host the client runs on) and
submits it to PAM using pam_set_item(3).
4. The server calls pam_authenticate(3) to authenticate the applicant.
5. The server calls pam_acct_mgmt(3) to verify that the requested account is
available and valid. If the password is correct but has expired,
pam_acct_mgmt(3) will return PAM_NEW_AUTHTOK_REQD instead of PAM_SUCCESS.
6. If the previous step returned PAM_NEW_AUTHTOK_REQD, the server now calls
pam_chauthtok(3) to force the client to change the authentication token for
the requested account.
7. Now that the applicant has been properly authenticated, the server calls
pam_setcred(3) to establish the credentials of the requested account. It is
able to do this because it acts on behalf of the arbitrator, and holds the
arbitrator's credentials.
8. Once the correct credentials have been established, the server calls
pam_open_session(3) to set up the session.
9. The server now performs whatever service the client requested--for
instance, provide the applicant with a shell.
10. Once the server is done serving the client, it calls pam_close_session(3)
to tear down the session.
11. Finally, the server calls pam_end(3) to notify the PAM library that it is
done and that it can release whatever resources it has allocated in the
course of the transaction.
19.5. ÐAM Configuration
19.5.1. ÐAM policy files
19.5.1.1. Ôhe /etc/pam.conf file
The traditional PAM policy file is /etc/pam.conf. This file contains all the
PAM policies for your system. Each line of the file describes one step in a
chain, as shown below:
login auth required pam_nologin.so no_warn
The fields are, in order: service name, facility name, control flag, module
name, and module arguments. Any additional fields are interpreted as additional
module arguments.
A separate chain is constructed for each service / facility pair, so while the
order in which lines for the same service and facility appear is significant,
the order in which the individual services and facilities are listed is not.
The examples in the original PAM paper grouped configuration lines by facility,
and the Solaris? stock pam.conf still does that, but FreeBSD's stock
configuration groups configuration lines by service. Either way is fine; either
way makes equal sense.
19.5.1.2. Ôhe /etc/pam.d directory
OpenPAM and Linux-PAM support an alternate configuration mechanism, which is
the preferred mechanism in FreeBSD and NetBSD. In this scheme, each policy is
contained in a separate file bearing the name of the service it applies to.
These files are stored in /etc/pam.d/.
These per-service policy files have only four fields instead of pam.conf's
five: the service name field is omitted. Thus, instead of the sample pam.conf
line from the previous section, one would have the following line in /etc/pam.d
/login:
auth required pam_nologin.so no_warn
As a consequence of this simplified syntax, it is possible to use the same
policy for multiple services by linking each service name to a same policy
file. For instance, to use the same policy for the su and sudo services, one
could do as follows:
# cd /etc/pam.d
# ln -s su sudo
This works because the service name is determined from the file name rather
than specified in the policy file, so the same file can be used for multiple
differently-named services.
Since each service's policy is stored in a separate file, the pam.d mechanism
also makes it very easy to install additional policies for third-party software
packages.
19.5.1.3. Ôhe policy search order
As we have seen above, PAM policies can be found in a number of places. If no
configuration file is found for a particular service, the /etc/pam.d/other is
used instead. If that file does not exist, /etc/pam.conf is searched for
entries matching he specified service or, failing that, the "other" service.
It is essential to understand that PAM's configuration system is centered on
chains.
19.5.2. Âreakdown of a configuration line
As explained in the PAM policy files section, each line in /etc/pam.conf
consists of four or more fields: the service name, the facility name, the
control flag, the module name, and zero or more module arguments.
The service name is generally (though not always) the name of the application
the statement applies to. If you are unsure, refer to the individual
application's documentation to determine what service name it uses.
Note that if you use /etc/pam.d/ instead of /etc/pam.conf, the service name is
specified by the name of the policy file, and omitted from the actual
configuration lines, which then start with the facility name.
The facility is one of the four facility keywords described in the Facilities
and primitives section.
Likewise, the control flag is one of the four keywords described in the Chains
and policies section, describing how to interpret the return code from the
module. Linux-PAM supports an alternate syntax that lets you specify the action
to associate with each possible return code, but this should be avoided as it
is non-standard and closely tied in with the way Linux-PAM dispatches service
calls (which differs greatly from the way Solaris? and OpenPAM do it.)
Unsurprisingly, OpenPAM does not support this syntax.
19.5.3. Ðolicies
To configure PAM correctly, it is essential to understand how policies are
interpreted.
When an application calls pam_start(3), the PAM library loads the policy for
the specified service and constructs four module chains (one for each
facility.) If one or more of these chains are empty, the corresponding chains
from the policy for the other service are substituted.
When the application later calls one of the six PAM primitives, the PAM library
retrieves the chain for the corresponding facility and calls the appropriate
service function in each module listed in the chain, in the order in which they
were listed in the configuration. After each call to a service function, the
module type and the error code returned by the service function are used to
determine what happens next. With a few exceptions, which we discuss below, the
following table applies:
Table9.1. ÐAM chain execution summary
+-----------------------------------------------------------+
| | PAM_SUCCESS |PAM_IGNORE| other |
|----------+-----------------+----------+-------------------|
|binding |if (!fail) break;|- |fail = true; |
|----------+-----------------+----------+-------------------|
|required |- |- |fail = true; |
|----------+-----------------+----------+-------------------|
|requisite |- |- |fail = true; break;|
|----------+-----------------+----------+-------------------|
|sufficient|if (!fail) break;|- |- |
|----------+-----------------+----------+-------------------|
|optional |- |- |- |
+-----------------------------------------------------------+
If fail is true at the end of a chain, or when a "break" is reached, the
dispatcher returns the error code returned by the first module that failed.
Otherwise, it returns PAM_SUCCESS.
The first exception of note is that the error code PAM_NEW_AUTHTOK_REQD is
treated like a success, except that if no module failed, and at least one
module returned PAM_NEW_AUTHTOK_REQD, the dispatcher will return
PAM_NEW_AUTHTOK_REQD.
The second exception is that pam_setcred(3) treats binding and sufficient
modules as if they were required.
The third and final exception is that pam_chauthtok(3) runs the entire chain
twice (once for preliminary checks and once to actually set the password), and
in the preliminary phase it treats binding and sufficient modules as if they
were required.
19.6. ÐAM modules
19.6.1. Ãommon Modules
19.6.1.1. ðam_deny(8)
The pam_deny(8) module is one of the simplest modules available; it responds to
any request with PAM_AUTH_ERR. It is useful for quickly disabling a service
(add it to the top of every chain), or for terminating chains of sufficient
modules.
19.6.1.2. ðam_echo(8)
The pam_echo(8) module simply passes its arguments to the conversation function
as a PAM_TEXT_INFO message. It is mostly useful for debugging, but can also
serve to display messages such as "Unauthorized access will be prosecuted"
before starting the authentication procedure.
19.6.1.3. ðam_exec(8)
The pam_exec(8) module takes its first argument to be the name of a program to
execute, and the remaining arguments are passed to that program as command-line
arguments. One possible application is to use it to run a program at login time
which mounts the user's home directory.
19.6.1.4. ðam_ftpusers(8)
The pam_ftpusers(8) module successes if and only if the user is listed in /etc/
ftpusers. Currently, in NetBSD, this module doesn't understand the extended
syntax of ftpd(8), but this will be fixed in the future.
19.6.1.5. ðam_group(8)
The pam_group(8) module accepts or rejects applicants on the basis of their
membership in a particular file group (normally wheel for su(1)). It is
primarily intended for maintaining the traditional behaviour of BSD su(1), but
has many other uses, such as excluding certain groups of users from a
particular service.
In NetBSD, there is an argument called authenticate in which the user is asked
to authenticate using his own password.
19.6.1.6. ðam_guest(8)
The pam_guest(8) module allows guest logins using fixed login names. Various
requirements can be placed on the password, but the default behaviour is to
allow any password as long as the login name is that of a guest account. The
pam_guest(8) module can easily be used to implement anonymous FTP logins.
19.6.1.7. ðam_krb5(8)
The pam_krb5(8) module provides functions to verify the identity of a user and
to set user specific credentials using Kerberos 5. It prompts the user for a
password and obtains a new Kerberos TGT for the principal. The TGT is verified
by obtaining a service ticket for the local host. The newly acquired
credentials are stored in a credential cache and the environment variable
KRB5CCNAME is set appropriately. The credentials cache should be destroyed by
the user at logout with kdestroy(1).
19.6.1.8. ðam_ksu(8)
The pam_ksu(8) module provides only authentication services for Kerberos 5 to
determine whether or not the applicant is authorized to obtain the privileges
of the target account.
19.6.1.9. ðam_lastlog(8)
The pam_lastlog(8) module provides only session management services. It records
the session in utmp(5), utmpx(5), wtmp(5), wtmpx(5), lastlog(5) and lastlogx(5)
databases.
19.6.1.10. ðam_login_access(8)
The pam_login_access(8) module provides an implementation of the account
management primitive which enforces the login restrictions specified in the
login.access(5) table.
19.6.1.11. ðam_nologin(8)
The pam_nologin(8) module refuses non-root logins when /var/run/nologin exists.
This file is normally created by shutdown(8) when less than five minutes remain
until the scheduled shutdown time.
19.6.1.12. ðam_permit(8)
The pam_permit(8) module is one of the simplest modules available; it responds
to any request with PAM_SUCCESS. It is useful as a placeholder for services
where one or more chains would otherwise be empty.
19.6.1.13. ðam_radius(8)
The pam_radius(8) module provides authentication services based upon the RADIUS
(Remote Authentication Dial In User Service) protocol.
19.6.1.14. ðam_rhosts(8)
The pam_rhosts(8) module provides only authentication services. It reports
success if and only if the target user's ID is not 0 and the remote host and
user are listed in /etc/hosts.equiv or in the target user's ~/.rhosts.
19.6.1.15. ðam_rootok(8)
The pam_rootok(8) module reports success if and only if the real user id of the
process calling it (which is assumed to be run by the applicant) is 0. This is
useful for non-networked services such as su(1) or passwd(1), to which the root
should have automatic access.
19.6.1.16. ðam_securetty(8)
The pam_securetty(8) module provides only account services. It is used when the
applicant is attempting to authenticate as superuser, and the process is
attached to an insecure TTY.
19.6.1.17. ðam_self(8)
The pam_self(8) module reports success if and only if the names of the
applicant matches that of the target account. It is most useful for
non-networked services such as su(1), where the identity of the applicant can
be easily verified.
19.6.1.18. ðam_ssh(8)
The pam_ssh(8) module provides both authentication and session services. The
authentication service allows users who have passphrase-protected SSH secret
keys in their ~/.ssh directory to authenticate themselves by typing their
passphrase. The session service starts ssh-agent(1) and preloads it with the
keys that were decrypted in the authentication phase. This feature is
particularly useful for local logins, whether in X (using xdm(1) or another
PAM-aware X login manager) or at the console.
This module implements what is fundamentally a password authentication scheme.
Care should be taken to only use this module over a secure session (secure TTY,
encrypted session, etc.), otherwise the user's SSH passphrase could be
compromised.
Additional consideration should be given to the use of pam_ssh(8). Users often
assume that file permissions are sufficient to protect their SSH keys, and thus
use weak or no passphrases. Since the system administrator has no effective
means of enforcing SSH passphrase quality, this has the potential to expose the
system to security risks.
19.6.1.19. ðam_unix(8)
The pam_unix(8) module implements traditional UNIXpassword authentication,
using getpwnam(3) under FreeBSD or getpwnam_r(3) under NetBSD to obtain the
target account's password and compare it with the one provided by the
applicant. It also provides account management services (enforcing account and
password expiration times) and password-changing services. This is probably the
single most useful module, as the great majority of admins will want to
maintain historical behaviour for at least some services.
19.6.2. ÎetBSD-specific PAM Modules
19.6.2.1. ðam_skey(8)
The pam_skey(8) module implements S/Key One Time Password (OTP) authentication
methods, using the /etc/skeykeys database.
19.7. ÐAM Application Programming
This section has not yet been written.
19.8. ÐAM Module Programming
This section has not yet been written.
19.9. Óample PAM Application
The following is a minimal implementation of su(1) using PAM. Note that it uses
the OpenPAM-specific openpam_ttyconv(3) conversation function, which is
prototyped in security/openpam.h. If you wish build this application on a
system with a different PAM library, you will have to provide your own
conversation function. A robust conversation function is surprisingly difficult
to implement; the one presented in the Sample PAM Conversation Function
sub-chapter is a good starting point, but should not be used in real-world
applications.
#include <sys/param.h>
#include <sys/wait.h>
#include <err.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <security/pam_appl.h>
#include <security/openpam.h> /* for openpam_ttyconv() */
extern char **environ;
static pam_handle_t *pamh;
static struct pam_conv pamc;
static void
usage(void)
{
fprintf(stderr, "Usage: su [login [args]]\n");
exit(1);
}
int
main(int argc, char *argv[])
{
char hostname[MAXHOSTNAMELEN];
const char *user, *tty;
char **args, **pam_envlist, **pam_env;
struct passwd *pwd;
int o, pam_err, status;
pid_t pid;
while ((o = getopt(argc, argv, "h")) != -1)
switch (o) {
case 'h':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc > 0) {
user = *argv;
--argc;
++argv;
} else {
user = "root";
}
/* initialize PAM */
pamc.conv = &openpam_ttyconv;
pam_start("su", user, &pamc, &pamh);
/* set some items */
gethostname(hostname, sizeof(hostname));
if ((pam_err = pam_set_item(pamh, PAM_RHOST, hostname)) != PAM_SUCCESS)
goto pamerr;
user = getlogin();
if ((pam_err = pam_set_item(pamh, PAM_RUSER, user)) != PAM_SUCCESS)
goto pamerr;
tty = ttyname(STDERR_FILENO);
if ((pam_err = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS)
goto pamerr;
/* authenticate the applicant */
if ((pam_err = pam_authenticate(pamh, 0)) != PAM_SUCCESS)
goto pamerr;
if ((pam_err = pam_acct_mgmt(pamh, 0)) == PAM_NEW_AUTHTOK_REQD)
pam_err = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
if (pam_err != PAM_SUCCESS)
goto pamerr;
/* establish the requested credentials */
if ((pam_err = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS)
goto pamerr;
/* authentication succeeded; open a session */
if ((pam_err = pam_open_session(pamh, 0)) != PAM_SUCCESS)
goto pamerr;
/* get mapped user name; PAM may have changed it */
pam_err = pam_get_item(pamh, PAM_USER, (const void **)&user);
if (pam_err != PAM_SUCCESS || (pwd = getpwnam(user)) == NULL)
goto pamerr;
/* export PAM environment */
if ((pam_envlist = pam_getenvlist(pamh)) != NULL) {
for (pam_env = pam_envlist; *pam_env != NULL; ++pam_env) {
putenv(*pam_env);
free(*pam_env);
}
free(pam_envlist);
}
/* build argument list */
if ((args = calloc(argc + 2, sizeof *args)) == NULL) {
warn("calloc()");
goto err;
}
*args = pwd->pw_shell;
memcpy(args + 1, argv, argc * sizeof *args);
/* fork and exec */
switch ((pid = fork())) {
case -1:
warn("fork()");
goto err;
case 0:
/* child: give up privs and start a shell */
/* set uid and groups */
if (initgroups(pwd->pw_name, pwd->pw_gid) == -1) {
warn("initgroups()");
_exit(1);
}
if (setgid(pwd->pw_gid) == -1) {
warn("setgid()");
_exit(1);
}
if (setuid(pwd->pw_uid) == -1) {
warn("setuid()");
_exit(1);
}
execve(*args, args, environ);
warn("execve()");
_exit(1);
default:
/* parent: wait for child to exit */
waitpid(pid, &status, 0);
/* close the session and release PAM resources */
pam_err = pam_close_session(pamh, 0);
pam_end(pamh, pam_err);
exit(WEXITSTATUS(status));
}
pamerr:
fprintf(stderr, "Sorry\n");
err:
pam_end(pamh, pam_err);
exit(1);
}
19.10. Óample PAM Module
The following is a minimal implementation of pam_unix(8), offering only
authentication services. It should build and run with most PAM implementations,
but takes advantage of OpenPAM extensions if available: note the use of
pam_get_authtok(3), which enormously simplifies prompting the user for a
password.
#include <sys/param.h>
#include <pwd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <security/pam_modules.h>
#include <security/pam_appl.h>
#ifndef _OPENPAM
static char password_prompt[] = "Password:";
#endif
#ifndef PAM_EXTERN
#define PAM_EXTERN
#endif
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
#ifndef _OPENPAM
const void *ptr;
const struct pam_conv *conv;
struct pam_message msg;
const struct pam_message *msgp;
struct pam_response *resp;
#endif
struct passwd *pwd;
const char *user;
char *crypt_password, *password;
int pam_err, retry;
/* identify user */
if ((pam_err = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS)
return (pam_err);
if ((pwd = getpwnam(user)) == NULL)
return (PAM_USER_UNKNOWN);
/* get password */
#ifndef _OPENPAM
pam_err = pam_get_item(pamh, PAM_CONV, &ptr);
if (pam_err != PAM_SUCCESS)
return (PAM_SYSTEM_ERR);
conv = ptr;
msg.msg_style = PAM_PROMPT_ECHO_OFF;
msg.msg = password_prompt;
msgp = &msg;
#endif
password = NULL;
for (retry = 0; retry < 3; ++retry) {
#ifdef _OPENPAM
pam_err = pam_get_authtok(pamh, PAM_AUTHTOK,
(const char **)&password, NULL);
#else
resp = NULL;
pam_err = (*conv->conv)(1, &msgp, &resp, conv->appdata_ptr);
if (resp != NULL) {
if (pam_err == PAM_SUCCESS)
password = resp->resp;
else
free(resp->resp);
free(resp);
}
#endif
if (pam_err == PAM_SUCCESS)
break;
}
if (pam_err == PAM_CONV_ERR)
return (pam_err);
if (pam_err != PAM_SUCCESS)
return (PAM_AUTH_ERR);
/* compare passwords */
if ((!pwd->pw_passwd[0] && (flags & PAM_DISALLOW_NULL_AUTHTOK)) ||
(crypt_password = crypt(password, pwd->pw_passwd)) == NULL ||
strcmp(crypt_password, pwd->pw_passwd) != 0)
pam_err = PAM_AUTH_ERR;
else
pam_err = PAM_SUCCESS;
#ifndef _OPENPAM
free(password);
#endif
return (pam_err);
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (PAM_SUCCESS);
}
PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (PAM_SUCCESS);
}
PAM_EXTERN int
pam_sm_open_session(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (PAM_SUCCESS);
}
PAM_EXTERN int
pam_sm_close_session(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (PAM_SUCCESS);
}
PAM_EXTERN int
pam_sm_chauthtok(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
return (PAM_SERVICE_ERR);
}
#ifdef PAM_MODULE_ENTRY
PAM_MODULE_ENTRY("pam_unix");
#endif
19.11. Óample PAM Conversation Function
The conversation function presented below is a greatly simplified version of
OpenPAM's openpam_ttyconv(3). It is fully functional, and should give the
reader a good idea of how a conversation function should behave, but it is far
too simple for real-world use. Even if you're not using OpenPAM, feel free to
download the source code and adapt openpam_ttyconv(3) to your uses; we believe
it to be as robust as a tty-oriented conversation function can reasonably get.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <security/pam_appl.h>
int
converse(int n, const struct pam_message **msg,
struct pam_response **resp, void *data)
{
struct pam_response *aresp;
char buf[PAM_MAX_RESP_SIZE];
int i;
data = data;
if (n <= 0 || n > PAM_MAX_NUM_MSG)
return (PAM_CONV_ERR);
if ((aresp = calloc(n, sizeof *aresp)) == NULL)
return (PAM_BUF_ERR);
for (i = 0; i < n; ++i) {
aresp[i].resp_retcode = 0;
aresp[i].resp = NULL;
switch (msg[i]->msg_style) {
case PAM_PROMPT_ECHO_OFF:
aresp[i].resp = strdup(getpass(msg[i]->msg));
if (aresp[i].resp == NULL)
goto fail;
break;
case PAM_PROMPT_ECHO_ON:
fputs(msg[i]->msg, stderr);
if (fgets(buf, sizeof buf, stdin) == NULL)
goto fail;
aresp[i].resp = strdup(buf);
if (aresp[i].resp == NULL)
goto fail;
break;
case PAM_ERROR_MSG:
fputs(msg[i]->msg, stderr);
if (strlen(msg[i]->msg) > 0 &&
msg[i]->msg[strlen(msg[i]->msg) - 1] != '\n')
fputc('\n', stderr);
break;
case PAM_TEXT_INFO:
fputs(msg[i]->msg, stdout);
if (strlen(msg[i]->msg) > 0 &&
msg[i]->msg[strlen(msg[i]->msg) - 1] != '\n')
fputc('\n', stdout);
break;
default:
goto fail;
}
}
*resp = aresp;
return (PAM_SUCCESS);
fail:
for (i = 0; i < n; ++i) {
if (aresp[i].resp != NULL) {
memset(aresp[i].resp, 0, strlen(aresp[i].resp));
free(aresp[i].resp);
}
}
memset(aresp, 0, n * sizeof *aresp);
*resp = NULL;
return (PAM_CONV_ERR);
}
19.12. Æurther Reading
Bibliography
Papers
[sun-pam] Making Login Services Independent of Authentication Technologies.
Vipin Samar and Charlie Lai. Sun Microsystems.
[opengroup-singlesignon] X/Open Single Sign-on Preliminary Specification. The
Open Group. 1-85912-144-6. June 1997.
[kernelorg-pamdraft] Pluggable Authentication Modules. Andrew G. Morgan.
October 6, 1999.
User Manuals
[sun-pamadmin] PAM Administration. Sun Microsystems.
Related Web pages
[openpam-website] OpenPAM homepage. Dag-Erling Smøògrav. ThinkSec AS.
[linuxpam-website] Linux-PAM homepage. Andrew G. Morgan.
[solarispam-website] Solaris PAM homepage. Sun Microsystems.
Chapter0. Ôuning NetBSD
Table of Contents
20.1. Introduction
20.1.1. Overview
20.2. Tuning Considerations
20.2.1. General System Configuration
20.2.2. System Services
20.2.3. The NetBSD Kernel
20.3. Visual Monitoring Tools
20.3.1. The top Process Monitor
20.3.2. The sysstat utility
20.4. Monitoring Tools
20.4.1. fstat
20.4.2. iostat
20.4.3. ps
20.4.4. vmstat
20.5. Network Tools
20.5.1. ping
20.5.2. traceroute
20.5.3. netstat
20.5.4. tcpdump
20.6. Accounting
20.6.1. Accounting
20.6.2. Reading Accounting Information
20.6.3. How to Put Accounting to Use
20.7. Kernel Profiling
20.7.1. Getting Started
20.7.2. Interpretation of kgmon Output
20.7.3. Putting it to Use
20.7.4. Summary
20.8. System Tuning
20.8.1. Using sysctl
20.8.2. tmpfs & mfs
20.8.3. Journaling
20.8.4. LFS
20.9. Kernel Tuning
20.9.1. Preparing to Recompile a Kernel
20.9.2. Configuring the Kernel
20.9.3. Building the New Kernel
20.9.4. Shrinking the NetBSD kernel
20.1. Éntroduction
20.1.1. Ïverview
This section covers a variety of performance tuning topics. It attempts to span
tuning from the perspective of the system administrator to systems programmer.
The art of performance tuning itself is very old. To tune something means to
make it operate more efficiently, whether one is referring to a NetBSD based
technical server or a vacuum cleaner, the goal is to improve something, whether
that be the way something is done, how it works or how it is put together.
20.1.1.1. ×hat is Performance Tuning?
A view from 10,000 feet pretty much dictates that everything we do is task
oriented, this pertains to a NetBSD system as well. When the system boots, it
automatically begins to perform a variety of tasks. When a user logs in, they
usually have a wide variety of tasks they have to accomplish. In the scope of
these documents, however, performance tuning strictly means to improve how
efficient a NetBSD system performs.
The most common thought that crops into someone's mind when they think "tuning"
is some sort of speed increase or decreasing the size of the kernel - while
those are ways to improve performance, they are not the only ends an
administrator may have to take for increasing efficiency. For our purposes,
performance tuning means this: To make a NetBSD system operate in an optimum
state.
Which could mean a variety of things, not necessarily speed enhancements. A
good example of this is filesystem formatting parameters, on a system that has
a lot of small files (say like a source repository) an administrator may need
to increase the number of inodes by making their size smaller (say down to
1024k) and then increasing the amount of inodes. In this case the number of
inodes was increased, however, it keeps the administrator from getting those
nasty out of inodes messages, which ultimately makes the system more efficient.
Tuning normally revolves around finding and eliminating bottlenecks. Most of
the time, such bottlenecks are spurious, for example, a release of Mozilla that
does not quite handle java applets too well can cause Mozilla to start
crunching the CPU, especially applets that are not done well. Occasions when
processes seem to spin off into nowhere and eat CPU are almost always resolved
with a kill. There are instances, however, when resolving bottlenecks takes a
lot longer, for example, say an rsynced server is just getting larger and
larger. Slowly, performance begins to fade and the administrator may have to
take some sort of action to speed things up, however, the situation is relative
to say an emergency like an instantly spiked CPU.
20.1.1.2. ×hen does one tune?
Many NetBSD users rarely have to tune a system. The GENERIC kernel may run just
fine and the layout/configuration of the system may do the job as well. By the
same token, as a pragma it is always good to know how to tune a system. Most
often tuning comes as a result of a sudden bottleneck issue (which may occur
randomly) or a gradual loss of performance. It does happen in a sense to
everyone at some point, one process that is eating the CPU is a bottleneck as
much as a gradual increase in paging. So, the question should not be when to
tune so much as when to learn to tune.
One last time to tune is if you can tune in a preventive manner (and you think
you might need to) then do it. One example of this was on a system that needed
to be able to reboot quickly. Instead of waiting, I did everything I could to
trim the kernel and make sure there was absolutely nothing running that was not
needed, I even removed drivers that did have devices, but were never used (lp).
The result was reducing reboot time by nearly two-thirds. In the long run, it
was a smart move to tune it before it became an issue.
20.1.1.3. ×hat these Documents Will Not Cover
Before I wrap up the introduction, I think it is important to note what these
documents will not cover. This guide will pertain only to the core NetBSD
system. In other words, it will not cover tuning a web server's configuration
to make it run better; however, it might mention how to tune NetBSD to run
better as a web server. The logic behind this is simple: web servers, database
software, etc. are third party and almost limitless. I could easily get mired
down in details that do not apply to the NetBSD system. Almost all third party
software have their own documentation about tuning anyhow.
20.1.1.4. Èow Examples are Laid Out
Since there is ample man page documentation, only used options and arguments
with examples are discussed. In some cases, material is truncated for brevity
and not thoroughly discussed because, quite simply, there is too much. For
example, every single device driver entry in the kernel will not be discussed,
however, an example of determining whether or not a given system needs one will
be. Nothing in this Guide is concrete, tuning and performance are very
subjective, instead, it is a guide for the reader to learn what some of the
tools available to them can do.
20.2. Ôuning Considerations
Tuning a system is not really too difficult when pro-active tuning is the
approach. This document approaches tuning from a "before it comes up" approach.
While tuning in spare time is considerably easier versus say, a server that is
almost completely bogged down to 0.1% idle time, there are still a few things
that should be mulled over about tuning before actually doing it, hopefully,
before a system is even installed.
20.2.1. Çeneral System Configuration
Of course, how the system is setup makes a big difference. Sometimes small
items can be overlooked which may in fact cause some sort of long term
performance problem.
20.2.1.1. Æilesystems and Disks
How the filesystem is laid out relative to disk drives is very important. On
hardware RAID systems, it is not such a big deal, but, many NetBSD users
specifically use NetBSD on older hardware where hardware RAID simply is not an
option. The idea of / being close to the first drive is a good one, but for
example if there are several drives to choose from that will be the first one,
is the best performing the one that / will be on? On a related note, is it wise
to split off /usr? Will the system see heavy usage say in /usr/pkgsrc? It might
make sense to slap a fast drive in and mount it under /usr/pkgsrc, or it might
not. Like all things in performance tuning, this is subjective.
20.2.1.2. Ówap Configuration
There are three schools of thought on swap size and about fifty on using split
swap files with prioritizing and how that should be done. In the swap size
arena, the vendor schools (at least most commercial ones) usually have their
own formulas per OS. As an example, on a particular version of HP-UX with a
particular version of Oracle the formula was:
2.5 ÇB Îumber_of_processor
Well, that all really depends on what type of usage the database is having and
how large it is, for instance if it is so large that it must be distributed,
that formula does not fit well.
The next school of thought about swap sizing is sort of strange but makes some
sense, it says, if possible, get a reference amount of memory used by the
system. It goes something like this:
1. Startup a machine and estimate total memory needs by running everything
that may ever be needed at once. Databases, web servers .... whatever.
Total up the amount.
2. Add a few MB for padding.
3. Subtract the amount of physical RAM from this total.
If the amount leftover is 3 times the size of physical RAM, consider getting
more RAM. The problem, of course, is figuring out what is needed and how much
space it will take. There is also another flaw in this method, some programs do
not behave well. A glaring example of misbehaved software is web browsers. On
certain versions of Netscape, when something went wrong it had a tendency to
runaway and eat swap space. So, the more spare space available, the more time
to kill it.
Last and not least is the tried and true PHYSICAL_RAM * 2 method. On modern
machines and even older ones (with limited purpose of course) this seems to
work best.
All in all, it is hard to tell when swapping will start. Even on small 16MB RAM
machines (and less) NetBSD has always worked well for most people until
misbehaving software is running.
20.2.2. Óystem Services
On servers, system services have a large impact. Getting them to run at their
best almost always requires some sort of network level change or a fundamental
speed increase in the underlying system (which of course is what this is all
about). There are instances when some simple solutions can improve services.
One example, an ftp server is becoming slower and a new release of the ftp
server that is shipped with the system comes out that, just happens to run
faster. By upgrading the ftp software, a performance boost is accomplished.
Another good example where services are concerned is the age old question: "To
use inetd or not to use inetd?" A great service example is pop3. Pop3
connections can conceivably clog up inetd. While the pop3 service itself starts
to degrade slowly, other services that are multiplexed through inetd will also
degrade (in some case more than pop3). Setting up pop3 to run outside of inetd
and on its own may help.
20.2.3. Ôhe NetBSD Kernel
The NetBSD kernel obviously plays a key role in how well a system performs,
while rebuilding and tuning the kernel is covered later in the text, it is
worth discussing in the local context from a high level.
Tuning the NetBSD kernel really involves three main areas:
1. removing unrequired drivers
2. configuring options
3. system settings
20.2.3.1. Òemoving Unrequired Drivers
Taking drivers out of the kernel that are not needed achieves several results;
first, the system boots faster since the kernel is smaller, second again since
the kernel is smaller, more memory is free to users and processes and third,
the kernel tends to respond quicker.
20.2.3.2. Ãonfiguring Options
Configuring options such as enabling/disabling certain subsystems, specific
hardware and filesystems can also improve performance pretty much the same way
removing unrequired drivers does. A very simple example of this is a FTP server
that only hosts ftp files - nothing else. On this particular server there is no
need to have anything but native filesystem support and perhaps a few options
to help speed things along. Why would it ever need NTFS support for example?
Besides, if it did, support for NTFS could be added at some later time. In an
opposite case, a workstation may need to support a lot of different filesystem
types to share and access files.
20.2.3.3. Óystem Settings
System wide settings are controlled by the kernel, a few examples are
filesystem settings, network settings and core kernel settings such as the
maximum number of processes. Almost all system settings can be at least looked
at or modified via the sysctl facility. Examples using the sysctl facility are
given later on.
20.3. Öisual Monitoring Tools
NetBSD ships a variety of performance monitoring tools with the system. Most of
these tools are common on all UNIX systems. In this section some example usage
of the tools is given with interpretation of the output.
20.3.1. Ôhe top Process Monitor
The top monitor does exactly what it says: it displays the CPU hogs on the
system. To run the monitor, simply type top at the prompt. Without any
arguments, it should look like:
load averages: 0.09, 0.12, 0.08 20:23:41
21 processes: 20 sleeping, 1 on processor
CPU states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle
Memory: 15M Act, 1104K Inact, 208K Wired, 22M Free, 129M Swap free
PID USERNAME PRI NICE SIZE RES STATE TIME WCPU CPU COMMAND
13663 root 2 0 1552K 1836K sleep 0:08 0.00% 0.00% httpd
127 root 10 0 129M 4464K sleep 0:01 0.00% 0.00% mount_mfs
22591 root 2 0 388K 1156K sleep 0:01 0.00% 0.00% sshd
108 root 2 0 132K 472K sleep 0:01 0.00% 0.00% syslogd
22597 jrf 28 0 156K 616K onproc 0:00 0.00% 0.00% top
22592 jrf 18 0 828K 1128K sleep 0:00 0.00% 0.00% tcsh
203 root 10 0 220K 424K sleep 0:00 0.00% 0.00% cron
1 root 10 0 312K 192K sleep 0:00 0.00% 0.00% init
205 root 3 0 48K 432K sleep 0:00 0.00% 0.00% getty
206 root 3 0 48K 424K sleep 0:00 0.00% 0.00% getty
208 root 3 0 48K 424K sleep 0:00 0.00% 0.00% getty
207 root 3 0 48K 424K sleep 0:00 0.00% 0.00% getty
13667 nobody 2 0 1660K 1508K sleep 0:00 0.00% 0.00% httpd
9926 root 2 0 336K 588K sleep 0:00 0.00% 0.00% sshd
200 root 2 0 76K 456K sleep 0:00 0.00% 0.00% inetd
182 root 2 0 92K 436K sleep 0:00 0.00% 0.00% portsentry
180 root 2 0 92K 436K sleep 0:00 0.00% 0.00% portsentry
13666 nobody -4 0 1600K 1260K sleep 0:00 0.00% 0.00% httpd
The top utility is great for finding CPU hogs, runaway processes or groups of
processes that may be causing problems. The output shown above indicates that
this particular system is in good health. Now, the next display should show
some very different results:
load averages: 0.34, 0.16, 0.13 21:13:47
25 processes: 24 sleeping, 1 on processor
CPU states: 0.5% user, 0.0% nice, 9.0% system, 1.0% interrupt, 89.6% idle
Memory: 20M Act, 1712K Inact, 240K Wired, 30M Free, 129M Swap free
PID USERNAME PRI NICE SIZE RES STATE TIME WCPU CPU COMMAND
5304 jrf -5 0 56K 336K sleep 0:04 66.07% 19.53% bonnie
5294 root 2 0 412K 1176K sleep 0:02 1.01% 0.93% sshd
108 root 2 0 132K 472K sleep 1:23 0.00% 0.00% syslogd
187 root 2 0 1552K 1824K sleep 0:07 0.00% 0.00% httpd
5288 root 2 0 412K 1176K sleep 0:02 0.00% 0.00% sshd
5302 jrf 28 0 160K 620K onproc 0:00 0.00% 0.00% top
5295 jrf 18 0 828K 1116K sleep 0:00 0.00% 0.00% tcsh
5289 jrf 18 0 828K 1112K sleep 0:00 0.00% 0.00% tcsh
127 root 10 0 129M 8388K sleep 0:00 0.00% 0.00% mount_mfs
204 root 10 0 220K 424K sleep 0:00 0.00% 0.00% cron
1 root 10 0 312K 192K sleep 0:00 0.00% 0.00% init
208 root 3 0 48K 432K sleep 0:00 0.00% 0.00% getty
210 root 3 0 48K 424K sleep 0:00 0.00% 0.00% getty
209 root 3 0 48K 424K sleep 0:00 0.00% 0.00% getty
211 root 3 0 48K 424K sleep 0:00 0.00% 0.00% getty
217 nobody 2 0 1616K 1272K sleep 0:00 0.00% 0.00% httpd
184 root 2 0 336K 580K sleep 0:00 0.00% 0.00% sshd
201 root 2 0 76K 456K sleep 0:00 0.00% 0.00% inetd
At first, it should seem rather obvious which process is hogging the system,
however, what is interesting in this case is why. The bonnie program is a disk
benchmark tool which can write large files in a variety of sizes and ways. What
the previous output indicates is only that the bonnie program is a CPU hog, but
not why.
20.3.1.1. Ïther Neat Things About Top
A careful examination of the manual page top(1) shows that there is a lot more
that can be done with top, for example, processes can have their priority
changed and killed. Additionally, filters can be set for looking at processes.
20.3.2. Ôhe sysstat utility
As the man page sysstat(1) indicates, the sysstat utility shows a variety of
system statistics using the curses library. While it is running the screen is
shown in two parts, the upper window shows the current load average while the
lower screen depends on user commands. The exception to the split window view
is when vmstat display is on which takes up the whole screen. Following is what
sysstat looks like on a fairly idle system with no arguments given when it was
invoked:
/0 /1 /2 /3 /4 /5 /6 /7 /8 /9 /10
Load Average |
/0 /10 /20 /30 /40 /50 /60 /70 /80 /90 /100
<idle> XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Basically a lot of dead time there, so now have a look with some arguments
provided, in this case, sysstat inet.tcp which looks like this:
/0 /1 /2 /3 /4 /5 /6 /7 /8 /9 /10
Load Average |
0 connections initiated 19 total TCP packets sent
0 connections accepted 11 data
0 connections established 0 data (retransmit)
8 ack-only
0 connections dropped 0 window probes
0 in embryonic state 0 window updates
0 on retransmit timeout 0 urgent data only
0 by keepalive 0 control
0 by persist
29 total TCP packets received
11 potential rtt updates 17 in sequence
11 successful rtt updates 0 completely duplicate
9 delayed acks sent 0 with some duplicate data
0 retransmit timeouts 4 out of order
0 persist timeouts 0 duplicate acks
0 keepalive probes 11 acks
0 keepalive timeouts 0 window probes
0 window updates
Now that is informative. The first poll is accumulative, so it is possible to
see quite a lot of information in the output when sysstat is invoked. Now,
while that may be interesting, how about a look at the buffer cache with
sysstat bufcache:
/0 /1 /2 /3 /4 /5 /6 /7 /8 /9 /10
Load Average
There are 1642 buffers using 6568 kBytes of memory.
File System Bufs used % kB in use % Bufsize kB % Util %
/ 877 53 6171 93 6516 99 94
/var/tmp 5 0 17 0 28 0 60
Total: 882 53 6188 94 6544 99
Again, a pretty boring system, but great information to have available. While
this is all nice to look at, it is time to put a false load on the system to
see how sysstat can be used as a performance monitoring tool. As with top,
bonnie++ will be used to put a high load on the I/O subsystems and a little on
the CPU. The bufcache will be looked at again to see of there are any
noticeable differences:
/0 /1 /2 /3 /4 /5 /6 /7 /8 /9 /10
Load Average |||
There are 1642 buffers using 6568 kBytes of memory.
File System Bufs used % kB in use % Bufsize kB % Util %
/ 811 49 6422 97 6444 98 99
Total: 811 49 6422 97 6444 98
First, notice that the load average shot up, this is to be expected of course,
then, while most of the numbers are close, notice that utilization is at 99%.
Throughout the time that bonnie++ was running the utilization percentage
remained at 99, this of course makes sense, however, in a real troubleshooting
situation, it could be indicative of a process doing heavy I/O on one
particular file or filesystem.
20.4. Íonitoring Tools
In addition to screen oriented monitors and tools, the NetBSD system also ships
with a set of command line oriented tools. Many of the tools that ship with a
NetBSD system can be found on other UNIX and UNIX-like systems.
20.4.1. æstat
The fstat(1) utility reports the status of open files on the system, while it
is not what many administrators consider a performance monitor, it can help
find out if a particular user or process is using an inordinate amount of
files, generating large files and similar information.
Following is a sample of some fstat output:
USER CMD PID FD MOUNT INUM MODE SZ|DV R/W
jrf tcsh 21607 wd / 29772 drwxr-xr-x 512 r
jrf tcsh 21607 3* unix stream c057acc0<-> c0553280
jrf tcsh 21607 4* unix stream c0553280 <-> c057acc0
root sshd 21597 wd / 2 drwxr-xr-x 512 r
root sshd 21597 0 / 11921 crw-rw-rw- null rw
nobody httpd 5032 wd / 2 drwxr-xr-x 512 r
nobody httpd 5032 0 / 11921 crw-rw-rw- null r
nobody httpd 5032 1 / 11921 crw-rw-rw- null w
nobody httpd 5032 2 / 15890 -rw-r--r-- 353533 rw
...
The fields are pretty self explanatory, again, this tool while not as
performance oriented as others, can come in handy when trying to find out
information about file usage.
20.4.2. éostat
The iostat(8) command does exactly what it sounds like, it reports the status
of the I/O subsystems on the system. When iostat is employed, the user
typically runs it with a certain number of counts and an interval between them
like so:
$ iostat 5 5
tty wd0 cd0 fd0 md0 cpu
tin tout KB/t t/s MB/s KB/t t/s MB/s KB/t t/s MB/s KB/t t/s MB/s us ni sy in id
0 1 5.13 1 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100
0 54 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100
0 18 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100
0 18 8.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100
0 28 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100
The above output is from a very quiet ftp server. The fields represent the
various I/O devices, the tty (which, ironically, is the most active because
iostat is running), wd0 which is the primary IDE disk, cd0, the cdrom drive,
fd0, the floppy and the memory filesystem.
Now, let's see if we can pummel the system with some heavy usage. First, a
large ftp transaction consisting of a tarball of netbsd-current source along
with the bonnie++ disk benchmark program running at the same time.
$ iostat 5 5
tty wd0 cd0 fd0 md0 cpu
tin tout KB/t t/s MB/s KB/t t/s MB/s KB/t t/s MB/s KB/t t/s MB/s us ni sy in id
0 1 5.68 1 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100
0 54 61.03 150 8.92 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 1 0 18 4 78
0 26 63.14 157 9.71 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 1 0 20 4 75
0 20 43.58 26 1.12 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 9 2 88
0 28 19.49 82 1.55 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 1 0 7 3 89
As can be expected, notice that wd0 is very active, what is interesting about
this output is how the processor's I/O seems to rise in proportion to wd0. This
makes perfect sense, however, it is worth noting that only because this ftp
server is hardly being used can that be observed. If, for example, the cpu I/O
subsystem was already under a moderate load and the disk subsystem was under
the same load as it is now, it could appear that the cpu is bottlenecked when
in fact it would have been the disk. In such a case, we can observe that "one
tool" is rarely enough to completely analyze a problem. A quick glance at
processes probably would tell us (after watching iostat) which processes were
causing problems.
20.4.3. ðs
Using the ps(1) command or process status, a great deal of information about
the system can be discovered. Most of the time, the ps command is used to
isolate a particular process by name, group, owner etc. Invoked with no options
or arguments, ps simply prints out information about the user executing it.
$ ps
PID TT STAT TIME COMMAND
21560 p0 Is 0:00.04 -tcsh
21564 p0 I+ 0:00.37 ssh jrf.odpn.net
21598 p1 Ss 0:00.12 -tcsh
21673 p1 R+ 0:00.00 ps
21638 p2 Is+ 0:00.06 -tcsh
Not very exciting. The fields are self explanatory with the exception of STAT
which is actually the state a process is in. The flags are all documented in
the man page, however, in the above example, I is idle, S is sleeping, R is
runnable, the + means the process is in a foreground state, and the s means the
process is a session leader. This all makes perfect sense when looking at the
flags, for example, PID 21560 is a shell, it is idle and (as would be expected)
the shell is the process leader.
In most cases, someone is looking for something very specific in the process
listing. As an example, looking at all processes is specified with -a, to see
all processes plus those without controlling terminals is -ax and to get a much
more verbose listing (basically everything plus information about the impact
processes are having) aux:
# ps aux
USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND
root 0 0.0 9.6 0 6260 ?? DLs 16Jul02 0:01.00 (swapper)
root 23362 0.0 0.8 144 488 ?? S 12:38PM 0:00.01 ftpd -l
root 23328 0.0 0.4 428 280 p1 S 12:34PM 0:00.04 -csh
jrf 23312 0.0 1.8 828 1132 p1 Is 12:32PM 0:00.06 -tcsh
root 23311 0.0 1.8 388 1156 ?? S 12:32PM 0:01.60 sshd: jrf@ttyp1
jrf 21951 0.0 1.7 244 1124 p0 S+ 4:22PM 0:02.90 ssh jrf.odpn.net
jrf 21947 0.0 1.7 828 1128 p0 Is 4:21PM 0:00.04 -tcsh
root 21946 0.0 1.8 388 1156 ?? S 4:21PM 0:04.94 sshd: jrf@ttyp0
nobody 5032 0.0 2.0 1616 1300 ?? I 19Jul02 0:00.02 /usr/pkg/sbin/httpd
...
Again, most of the fields are self explanatory with the exception of VSZ and
RSS which can be a little confusing. RSS is the real size of a process in 1024
byte units while VSZ is the virtual size. This is all great, but again, how can
ps help? Well, for one, take a look at this modified version of the same
output:
# ps aux
USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND
root 0 0.0 9.6 0 6260 ?? DLs 16Jul02 0:01.00 (swapper)
root 23362 0.0 0.8 144 488 ?? S 12:38PM 0:00.01 ftpd -l
root 23328 0.0 0.4 428 280 p1 S 12:34PM 0:00.04 -csh
jrf 23312 0.0 1.8 828 1132 p1 Is 12:32PM 0:00.06 -tcsh
root 23311 0.0 1.8 388 1156 ?? S 12:32PM 0:01.60 sshd: jrf@ttyp1
jrf 21951 0.0 1.7 244 1124 p0 S+ 4:22PM 0:02.90 ssh jrf.odpn.net
jrf 21947 0.0 1.7 828 1128 p0 Is 4:21PM 0:00.04 -tcsh
root 21946 0.0 1.8 388 1156 ?? S 4:21PM 0:04.94 sshd: jrf@ttyp0
nobody 5032 9.0 2.0 1616 1300 ?? I 19Jul02 0:00.02 /usr/pkg/sbin/httpd
...
Given that on this server, our baseline indicates a relatively quiet system,
the PID 5032 has an unusually large amount of %CPU. Sometimes this can also
cause high TIME numbers. The ps command can be grepped on for PIDs, username
and process name and hence help track down processes that may be experiencing
problems.
20.4.4. ömstat
Using vmstat(1), information pertaining to virtual memory can be monitored and
measured. Not unlike iostat, vmstat can be invoked with a count and interval.
Following is some sample output using 5 5 like the iostat example:
# vmstat 5 5
procs memory page disks faults cpu
r b w avm fre flt re pi po fr sr w0 c0 f0 m0 in sy cs us sy id
0 7 0 17716 33160 2 0 0 0 0 0 1 0 0 0 105 15 4 0 0 100
0 7 0 17724 33156 2 0 0 0 0 0 1 0 0 0 109 6 3 0 0 100
0 7 0 17724 33156 1 0 0 0 0 0 1 0 0 0 105 6 3 0 0 100
0 7 0 17724 33156 1 0 0 0 0 0 0 0 0 0 107 6 3 0 0 100
0 7 0 17724 33156 1 0 0 0 0 0 0 0 0 0 105 6 3 0 0 100
Yet again, relatively quiet, for posterity, the exact same load that was put on
this server in the iostat example will be used. The load is a large file
transfer and the bonnie benchmark program.
# vmstat 5 5
procs memory page disks faults cpu
r b w avm fre flt re pi po fr sr w0 c0 f0 m0 in sy cs us sy id
1 8 0 18880 31968 2 0 0 0 0 0 1 0 0 0 105 15 4 0 0 100
0 8 0 18888 31964 2 0 0 0 0 0 130 0 0 0 1804 5539 1094 31 22 47
1 7 0 18888 31964 1 0 0 0 0 0 130 0 0 0 1802 5500 1060 36 16 49
1 8 0 18888 31964 1 0 0 0 0 0 160 0 0 0 1849 5905 1107 21 22 57
1 7 0 18888 31964 1 0 0 0 0 0 175 0 0 0 1893 6167 1082 1 25 75
Just a little different. Notice, since most of the work was I/O based, the
actual memory used was not very much. Since this system uses mfs for /tmp,
however, it can certainly get beat up. Have a look at this:
# vmstat 5 5
procs memory page disks faults cpu
r b w avm fre flt re pi po fr sr w0 c0 f0 m0 in sy cs us sy id
0 2 0 99188 500 2 0 0 0 0 0 1 0 0 0 105 16 4 0 0 100
0 2 0111596 436 592 0 587 624 586 1210 624 0 0 0 741 883 1088 0 11 89
0 3 0123976 784 666 0 662 643 683 1326 702 0 0 0 828 993 1237 0 12 88
0 2 0134692 1236 581 0 571 563 595 1158 599 0 0 0 722 863 1066 0 9 90
2 0 0142860 912 433 0 406 403 405 808 429 0 0 0 552 602 768 0 7 93
Pretty scary stuff. That was created by running bonnie in /tmp on a memory
based filesystem. If it continued for too long, it is possible the system could
have started thrashing. Notice that even though the VM subsystem was taking a
beating, the processors still were not getting too battered.
20.5. Îetwork Tools
Sometimes a performance problem is not a particular machine, it is the network
or some sort of device on the network such as another host, a router etc. What
other machines that provide a service or some sort of connectivity to a
particular NetBSD system do and how they act can have a very large impact on
performance of the NetBSD system itself, or the perception of performance by
users. A really great example of this is when a DNS server that a NetBSD
machine is using suddenly disappears. Lookups take long and they eventually
fail. Someone logged into the NetBSD machine who is not experienced would
undoubtedly (provided they had no other evidence) blame the NetBSD system. One
of my personal favorites, "the Internet is broke" usually means either DNS
service or a router/gateway has dropped offline. Whatever the case may be, a
NetBSD system comes adequately armed to deal with finding out what network
issues may be cropping up whether the fault of the local system or some other
issue.
20.5.1. ðing
The classic ping(8) utility can tell us if there is just plain connectivity, it
can also tell if host resolution (depending on how nsswitch.conf dictates) is
working. Following is some typical ping output on a local network with a count
of 3 specified:
# ping -c 3 marie
PING marie (172.16.14.12): 56 data bytes
64 bytes from 172.16.14.12: icmp_seq=0 ttl=255 time=0.571 ms
64 bytes from 172.16.14.12: icmp_seq=1 ttl=255 time=0.361 ms
64 bytes from 172.16.14.12: icmp_seq=2 ttl=255 time=0.371 ms
----marie PING Statistics----
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.361/0.434/0.571/0.118 ms
Not only does ping tell us if a host is alive, it tells us how long it took and
gives some nice details at the very end. If a host cannot be resolved, just the
IP address can be specified as well:
# ping -c 1 172.16.20.5
PING ash (172.16.20.5): 56 data bytes
64 bytes from 172.16.20.5: icmp_seq=0 ttl=64 time=0.452 ms
----ash PING Statistics----
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.452/0.452/0.452/0.000 ms
Now, not unlike any other tool, the times are very subjective, especially in
regards to networking. For example, while the times in the examples are good,
take a look at the localhost ping:
# ping -c 4 localhost
PING localhost (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=0.091 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=255 time=0.129 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=255 time=0.120 ms
64 bytes from 127.0.0.1: icmp_seq=3 ttl=255 time=0.122 ms
----localhost PING Statistics----
4 packets transmitted, 4 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.091/0.115/0.129/0.017 ms
Much smaller because the request never left the machine. Pings can be used to
gather information about how well a network is performing. It is also good for
problem isolation, for instance, if there are three relatively close in size
NetBSD systems on a network and one of them simply has horrible ping times,
chances are something is wrong on that one particular machine.
20.5.2. ôraceroute
The traceroute(8) command is great for making sure a path is available or
detecting problems on a particular path. As an example, here is a trace between
the example ftp server and ftp.NetBSD.org:
# traceroute ftp.NetBSD.org
traceroute to ftp.NetBSD.org (204.152.184.75), 30 hops max, 40 byte packets
1 208.44.95.1 (208.44.95.1) 1.646 ms 1.492 ms 1.456 ms
2 63.144.65.170 (63.144.65.170) 7.318 ms 3.249 ms 3.854 ms
3 chcg01-edge18.il.inet.qwest.net (65.113.85.229) 35.982 ms 28.667 ms 21.971 ms
4 chcg01-core01.il.inet.qwest.net (205.171.20.1) 22.607 ms 26.242 ms 19.631 ms
5 snva01-core01.ca.inet.qwest.net (205.171.8.50) 78.586 ms 70.585 ms 84.779 ms
6 snva01-core03.ca.inet.qwest.net (205.171.14.122) 69.222 ms 85.739 ms 75.979 ms
7 paix01-brdr02.ca.inet.qwest.net (205.171.205.30) 83.882 ms 67.739 ms 69.937 ms
8 198.32.175.3 (198.32.175.3) 72.782 ms 67.687 ms 73.320 ms
9 so-1-0-0.orpa8.pf.isc.org (192.5.4.231) 78.007 ms 81.860 ms 77.069 ms
10 tun0.orrc5.pf.isc.org (192.5.4.165) 70.808 ms 75.151 ms 81.485 ms
11 ftp.NetBSD.org (204.152.184.75) 69.700 ms 69.528 ms 77.788 ms
All in all, not bad. The trace went from the host to the local router, then out
onto the provider network and finally out onto the Internet looking for the
final destination. How to interpret traceroutes, again, are subjective, but
abnormally high times in portions of a path can indicate a bottleneck on a
piece of network equipment. Not unlike ping, if the host itself is suspect, run
traceroute from another host to the same destination. Now, for the worst case
scenario:
# traceroute www.microsoft.com
traceroute: Warning: www.microsoft.com has multiple addresses; using 207.46.230.220
traceroute to www.microsoft.akadns.net (207.46.230.220), 30 hops max, 40 byte packets
1 208.44.95.1 (208.44.95.1) 2.517 ms 4.922 ms 5.987 ms
2 63.144.65.170 (63.144.65.170) 10.981 ms 3.374 ms 3.249 ms
3 chcg01-edge18.il.inet.qwest.net (65.113.85.229) 37.810 ms 37.505 ms 20.795 ms
4 chcg01-core03.il.inet.qwest.net (205.171.20.21) 36.987 ms 32.320 ms 22.430 ms
5 chcg01-brdr03.il.inet.qwest.net (205.171.20.142) 33.155 ms 32.859 ms 33.462 ms
6 205.171.1.162 (205.171.1.162) 39.265 ms 20.482 ms 26.084 ms
7 sl-bb24-chi-13-0.sprintlink.net (144.232.26.85) 26.681 ms 24.000 ms 28.975 ms
8 sl-bb21-sea-10-0.sprintlink.net (144.232.20.30) 65.329 ms 69.694 ms 76.704 ms
9 sl-bb21-tac-9-1.sprintlink.net (144.232.9.221) 65.659 ms 66.797 ms 74.408 ms
10 144.232.187.194 (144.232.187.194) 104.657 ms 89.958 ms 91.754 ms
11 207.46.154.1 (207.46.154.1) 89.197 ms 84.527 ms 81.629 ms
12 207.46.155.10 (207.46.155.10) 78.090 ms 91.550 ms 89.480 ms
13 * * *
.......
In this case, the Microsoft server cannot be found either because of multiple
addresses or somewhere along the line a system or server cannot reply to the
information request. At that point, one might think to try ping, in the
Microsoft case, a ping does not reply, that is because somewhere on their
network ICMP is most likely disabled.
20.5.3. îetstat
Another problem that can crop up on a NetBSD system is routing table issues.
These issues are not always the systems fault. The route(8) and netstat(1)
commands can show information about routes and network connections
(respectively).
The route command can be used to look at and modify routing tables while
netstat can display information about network connections and routes. First,
here is some output from route show:
# route show
Routing tables
Internet:
Destination Gateway Flags
default 208.44.95.1 UG
loopback 127.0.0.1 UG
localhost 127.0.0.1 UH
172.15.13.0 172.16.14.37 UG
172.16.0.0 link#2 U
172.16.14.8 0:80:d3:cc:2c:0 UH
172.16.14.10 link#2 UH
marie 0:10:83:f9:6f:2c UH
172.16.14.37 0:5:32:8f:d2:35 UH
172.16.16.15 link#2 UH
loghost 8:0:20:a7:f0:75 UH
artemus 8:0:20:a8:d:7e UH
ash 0:b0:d0:de:49:df UH
208.44.95.0 link#1 U
208.44.95.1 0:4:27:3:94:20 UH
208.44.95.2 0:5:32:8f:d2:34 UH
208.44.95.25 0:c0:4f:10:79:92 UH
Internet6:
Destination Gateway Flags
default localhost UG
default localhost UG
localhost localhost UH
::127.0.0.0 localhost UG
::224.0.0.0 localhost UG
::255.0.0.0 localhost UG
::ffff:0.0.0.0 localhost UG
2002:: localhost UG
2002:7f00:: localhost UG
2002:e000:: localhost UG
2002:ff00:: localhost UG
fe80:: localhost UG
fe80::%ex0 link#1 U
fe80::%ex1 link#2 U
fe80::%lo0 fe80::1%lo0 U
fec0:: localhost UG
ff01:: localhost U
ff02::%ex0 link#1 U
ff02::%ex1 link#2 U
ff02::%lo0 fe80::1%lo0 U
The flags section shows the status and whether or not it is a gateway. In this
case we see U, H and G (U is up, H is host and G is gateway, see the man page
for additional flags).
Now for some netstat output using the -r (routing) and -n (show network
numbers) options:
Routing tables
Internet:
Destination Gateway Flags Refs Use Mtu Interface
default 208.44.95.1 UGS 0 330309 1500 ex0
127 127.0.0.1 UGRS 0 0 33228 lo0
127.0.0.1 127.0.0.1 UH 1 1624 33228 lo0
172.15.13/24 172.16.14.37 UGS 0 0 1500 ex1
172.16 link#2 UC 13 0 1500 ex1
...
Internet6:
Destination Gateway Flags Refs Use
Mtu Interface
::/104 ::1 UGRS 0 0
33228 lo0 =>
::/96 ::1 UGRS 0 0
The above output is a little more verbose. So, how can this help? Well, a good
example is when routes between networks get changed while users are connected.
I saw this happen several times when someone was rebooting routers all day long
after each change. Several users called up saying they were getting kicked out
and it was taking very long to log back in. As it turned out, the clients
connecting to the system were redirected to another router (which took a very
long route) to reconnect. I observed the M flag or Modified dynamically (by
redirect) on their connections. I deleted the routes, had them reconnect and
summarily followed up with the offending technician.
20.5.4. ôcpdump
Last, and definitely not least is tcpdump(8), the network sniffer that can
retrieve a lot of information. In this discussion, there will be some sample
output and an explanation of some of the more useful options of tcpdump.
Following is a small snippet of tcpdump in action just as it starts:
# tcpdump
tcpdump: listening on ex0
14:07:29.920651 mail.ssh > 208.44.95.231.3551: P 2951836801:2951836845(44) ack 2
476972923 win 17520 <nop,nop,timestamp 1219259 128519450> [tos 0x10]
14:07:29.950594 12.125.61.34 > 208.44.95.16: ESP(spi=2548773187,seq=0x3e8c) (DF)
14:07:29.983117 smtp.somecorp.com.smtp > 208.44.95.30.42828: . ack 420285166 win
16500 (DF)
14:07:29.984406 208.44.95.30.42828 > smtp.somecorp.com.smtp: . 1:1376(1375) ack 0
win 7431 (DF)
...
Given that the particular server is a mail server, what is shown makes perfect
sense, however, the utility is very verbose, I prefer to initially run tcpdump
with no options and send the text output into a file for later digestion like
so:
# tcpdump > tcpdump.out
tcpdump: listening on ex0
So, what precisely in the mish mosh are we looking for? In short, anything that
does not seem to fit, for example, messed up packet lengths (as in a lot of
them) will show up as improper lens or malformed packets (basically garbage).
If, however, we are looking for something specific, tcpdump may be able to help
depending on the problem.
20.5.4.1. Ópecific tcpdump Usage
These are just examples of a few things one can do with tcpdump.
Look for duplicate IP addresses:
tcpdump -e host ip-address
For example:
tcpdump -e host 192.168.0.2
Routing Problems:
tcpdump icmp
There are plenty of third party tools available, however, NetBSD comes shipped
with a good tool set for tracking down network level performance problems.
20.6. Áccounting
The NetBSD system comes equipped with a great deal of performance monitors for
active monitoring, but what about long term monitoring? Well, of course the
output of a variety of commands can be sent to files and re-parsed later with a
meaningful shell script or program. NetBSD does, by default, offer some
extraordinarily powerful low level monitoring tools for the programmer,
administrator or really astute hobbyist.
20.6.1. Áccounting
While accounting gives system usage at an almost userland level, kernel
profiling with gprof provides explicit system call usage.
Using the accounting tools can help figure out what possible performance
problems may be laying in wait, such as increased usage of compilers or network
services for example.
Starting accounting is actually fairly simple, as root, use the accton(8)
command. The syntax to start accounting is: accton filename
Where accounting information is appended to filename, now, strangely enough,
the lastcomm command which reads from an accounting output file, by default,
looks in /var/account/acct so I tend to just use the default location, however,
lastcomm can be told to look elsewhere.
To stop accounting, simply type accton with no arguments.
20.6.2. Òeading Accounting Information
To read accounting information, there are two tools that can be used:
* lastcomm(1)
* sa(8)
20.6.2.1. ìastcomm
The lastcomm command shows the last commands executed in order, like all of
them. It can, however, select by user, here is some sample output:
$ lastcomm jrf
last - jrf ttyp3 0.00 secs Tue Sep 3 14:39 (0:00:00.02)
man - jrf ttyp3 0.00 secs Tue Sep 3 14:38 (0:01:49.03)
sh - jrf ttyp3 0.00 secs Tue Sep 3 14:38 (0:01:49.03)
less - jrf ttyp3 0.00 secs Tue Sep 3 14:38 (0:01:49.03)
lastcomm - jrf ttyp3 0.02 secs Tue Sep 3 14:38 (0:00:00.02)
stty - jrf ttyp3 0.00 secs Tue Sep 3 14:38 (0:00:00.02)
tset - jrf ttyp3 0.00 secs Tue Sep 3 14:38 (0:00:01.05)
hostname - jrf ttyp3 0.00 secs Tue Sep 3 14:38 (0:00:00.02)
ls - jrf ttyp0 0.00 secs Tue Sep 3 14:36 (0:00:00.00)
...
Pretty nice, the lastcomm command gets its information from the default
location of /var/account/acct, however, using the -f option, another file may
be specified.
As may seem obvious, the output of lastcomm could get a little heavy on large
multi user systems. That is where sa comes into play.
20.6.2.2. óa
The sa command (meaning "print system accounting statistics") can be used to
maintain information. It can also be used interactively to create reports.
Following is the default output of sa:
$ sa
77 18.62re 0.02cp 8avio 0k
3 4.27re 0.01cp 45avio 0k ispell
2 0.68re 0.00cp 33avio 0k mutt
2 1.09re 0.00cp 23avio 0k vi
10 0.61re 0.00cp 7avio 0k ***other
2 0.01re 0.00cp 29avio 0k exim
4 0.00re 0.00cp 8avio 0k lastcomm
2 0.00re 0.00cp 3avio 0k atrun
3 0.03re 0.00cp 1avio 0k cron*
5 0.02re 0.00cp 10avio 0k exim*
10 3.98re 0.00cp 2avio 0k less
11 0.00re 0.00cp 0avio 0k ls
9 3.95re 0.00cp 12avio 0k man
2 0.00re 0.00cp 4avio 0k sa
12 3.97re 0.00cp 1avio 0k sh
...
From left to right, total times called, real time in minutes, sum of user and
system time, in minutes, Average number of I/O operations per execution, size,
command name.
The sa command can also be used to create summary files or reports based on
some options, for example, here is the output when specifying a sort by
CPU-time average memory usage:
$ sa -k
86 30.81re 0.02cp 8avio 0k
10 0.61re 0.00cp 7avio 0k ***other
2 0.00re 0.00cp 3avio 0k atrun
3 0.03re 0.00cp 1avio 0k cron*
2 0.01re 0.00cp 29avio 0k exim
5 0.02re 0.00cp 10avio 0k exim*
3 4.27re 0.01cp 45avio 0k ispell
4 0.00re 0.00cp 8avio 0k lastcomm
12 8.04re 0.00cp 2avio 0k less
13 0.00re 0.00cp 0avio 0k ls
11 8.01re 0.00cp 12avio 0k man
2 0.68re 0.00cp 33avio 0k mutt
3 0.00re 0.00cp 4avio 0k sa
14 8.03re 0.00cp 1avio 0k sh
2 1.09re 0.00cp 23avio 0k vi
The sa command is very helpful on larger systems.
20.6.3. Èow to Put Accounting to Use
Accounting reports, as was mentioned earlier, offer a way to help predict
trends, for example, on a system that has cc and make being used more and more
may indicate that in a few months some changes will need to be made to keep the
system running at an optimum level. Another good example is web server usage.
If it begins to gradually increase, again, some sort of action may need to be
taken before it becomes a problem. Luckily, with accounting tools, said actions
can be reasonably predicted and planned for ahead of time.
20.7. Ëernel Profiling
Profiling a kernel is normally employed when the goal is to compare the
difference of new changes in the kernel to a previous one or to track down some
sort of low level performance problem. Two sets of data about profiled code
behavior are recorded independently: function call frequency and time spent in
each function.
20.7.1. Çetting Started
First, take a look at both Section0.9, "Kernel Tuning" and Chapter4,
Compiling the kernel. The only difference in procedure for setting up a kernel
with profiling enabled is when you run config add the -p option. The build area
is ../compile/<KERNEL_NAME>.PROF , for example, a GENERIC kernel would be ../
compile/GENERIC.PROF.
Following is a quick summary of how to compile a kernel with profiling enabled
on the amd64 port, the assumptions are that the appropriate sources are
available under /usr/src and the GENERIC configuration is being used, of
course, that may not always be the situation:
1. cd /usr/src/sys/arch/amd64/conf
2. config -p GENERIC
3. cd ../compile/GENERIC.PROF
4. make depend && make
5. cp /netbsd /netbsd.old
6. cp netbsd /
7. reboot
Once the new kernel is in place and the system has rebooted, it is time to turn
on the monitoring and start looking at results.
20.7.1.1. Õsing kgmon
To start kgmon:
$ kgmon -b
kgmon: kernel profiling is running.
Next, send the data into the file gmon.out:
$ kgmon -p
Now, it is time to make the output readable:
$ gprof /netbsd > gprof.out
Since gmon is looking for gmon.out, it should find it in the current working
directory.
By just running kgmon alone, you may not get the information you need, however,
if you are comparing the differences between two different kernels, then a
known good baseline should be used. Note that it is generally a good idea to
stress the subsystem if you know what it is both in the baseline and with the
newer (or different) kernel.
20.7.2. Énterpretation of kgmon Output
Now that kgmon can run, collect and parse information, it is time to actually
look at some of that information. In this particular instance, a GENERIC kernel
is running with profiling enabled for about an hour with only system processes
and no adverse load, in the fault insertion section, the example will be large
enough that even under a minimal load detection of the problem should be easy.
20.7.2.1. Ælat Profile
The flat profile is a list of functions, the number of times they were called
and how long it took (in seconds). Following is sample output from the quiet
system:
Flat profile:
Each sample counts as 0.01 seconds.
% cumulative self self total
time seconds seconds calls ns/call ns/call name
99.77 163.87 163.87 idle
0.03 163.92 0.05 219 228310.50 228354.34 _wdc_ata_bio_start
0.02 163.96 0.04 219 182648.40 391184.96 wdc_ata_bio_intr
0.01 163.98 0.02 3412 5861.66 6463.02 pmap_enter
0.01 164.00 0.02 548 36496.35 36496.35 pmap_zero_page
0.01 164.02 0.02 Xspllower
0.01 164.03 0.01 481968 20.75 20.75 gettick
0.01 164.04 0.01 6695 1493.65 1493.65 VOP_LOCK
0.01 164.05 0.01 3251 3075.98 21013.45 syscall_plain
...
As expected, idle was the highest in percentage, however, there were still some
things going on, for example, a little further down there is the vn_lock
function:
...
0.00 164.14 0.00 6711 0.00 0.00 VOP_UNLOCK
0.00 164.14 0.00 6677 0.00 1493.65 vn_lock
0.00 164.14 0.00 6441 0.00 0.00 genfs_unlock
This is to be expected, since locking still has to take place, regardless.
20.7.2.2. Ãall Graph Profile
The call graph is an augmented version of the flat profile showing subsequent
calls from the listed functions. First, here is some sample output:
Call graph (explanation follows)
granularity: each sample hit covers 4 byte(s) for 0.01% of 164.14 seconds
index % time self children called name
<spontaneous>
[1] 99.8 163.87 0.00 idle [1]
-----------------------------------------------
<spontaneous>
[2] 0.1 0.01 0.08 syscall1 [2]
0.01 0.06 3251/3251 syscall_plain [7]
0.00 0.01 414/1660 trap [9]
-----------------------------------------------
0.00 0.09 219/219 Xintr14 [6]
[3] 0.1 0.00 0.09 219 pciide_compat_intr [3]
0.00 0.09 219/219 wdcintr [5]
-----------------------------------------------
...
Now this can be a little confusing. The index number is mapped to from the
trailing number on the end of the line, for example,
...
0.00 0.01 85/85 dofilewrite [68]
[72] 0.0 0.00 0.01 85 soo_write [72]
0.00 0.01 85/89 sosend [71]
...
Here we see that dofilewrite was called first, now we can look at the index
number for 64 and see what was happening there:
...
0.00 0.01 101/103 ffs_full_fsync <cycle 6> [58]
[64] 0.0 0.00 0.01 103 bawrite [64]
0.00 0.01 103/105 VOP_BWRITE [60]
...
And so on, in this way, a "visual trace" can be established.
At the end of the call graph right after the terms section is an index by
function name which can help map indexes as well.
20.7.3. Ðutting it to Use
In this example, I have modified an area of the kernel I know will create a
problem that will be blatantly obvious.
Here is the top portion of the flat profile after running the system for about
an hour with little interaction from users:
Flat profile:
Each sample counts as 0.01 seconds.
% cumulative self self total
time seconds seconds calls us/call us/call name
93.97 139.13 139.13 idle
5.87 147.82 8.69 23 377826.09 377842.52 check_exec
0.01 147.84 0.02 243 82.30 82.30 pmap_copy_page
0.01 147.86 0.02 131 152.67 152.67 _wdc_ata_bio_start
0.01 147.88 0.02 131 152.67 271.85 wdc_ata_bio_intr
0.01 147.89 0.01 4428 2.26 2.66 uvn_findpage
0.01 147.90 0.01 4145 2.41 2.41 uvm_pageactivate
0.01 147.91 0.01 2473 4.04 3532.40 syscall_plain
0.01 147.92 0.01 1717 5.82 5.82 i486_copyout
0.01 147.93 0.01 1430 6.99 56.52 uvm_fault
0.01 147.94 0.01 1309 7.64 7.64 pool_get
0.01 147.95 0.01 673 14.86 38.43 genfs_getpages
0.01 147.96 0.01 498 20.08 20.08 pmap_zero_page
0.01 147.97 0.01 219 45.66 46.28 uvm_unmap_remove
0.01 147.98 0.01 111 90.09 90.09 selscan
...
As is obvious, there is a large difference in performance. Right off the bat
the idle time is noticeably less. The main difference here is that one
particular function has a large time across the board with very few calls. That
function is check_exec. While at first, this may not seem strange if a lot of
commands had been executed, when compared to the flat profile of the first
measurement, proportionally it does not seem right:
...
0.00 164.14 0.00 37 0.00 62747.49 check_exec
...
The call in the first measurement is made 37 times and has a better
performance. Obviously something in or around that function is wrong. To
eliminate other functions, a look at the call graph can help, here is the first
instance of check_exec
...
-----------------------------------------------
0.00 8.69 23/23 syscall_plain [3]
[4] 5.9 0.00 8.69 23 sys_execve [4]
8.69 0.00 23/23 check_exec [5]
0.00 0.00 20/20 elf32_copyargs [67]
...
Notice how the time of 8.69 seems to affect the two previous functions. It is
possible that there is something wrong with them, however, the next instance of
check_exec seems to prove otherwise:
...
-----------------------------------------------
8.69 0.00 23/23 sys_execve [4]
[5] 5.9 8.69 0.00 23 check_exec [5]
...
Now we can see that the problem, most likely, resides in check_exec. Of course,
problems are not always this simple and in fact, here is the simpleton code
that was inserted right after check_exec (the function is in sys/kern/
kern_exec.c):
...
/* A Cheap fault insertion */
for (x = 0; x < 100000000; x++) {
y = x;
}
..
Not exactly glamorous, but enough to register a large change with profiling.
20.7.4. Óummary
Kernel profiling can be enlightening for anyone and provides a much more
refined method of hunting down performance problems that are not as easy to
find using conventional means, it is also not nearly as hard as most people
think, if you can compile a kernel, you can get profiling to work.
20.8. Óystem Tuning
Now that monitoring and analysis tools have been addressed, it is time to look
into some actual methods. In this section, tools and methods that can affect
how the system performs that are applied without recompiling the kernel are
addressed, the next section examines kernel tuning by recompiling.
20.8.1. Õsing sysctl
The sysctl utility can be used to look at and in some cases alter system
parameters. There are so many parameters that can be viewed and changed they
cannot all be shown here, however, for the first example here is a simple usage
of sysctl to look at the system PATH environment variable:
$ sysctl user.cs_path
user.cs_path = /usr/bin:/bin:/usr/sbin:/sbin:/usr/pkg/bin:/usr/pkg/sbin:/usr/local/bin:/usr/local/sbin
Fairly simple. Now something that is actually related to performance. As an
example, lets say a system with many users is having file open issues, by
examining and perhaps raising the kern.maxfiles parameter the problem may be
fixed, but first, a look:
$ sysctl kern.maxfiles
kern.maxfiles = 1772
Now, to change it, as root with the -w option specified:
# sysctl -w kern.maxfiles=1972
kern.maxfiles: 1772 -> 1972
Note, when the system is rebooted, the old value will return, there are two
cures for this, first, modify that parameter in the kernel and recompile,
second (and simpler) add this line to /etc/sysctl.conf:
kern.maxfiles=1972
20.8.2. ômpfs & mfs
NetBSD's "ramdisk" implementations cache all data in the RAM, and if that is
full, the swap space is used as backing store. NetBSD comes with two
implementations, the traditional BSD memory-based file system "mfs" and the
more modern "tmpfs". While the former can only grow in size, the latter can
also shrink if space is no longer needed.
When to use and not to use a memory based filesystem can be hard on large multi
user systems. In some cases, however, it makes pretty good sense, for example,
on a development machine used by only one developer at a time, the obj
directory might be a good place, or some of the tmp directories for builds. In
a case like that, it makes sense on machines that have a fair amount of RAM on
them. On the other side of the coin, if a system only has 16MB of RAM and /var/
tmp is mfs-based, there could be severe applications issues that occur.
The GENERIC kernel has both tmpfs and mfs enabled by default. To use it on a
particular directory first determine where the swap space is that you wish to
use, in the example case, a quick look in /etc/fstab indicates that /dev/wd0b
is the swap partition:
mail% cat /etc/fstab
/dev/wd0a / ffs rw 1 1
/dev/wd0b none swap sw 0 0
/kern /kern kernfs rw
This system is a mail server so I only want to use /tmp with tmpfs, also on
this particular system I have linked /tmp to /var/tmp to save space (they are
on the same drive). All I need to do is add the following entry:
/dev/wd0b /var/tmp tmpfs rw 0 0
If you want to use "mfs" instead of "tmpfs", put just that into the above
place.
Now, a word of warning: make sure said directories are empty and nothing is
using them when you mount the memory file system! After changing /etc/fstab,
you can either run mount -a or reboot the system.
20.8.3. Êournaling
Journaling is a mechanism which puts written data in a so-called "journal"
first, and in a second step the data from the journal is written to disk. In
the event of a system crash, data that was not written to disk but that is in
the journal can be replayed, and will thus get the disk into a proper state.
The main effect of this is that no file system check (fsck) is needed after a
rough reboot.
Journaling can be enabled by adding "log" to the filesystem options in /etc/
fstab. Here is an example which enables journaling for the root (/), /var, and
/usr file systems:
/dev/wd0a / ffs rw,log 1 1
/dev/wd0e /var ffs rw,log 1 2
/dev/wd0g /usr ffs rw,log 1 2
20.8.4. ÌFS
LFS, the log structured filesystem, writes data to disk in a way that is
sometimes too aggressive and leads to congestion. To throttle writing, the
following sysctls can be used:
vfs.sync.delay
vfs.sync.filedelay
vfs.sync.dirdelay
vfs.sync.metadelay
vfs.lfs.flushindir
vfs.lfs.clean_vnhead
vfs.lfs.dostats
vfs.lfs.pagetrip
vfs.lfs.stats.segsused
vfs.lfs.stats.psegwrites
vfs.lfs.stats.psyncwrites
vfs.lfs.stats.pcleanwrites
vfs.lfs.stats.blocktot
vfs.lfs.stats.cleanblocks
vfs.lfs.stats.ncheckpoints
vfs.lfs.stats.nwrites
vfs.lfs.stats.nsync_writes
vfs.lfs.stats.wait_exceeded
vfs.lfs.stats.write_exceeded
vfs.lfs.stats.flush_invoked
vfs.lfs.stats.vflush_invoked
vfs.lfs.stats.clean_inlocked
vfs.lfs.stats.clean_vnlocked
vfs.lfs.stats.segs_reclaimed
vfs.lfs.ignore_lazy_sync
Besides tuning those parameters, disabling write-back caching on wd(4) devices
may be beneficial. See the dkctl(8) man page for details.
More is available in the NetBSD mailing list archives. See this and this mail.
20.9. Ëernel Tuning
While many system parameters can be changed with sysctl, many improvements by
using enhanced system software, layout of the system and managing services
(moving them in and out of inetd for example) can be achieved as well. Tuning
the kernel however will provide better performance, even if it appears to be
marginal.
20.9.1. Ðreparing to Recompile a Kernel
First, get the kernel sources for the release as described in Chapter2,
Obtaining the sources, reading Chapter4, Compiling the kernel for more
information on building the kernel is recommended. Note, this document can be
used for -current tuning, however, a read of the Tracking -current
documentation should be done first, much of the information there is repeated
here.
20.9.2. Ãonfiguring the Kernel
Configuring a kernel in NetBSD can be daunting. This is because of multiple
line dependencies within the configuration file itself, however, there is a
benefit to this method and that is, all it really takes is an ASCII editor to
get a new kernel configured and some dmesg output. The kernel configuration
file is under src/sys/arch/ARCH/conf where ARCH is your architecture (for
example, on a SPARC it would be under src/sys/arch/sparc/conf).
After you have located your kernel config file, copy it and remove (comment
out) all the entries you don't need. This is where dmesg(8) becomes your
friend. A clean dmesg(8)-output will show all of the devices detected by the
kernel at boot time. Using dmesg(8) output, the device options really needed
can be determined.
20.9.2.1. Óome example Configuration Items
In this example, an ftp server's kernel is being reconfigured to run with the
bare minimum drivers and options and any other items that might make it run
faster (again, not necessarily smaller, although it will be). The first thing
to do is take a look at some of the main configuration items. So, in /usr/src/
sys/arch/amd64/conf the GENERIC file is copied to FTP, then the file FTP
edited.
At the start of the file there are a bunch of options beginning with maxusers,
which will be left alone, however, on larger multi-user systems it might be
help to crank that value up a bit. Next is CPU support, looking at the dmesg
output this is seen:
cpu0: Intel Pentium II/Celeron (Deschutes) (686-class), 400.93 MHz
Indicating that only the options I686_CPU options needs to be used. In the next
section, all options are left alone except the PIC_DELAY which is recommended
unless it is an older machine. In this case it is enabled since the 686 is "
relatively new."
Between the last section all the way down to compat options there really was no
need to change anything on this particular system. In the compat section,
however, there are several options that do not need to be enabled, again this
is because this machine is strictly a FTP server, all compat options were
turned off.
The next section is File systems, and again, for this server very few need to
be on, the following were left on:
# File systems
file-system FFS # UFS
file-system LFS # log-structured file system
file-system MFS # memory file system
file-system CD9660 # ISO 9660 + Rock Ridge file system
file-system FDESC # /dev/fd
file-system KERNFS # /kern
file-system NULLFS # loopback file system
file-system PROCFS # /proc
file-system UMAPFS # NULLFS + uid and gid remapping
...
options SOFTDEP # FFS soft updates support.
...
Next comes the network options section. The only options left on were:
options INET # IP + ICMP + TCP + UDP
options INET6 # IPV6
options IPFILTER_LOG # ipmon(8) log support
IPFILTER_LOG is a nice one to have around since the server will be running ipf.
The next section is verbose messages for various subsystems, since this machine
is already running and had no major problems, all of them are commented out.
20.9.2.2. Óome Drivers
The configurable items in the config file are relatively few and easy to cover,
however, device drivers are a different story. In the following examples, two
drivers are examined and their associated "areas" in the file trimmed down.
First, a small example: the cdrom, in dmesg, is the following lines:
...
cd0 at atapibus0 drive 0: <CD-540E, , 1.0A> type 5 cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2
pciide0: secondary channel interrupting at irq 15
cd0(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfer
...
Now, it is time to track that section down in the configuration file. Notice
that the "cd"-drive is on an atapibus and requires pciide support. The section
that is of interest in this case is the kernel config's "IDE and related
devices" section. It is worth noting at this point, in and around the IDE
section are also ISA, PCMCIA etc., on this machine in the dmesg(8) output there
are no PCMCIA devices, so it stands to reason that all PCMCIA references can be
removed. But first, the "cd" drive.
At the start of the IDE section is the following:
...
wd* at atabus? drive ? flags 0x0000
...
atapibus* at atapi?
...
Well, it is pretty obvious that those lines need to be kept. Next is this:
...
# ATAPI devices
# flags have the same meaning as for IDE drives.
cd* at atapibus? drive ? flags 0x0000 # ATAPI CD-ROM drives
sd* at atapibus? drive ? flags 0x0000 # ATAPI disk drives
st* at atapibus? drive ? flags 0x0000 # ATAPI tape drives
uk* at atapibus? drive ? flags 0x0000 # ATAPI unknown
...
The only device type that was in the dmesg(8) output was the cd, the rest can
be commented out.
The next example is slightly more difficult, network interfaces. This machine
has two of them:
...
ex0 at pci0 dev 17 function 0: 3Com 3c905B-TX 10/100 Ethernet (rev. 0x64)
ex0: interrupting at irq 10
ex0: MAC address 00:50:04:83:ff:b7
UI 0x001018 model 0x0012 rev 0 at ex0 phy 24 not configured
ex1 at pci0 dev 19 function 0: 3Com 3c905B-TX 10/100 Ethernet (rev. 0x30)
ex1: interrupting at irq 11
ex1: MAC address 00:50:da:63:91:2e
exphy0 at ex1 phy 24: 3Com internal media interface
exphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
...
At first glance it may appear that there are in fact three devices, however, a
closer look at this line:
exphy0 at ex1 phy 24: 3Com internal media interface
Reveals that it is only two physical cards, not unlike the cdrom, simply
removing names that are not in dmesg will do the job. In the beginning of the
network interfaces section is:
...
# Network Interfaces
# PCI network interfaces
an* at pci? dev ? function ? # Aironet PC4500/PC4800 (802.11)
bge* at pci? dev ? function ? # Broadcom 570x gigabit Ethernet
en* at pci? dev ? function ? # ENI/Adaptec ATM
ep* at pci? dev ? function ? # 3Com 3c59x
epic* at pci? dev ? function ? # SMC EPIC/100 Ethernet
esh* at pci? dev ? function ? # Essential HIPPI card
ex* at pci? dev ? function ? # 3Com 90x[BC]
...
There is the ex device. So all of the rest under the PCI section can be
removed. Additionally, every single line all the way down to this one:
exphy* at mii? phy ? # 3Com internal PHYs
can be commented out as well as the remaining.
20.9.2.3. Íulti Pass
When I tune a kernel, I like to do it remotely in an X windows session, in one
window the dmesg output, in the other the config file. It can sometimes take a
few passes to rebuild a very trimmed kernel since it is easy to accidentally
remove dependencies.
20.9.3. Âuilding the New Kernel
Now it is time to build the kernel and put it in place. In the conf directory
on the ftp server, the following command prepares the build:
$ config FTP
When it is done a message reminding me to make depend will display, next:
$ cd ../compile/FTP
$ make depend && make
When it is done, I backup the old kernel and drop the new one in place:
# cp /netbsd /netbsd.orig
# cp netbsd /
Now reboot. If the kernel cannot boot, stop the boot process when prompted and
type boot netbsd.orig to boot from the previous kernel.
20.9.4. Óhrinking the NetBSD kernel
When building a kernel for embedded systems, it's often necessary to modify the
Kernel binary to reduce space or memory footprint.
20.9.4.1. Òemoving ELF sections and debug information
We already know how to remove Kernel support for drivers and options that you
don't need, thus saving memory and space, but you can save some KiloBytes of
space by removing debugging symbols and two ELF sections if you don't need
them: .comment and .ident. They are used for storing RCS strings viewable with
ident(1) and a gcc(1) version string. The following examples assume you have
your TOOLDIR under /usr/src/tooldir.NetBSD-2.0-i386 and the target architecture
is i386.
$ /usr/src/tooldir.NetBSD-2.0-i386/bin/i386--netbsdelf-objdump -h /netbsd
/netbsd: file format elf32-i386
Sections:
Idx Name Size VMA LMA File off Algn
0 .text 0057a374 c0100000 c0100000 00001000 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
1 .rodata 00131433 c067a380 c067a380 0057b380 2**5
CONTENTS, ALLOC, LOAD, READONLY, DATA
2 .rodata.str1.1 00035ea0 c07ab7b3 c07ab7b3 006ac7b3 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
3 .rodata.str1.32 00059d13 c07e1660 c07e1660 006e2660 2**5
CONTENTS, ALLOC, LOAD, READONLY, DATA
4 link_set_malloc_types 00000198 c083b374 c083b374 0073c374 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
5 link_set_domains 00000024 c083b50c c083b50c 0073c50c 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
6 link_set_pools 00000158 c083b530 c083b530 0073c530 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
7 link_set_sysctl_funcs 000000f0 c083b688 c083b688 0073c688 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
8 link_set_vfsops 00000044 c083b778 c083b778 0073c778 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
9 link_set_dkwedge_methods 00000004 c083b7bc c083b7bc 0073c7bc 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
10 link_set_bufq_strats 0000000c c083b7c0 c083b7c0 0073c7c0 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
11 link_set_evcnts 00000030 c083b7cc c083b7cc 0073c7cc 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
12 .data 00048ae4 c083c800 c083c800 0073c800 2**5
CONTENTS, ALLOC, LOAD, DATA
13 .bss 00058974 c0885300 c0885300 00785300 2**5
ALLOC
14 .comment 0000cda0 00000000 00000000 00785300 2**0
CONTENTS, READONLY
15 .ident 000119e4 00000000 00000000 007920a0 2**0
CONTENTS, READONLY
On the third column we can see the size of the sections in hexadecimal form. By
summing .comment and .ident sizes we know how much we're going to save with
their removal: around 120KB (= 52640 + 72164 = 0xcda0 + 0x119e4). To remove the
sections and debugging symbols that may be present, we're going to use strip(1)
:
# cp /netbsd /netbsd.orig
# /usr/src/tooldir.NetBSD-2.0-i386/bin/i386--netbsdelf-strip -S -R .ident -R .comment /netbsd
# ls -l /netbsd /netbsd.orig
-rwxr-xr-x 1 root wheel 8590668 Apr 30 15:56 netbsd
-rwxr-xr-x 1 root wheel 8757547 Apr 30 15:56 netbsd.orig
Since we also removed debugging symbols, the total amount of disk space saved
is around 160KB.
20.9.4.2. Ãompressing the Kernel
On some architectures, the bootloader can boot a compressed kernel. You can
save several MegaBytes of disk space by using this method, but the bootloader
will take longer to load the Kernel.
# cp /netbsd /netbsd.plain
# gzip -9 /netbsd
To see how much space we've saved:
$ ls -l /netbsd.plain /netbsd.gz
-rwxr-xr-x 1 root wheel 8757547 Apr 29 18:05 /netbsd.plain
-rwxr-xr-x 1 root wheel 3987769 Apr 29 18:05 /netbsd.gz
Note that you can only use gzip coding, by using gzip(1), bzip2 is not
supported by the NetBSD bootloaders!
Chapter1. ÎetBSD Veriexec subsystem
Table of Contents
21.1. How it works
21.2. Signatures file
21.3. Generating fingerprints
21.4. Strict levels
21.5. Veriexec and layered file systems
21.6. Kernel configuration
Veriexec is NetBSD's file integrity subsystem. It's kernel based, hence can
provide some protection even in the case of a root compromise.
21.1. Èow it works
Veriexec works by loading a specification file, also called the signatures file
, to the kernel. This file contains information about files Veriexec should
monitor, as well as their digital fingerprint (along with the hashing algorithm
used to produce this fingerprint), and various flags that will be discussed
later.
At the moment, the following hashing algorithms are supported by Veriexec: MD5,
SHA1, SHA256, SHA384, SHA512, and RMD160.
21.2. Óignatures file
An entry in the Veriexec signatures file looks like this:
/path/to/file algorithm fingerprint flags
Where the first element, the path, must always be an absolute path. The
algorithm is one of the algorithms listed above, and fingerprint is the ASCII
fingerprint.
21.3. Çenerating fingerprints
You can generate ASCII fingerprints for each algorithm using the following
tools:
Table1.1. Öeriexec fingerprints tools
+----------------------------------+
|Algorithm| Tool |
|---------+------------------------|
|MD5 |/usr/bin/cksum -a md5 |
|---------+------------------------|
|SHA1 |/usr/bin/cksum -a sha1 |
|---------+------------------------|
|SHA256 |/usr/bin/cksum -a sha256|
|---------+------------------------|
|SHA384 |/usr/bin/cksum -a sha384|
|---------+------------------------|
|SHA512 |/usr/bin/cksum -a sha512|
|---------+------------------------|
|RMD160 |/usr/bin/cksum -a rmd160|
+----------------------------------+
For example, to generate a MD5 fingerprint for /bin/ls:
% cksum -a md5 < /bin/ls
a8b525da46e758778564308ed9b1e493
And to generate a SHA512 fingerprint for /bin/ps:
% cksum -a sha512 < /bin/ps
381d4ad64fd47800897446a2026eca42151e03adeae158db5a34d12c529559113d928a9fef9a7c4615d257688d1da4645db004081030d7f080bb7198067eb890
Each entry may be associated with zero or more flags. Currently, these flags
indicate how the file the entry is describing should be accessed. Note that
this access type is enforced only in strict level 2 (IPS mode) and above.
The access types you can use are "DIRECT", "INDIRECT", and "FILE".
* DIRECT access means that the file is executed directly, and not invoked as
an interpreter for some script, or opened with an editor. Usually, most
programs you use will be accessed using this mode:
% ls /tmp
% cp ~/foo /tmp/bar
% rm ~/foo
* INDIRECT access means that the file is executed indirectly, and is invoked
to interpret a script. This happens usually when scripts have a #! magic as
their first line. For example, if you have a script with the following as
its first line:
#!/bin/sh
And you run it as:
% ./script.sh
Then /bin/sh will be executed indirectly -- it will be invoked to interpret
the script.
* FILE entries refer to everything which is not (or should not) be an
executable. This includes shared libraries, configuration files, etc.
Some examples for Veriexec signature file entries:
/bin/ls MD5 dc2e14dc84bdefff4bf9777958c1b20b DIRECT
/usr/bin/perl MD5 914aa8aa47ebd79ccd7909a09ed61f81 INDIRECT
/etc/pf.conf MD5 950e1dd6fcb3f27df1bf6accf7029f7d FILE
Veriexec allows you to specify more than one way to access a file in an entry.
For example, even though /usr/bin/perl is mostly used as an interpreter, it may
be desired to be able to execute it directly, too:
/usr/bin/perl MD5 914aa8aa47ebd79ccd7909a09ed61f81 DIRECT, INDIRECT
Shell scripts using #! magic to be "executable" also require two access types:
We need them to be "DIRECT" so we can execute them, and we need them to be "
FILE" so that the kernel can feed their contents to the interpreter they
define:
/usr/src/build.sh MD5 e80dbb4c047ecc1d84053174c1e9264a DIRECT, FILE
To make it easier to create signature files, and to make the signature files
themselves more readable, Veriexec allows you to use the following aliases:
Table1.2. Öeriexec access type aliases
+-------------------------+
| Alias | Expansion |
|-----------+-------------|
|PROGRAM |DIRECT |
|-----------+-------------|
|INTERPRETER|INDIRECT |
|-----------+-------------|
|SCRIPT |DIRECT, FILE |
|-----------+-------------|
|LIBRARY |FILE |
+-------------------------+
After you have generated a signatures file, you should save it as /etc/
signatures, and enable Veriexec in rc.conf:
veriexec=YES
21.4. Ótrict levels
Since different people might want to use Veriexec for different purposes, we
also define four strict levels, ranging 0-3, and named "learning", "IDS", "IPS"
, and "lockdown" modes.
In strict level 0, learning mode, Veriexec will act passively and simply warn
about any anomalies. Combined with verbose level 1, running the system in this
mode can help you fine-tune the signatures file. This is also the only strict
level in which you can load new entries to the kernel.
Strict level 1, or IDS mode, will deny access to files with a fingerprint
mismatch. This mode suits mostly to users who simply want to prevent access to
files which might've been maliciously modified by an attacker.
Strict level 2, IPS mode, takes a step towards trying to protect the integrity
of monitored files. In addition to preventing access to files with a
fingerprint mismatch, it will also deny write access and prevent the removal of
monitored files, and enforce the way monitored files are accessed. (as the
signatures file specifies).
Lockdown mode (strict level 3) can be used in highly critical situations such
as custom made special-purpose machines, or as a last line of defense after an
attacker compromised the system and we want to prevent traces from being
removed, so we can perform post-mortem analysis. It will prevent the creation
of new files, and deny access to files not monitored by Veriexec.
It's recommended to first run Veriexec in strict level 0 and verbose level 1 to
fine-tune your signatures file, ensuring that desired applications run
correctly, and only then raise the strict level (and lower the verbosity
level). You can use /etc/sysctl.conf to auto raise the strict level to the
desired level after a reboot:
kern.veriexec.strict=1
21.5. Öeriexec and layered file systems
Veriexec can be used on NFS file systems on the client side and on layered file
systems such as the union file system. The files residing on these file systems
need only be specified in the /etc/signatures file and that the file systems be
mounted prior to the fingerprints being loaded.
If you are going to use layered file systems then you must ensure that you
include the fingerprint for files you want protected at every layer. If you
fail to do this someone could overwrite a file protected by Veriexec by using a
different layer in a layered file system stack. This limitation may be removed
in later versions of NetBSD.
It's recommended that if you are not going to use layered file systems nor NFS
then these features should be disabled in they kernel configuration. If you
need to use layered file systems then you must follow the instructions in the
previous paragraph and ensure that the files you want protected have
fingerprints at all layers. Also you should raise securelevel to 2 after all
mounts are done:
kern.securelevel=2
To prevent new layers being mounted which could compromise Veriexec's
protection.
21.6. Ëernel configuration
To use Veriexec, aside from creating a signatures file, you should enable
(uncomment) it in your kernel's config file: (e.g. /usr/src/sys/arch/i386/conf/
GENERIC):
pseudo-device veriexec
Then, you need to enable the hashing algorithms you wish to support:
options VERIFIED_EXEC_FP_MD5
options VERIFIED_EXEC_FP_SHA1
options VERIFIED_EXEC_FP_RMD160
options VERIFIED_EXEC_FP_SHA512
options VERIFIED_EXEC_FP_SHA384
options VERIFIED_EXEC_FP_SHA256
Depending on your operating system version and platform, these may already be
enable. Once done, rebuild and reinstall your kernel, see Chapter4, Compiling
the kernel for further instructions.
If you do not have the Veriexec device /dev/veriexec, you can create it
manually by running the following command:
# cd /dev
# sh MAKEDEV veriexec
Chapter2. Âluetooth on NetBSD
Table of Contents
22.1. Introduction
22.2. Supported Hardware
22.3. System Configuration
22.4. Human Interface Devices
22.4.1. Mice
22.4.2. Keyboards
22.5. Personal Area Networking
22.5.1. Personal Area Networking User
22.6. Serial Connections
22.7. Audio
22.7.1. SCO Audio Headsets
22.7.2. SCO Audio Handsfree
22.8. Object Exchange
22.9. Troubleshooting
22.1. Éntroduction
Bluetooth is a digital radio protocol used for short range and low power
communications. NetBSD includes support for the Bluetooth protocol stack, and
some integration of service profiles into the NetBSD device framework.
The lower layers of the Bluetooth protocol stack pertaining to actual radio
links between devices are handled inside the Bluetooth Controller, which
communicates with the Host computer using the "Host Controller Interface" (HCI)
protocol which can be accessed via a raw packet BTPROTO_HCI socket interface.
Most of the Bluetooth protocols or services layer atop the "Link Layer Control
and Adaptation Protocol" (L2CAP), which can be accessed via a BTPROTO_L2CAP
socket interface. This provides sequential packet connections to remote
devices, with up to 64k channels. When an L2CAP channel is opened, the protocol
or service that is required is identified by a "Protocol/Service Multiplexer"
(PSM) value.
Service Discovery in the Bluetooth environment is provided for by the sdp(3)
library functions and the sdpd(8) daemon, which keeps a database of locally
registered services and makes the information available to remote devices
performing queries. The sdpquery(1) tool can be used to query local and remote
service databases.
Security on Bluetooth links can be enabled by encryption and authentication
options to btconfig(8) which apply to all baseband links that a controller
makes, or encryption and authentication can be enabled for individual RFCOMM
and L2CAP links as required. When authentication is requested, a PIN is
presented by each side (generally entered by the operator, some limited input
devices have a fixed PIN). The controller uses this PIN to generate a Link Key
and reports this to the Host which may be asked to produce it to authenticate
subsequent connections. On NetBSD, the bthcid(8) daemon is responsible for
storing link keys and responding to Link Key Requests, and also provides an
interface to allow unprivileged users to specify a PIN with a PIN client, such
as btpin(1).
22.2. Óupported Hardware
Because Bluetooth controllers normally use the standard HCI protocol as
specified in the "Bluetooth 2.0 Core" documentation to communicate with the
host, the NetBSD Bluetooth stack is compatible with most controllers, only
requiring an interface driver:
* bcsp(4) provides a tty(4) line discipline to send and receive BlueCore
Serial Protocol packets over a serial line as described in the "BlueCore
Serial Protocol (BCSP)" specification.
* bt3c(4) provides an interface to the 3Com Bluetooth PC Card, model
3CRWB6096-A.
* btbc(4) provides support for the AnyCom BlueCard (LSE041, LSE039, LSE139)
PCMCIA devices.
* btuart(4) provides a tty(4) line discipline to send and receive Bluetooth
packets over a serial line as described in the "Bluetooth Host Controller
Interface [Transport Layer] specification, Vol 4 part A".
* sbt(4) provides support for Secure Digital IO Bluetooth adapters.
* ubt(4) interfaces to all USB Bluetooth controllers conforming to the "HCI
USB Transport Layer" specification.
If the hardware is supported by the NetBSD Bluetooth stack, autoconfiguration
messages will show up in the dmesg output, for example:
bt3c0 at pcmcia0 function 0: <3COM, 3CRWB60-A, Bluetooth PC Card>
ubt0 at uhub1 port 4 configuration 1 interface 0
ubt0: Cambridge Silicon Radio Bluetooth USB Adapter, rev 2.00/19.58, addr 4
ubt1 at uhub1 port 2 configuration 1 interface 0
ubt1: Broadcom Belkin Bluetooth Device, rev 1.10/0.01, addr 5
When support is not already compiled in, it can be added to the kernel
configuration file for any platform that supports USB and/or PCMCIA (see
Section0.9, "Kernel Tuning"), using the following declarations, as required:
# Bluetooth Controller and Device support
pseudo-device bcsp # BlueCore Serial Protocol
pseudo-device btuart # Bluetooth HCI UART
# Bluetooth PCMCIA Controllers
bt3c* at pcmcia? function ? # 3Com 3CRWB6096-A
btbc* at pcmcia? function ? # AnyCom BlueCard LSE041/039/139
# Bluetooth SDIO Controllers
sbt* at sdmmc?
# Bluetooth USB Controllers
ubt* at uhub? port ?
# Bluetooth Device Hub
bthub* at bcsp?
bthub* at bt3c?
bthub* at btbc?
bthub* at btuart?
bthub* at sbt?
bthub* at ubt?
# Bluetooth HID support
bthidev* at bthub?
# Bluetooth Mouse
btms* at bthidev? reportid ?
wsmouse* at btms? mux 0
# Bluetooth Keyboard
btkbd* at bthidev? reportid ?
wskbd* at btkbd? console ? mux 1
# Bluetooth Audio support
btsco* at bthub?
Some older USB Bluetooth dongles based on the Broadcom BCM2033 chip require
firmware to be loaded before they can function, and these devices will be
attached to ugen(4). Use the "sysutils/bcmfw" package from the NetBSD Package
Collection, to load firmware and enable these.
22.3. Óystem Configuration
To fully enable Bluetooth services on NetBSD, the following line should be
added to the /etc/rc.conf file.
bluetooth=YES
and either reboot, or execute the following command:
# /etc/rc.d/bluetooth start
Configuration of Bluetooth controllers is done with the btconfig(8) program,
and the above argument enables only basic functionality, see the manual page
for other useful options. The extra options for btconfig on a given device, say
utb0, can be set by adding a line for it to the /etc/rc.conf file.
btconfig_ubt0="name MyComputerName"
Important
bthcid(8) must be running in order to make authenticated connections with
remote devices, and authentication may be requested by either device.
22.4. Èuman Interface Devices
Support for "Human Interface Devices" (HIDs), which operate using the USB HID
protocol over a pair of L2CAP channels is provided by the bthidev(4) driver.
Currently, keyboards and mice are catered for, and attach to wscons(4) as
normal.
22.4.1. Íice
Bluetooth Mice can be attached to the system with the btms(4) driver, using
btdevctl(8).
First, you must discover the BDADDR of the device. This may be printed on the
box, but the easiest way is to place the device into discoverable mode and
perform a device inquiry with the appropriate controller:
% btconfig ubt0 inquiry
Device Discovery on ubt0 .... 1 response
1: bdaddr 00:14:51:c1:b9:2d (unknown)
: name "Mighty Mouse"
: class: [0x002580] Peripheral Mouse <Limited Discoverable>
: page scan rep mode 0x01
: page scan period mode 0x02
: page scan mode 0x00
: clock offset 6944
For ease of use, you may want to add the address to the /etc/bluetooth/hosts
file, so that you can refer to the mouse by alias:
# echo "00:14:51:c1:b9:2d mouse" >>/etc/bluetooth/hosts
Now, you can query the mouse, which will likely request authentication before
it accepts connections. The fixed PIN should be listed in the documentation,
though "0000" is often used. Set the PIN first using the btpin(1) program:
% btpin -d ubt0 -a mouse -p 0000
# btdevctl -d ubt0 -a mouse -s HID
local bdaddr: 00:08:1b:8d:ba:6d
remote bdaddr: 00:14:51:c1:b9:2d
link mode: auth
device type: bthidev
control psm: 0x0011
interrupt psm: 0x0013
Collection page=Generic_Desktop usage=Mouse
Input id=2 size=1 count=1 page=Button usage=Button_1 Variable, logical range 0..1
Input id=2 size=1 count=1 page=Button usage=Button_2 Variable, logical range 0..1
Input id=2 size=1 count=1 page=Button usage=Button_3 Variable, logical range 0..1
Input id=2 size=1 count=1 page=Button usage=Button_4 Variable, logical range 0..1
Input id=2 size=4 count=1 page=0x0000 usage=0x0000 Const Variable, logical range 0..1
Collection page=Generic_Desktop usage=Pointer
Input id=2 size=8 count=1 page=Generic_Desktop usage=X Variable Relative, logical range -127..127
Input id=2 size=8 count=1 page=Generic_Desktop usage=Y Variable Relative, logical range -127..127
Input id=2 size=8 count=1 page=Consumer usage=AC_Pan Variable Relative, logical range -127..127
Input id=2 size=8 count=1 page=Generic_Desktop usage=Wheel Variable Relative, logical range -127..127
End collection
Input id=2 size=8 count=1 page=0x00ff usage=0x00c0 Variable, logical range -127..127
Feature id=71 size=8 count=1 page=0x0006 usage=0x0020 Variable NoPref Volatile, logical range 0..100
End collection
This tells you that the mouse has responded to an SDP query, and the device
capabilities are shown. Note that authentication is enabled by default for
Bluetooth mice. You may now attach to the system:
# btdevctl -d ubt0 -a mouse -s HID -A
which should generate some messages on the system console:
bthidev0 at bthub0 remote-bdaddr 00:14:51:c1:b9:2d link-mode auth
btms0 at bthidev1 reportid 2: 4 buttons, W and Z dirs.
wsmouse1 at btms0 mux 0
bthidev1: reportid 71 not configured
bthidev1: connected
and the mouse should work.
The device capabilities are cached by btdevctl(8), and to reattach the mouse at
system startup, place an entry in /etc/bluetooth/btdevctl.conf. The bthidev(4)
driver will attempt to connect once, though mice will usually be sleeping and
may require a tap on the shoulder to awaken, in which case they should initiate
the connection to the host computer.
22.4.2. Ëeyboards
Bluetooth Keyboards can be attached to the system with the btkbd(4) driver,
using btdevctl(8).
First, you must discover the BDADDR of the device. This may be printed on the
box, but the easiest way is to place the device into discoverable mode and
perform a device inquiry with the appropriate controller:
% btconfig ubt0 inquiry
Device Discovery on ubt0 .... 1 response
1: bdaddr 00:0a:95:45:a4:a0 (unknown)
: name "Apple Wireless Keyboard"
: class: [0x002540] Peripheral Keyboard <Limited Discoverable>
: page scan rep mode 0x01
: page scan period mode 0x00
: page scan mode 0x00
: clock offset 18604
For ease of use, you may want to add the address to the /etc/bluetooth/hosts
file, so that you can refer to the keyboard by alias:
# echo "00:0a:95:45:a4:a0 keyboard" >>/etc/bluetooth/hosts
Now, you can query the keyboard, which will likely request authentication
before it accepts connections. The PIN will need to be entered on the keyboard,
and we can generate a random PIN, using the btpin(1) program.
% btpin -d ubt0 -a keyboard -r -l 8
PIN: 18799632
# btdevctl -d ubt0 -a keyboard -s HID
< ENTER PIN ON BLUETOOTH KEYBOARD NOW >
local bdaddr: 00:08:1b:8d:ba:6d
remote bdaddr: 00:0a:95:45:a4:a0
link mode: encrypt
device type: bthidev
control psm: 0x0011
interrupt psm: 0x0013
Collection page=Generic_Desktop usage=Keyboard
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_LeftControl Variable, logical range 0..1
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_LeftShift Variable, logical range 0..1
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_LeftAlt Variable, logical range 0..1
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_Left_GUI Variable, logical range 0..1
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_RightControl Variable, logical range 0..1
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_RightShift Variable, logical range 0..1
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_RightAlt Variable, logical range 0..1
Input id=1 size=1 count=1 page=Keyboard usage=Keyboard_Right_GUI Variable, logical range 0..1
Input id=1 size=8 count=1 page=0x0000 usage=0x0000 Const, logical range 0..1
Output id=1 size=1 count=1 page=LEDs usage=Num_Lock Variable, logical range 0..1
Output id=1 size=1 count=1 page=LEDs usage=Caps_Lock Variable, logical range 0..1
Output id=1 size=1 count=1 page=LEDs usage=Scroll_Lock Variable, logical range 0..1
Output id=1 size=1 count=1 page=LEDs usage=Compose Variable, logical range 0..1
Output id=1 size=1 count=1 page=LEDs usage=Kana Variable, logical range 0..1
Output id=1 size=3 count=1 page=0x0000 usage=0x0000 Const, logical range 0..1
Input id=1 size=8 count=6 page=Keyboard usage=No_Event, logical range 0..255
Input id=1 size=1 count=1 page=Consumer usage=Eject Variable Relative, logical range 0..1
Input id=1 size=1 count=1 page=Consumer usage=Mute Variable Relative, logical range 0..1
Input id=1 size=1 count=1 page=Consumer usage=Volume_Up Variable, logical range 0..1
Input id=1 size=1 count=1 page=Consumer usage=Volume_Down Variable, logical range 0..1
Input id=1 size=1 count=4 page=0x0000 usage=0x0000 Const, logical range 0..1
End collection
This tells you that the keyboard has responded to an SDP query, and the device
capabilities are shown. Note that encryption is enabled by default, since
encrypted connection support is mandatory for Bluetooth keyboards. You may now
attach to the system:
# btdevctl -d ubt0 -a keyboard -s HID -A
which should generate some messages on the system console:
bthidev1 at bthub0 remote-bdaddr 00:0a:95:45:a4:a0 link-mode encrypt
btkbd0 at bthidev0 reportid 1
wskbd1 at btkbd0 mux 1
wskbd1: connecting to wsdisplay0
bthidev1: connected
and the keyboard should work.
The device capabilities are cached by btdevctl(8), and to reattach the keyboard
at system startup, place an entry in /etc/bluetooth/btdevctl.conf. The bthidev
(4) driver will attempt to connect once when attached, but if the keyboard is
not available at that time, you may find that pressing a key will cause it to
wake up and initiate a connection to the last paired host.
22.5. Ðersonal Area Networking
Personal Area Networking services over Bluetooth are provided by the btpand(8)
daemon which can assume all roles from the PAN profile and connects remote
devices to the system through a tap(4) virtual Ethernet interface.
22.5.1. Ðersonal Area Networking User
The "Personal Area Networking User" role is the client that accesses Network
services on another device. For instance, in order to connect to the Internet
via a smart phone with the NAP profile, make sure that the phone is
discoverable, then:
% btconfig ubt0 inquiry
Device Discovery from device: ubt0 .... 1 response
1: bdaddr 00:17:83:30:bd:5e (unknown)
: name "HTC Touch"
: class: [0x5a020c] Smart Phone <Networking> <Capturing> <Object Transfer>
<Telephony>
: page scan rep mode 0x01
: clock offset 9769
: rssi -42
# echo "00:17:83:30:bd:5e phone" >>/etc/bluetooth/hosts
You will see that the phone should have the <Networking> flag set in the Class
of Device. Checking for the NAP service:
% sdpquery -a phone search NAP
ServiceRecordHandle: 0x00010000
ServiceClassIDList:
Network Access Point
ProtocolDescriptorList:
L2CAP (PSM 0x000f)
BNEP (v1.0; IPv4, ARP, IPv6)
LanguageBaseAttributeIDList:
en.UTF-8 base 0x0100
BluetoothProfileDescriptorList:
Network Access Point, v1.0
ServiceName: "Network Access Point"
ServiceDescription: "Bluetooth NAP Service"
SecurityDescription: None
NetAccessType: 100Mb Ethernet
MaxNetAccessRate: 100000
reveals that the NAP service is available and that it provides IPv4, ARP and
IPv6 protocols.
Most likely, the phone will request authentication before it allows connections
to the NAP service, so before you make the first connection you may need to
provide a PIN, which can be randomly generated. Then start btpand(8):
% btpin -d ubt0 -a phone -r -l 6
PIN: 862048
# btpand -d ubt0 -a phone -s NAP
< ENTER PIN ON PHONE NOW >
Searching for NAP service at 00:17:83:30:bd:5e
Found PSM 15 for service NAP
Opening connection to service 0x1116 at 00:17:83:30:bd:5e
Using interface tap0 with addr 00:10:60:e1:50:3d
Finally, you will need to configure the tap(4) interface, but the phone should
have a DHCP server so dhcpcd(8) will do that for you.
# dhcpcd tap0
Now you can surf the World Wide Web, but watch your data usage unless you have
a comprehensive data plan.
22.6. Óerial Connections
Serial connections over Bluetooth are provided for by the RFCOMM protocol,
which provides up to 30 channels multiplexed over a single L2CAP channel. This
streamed data protocol can be accessed using the BTPROTO_RFCOMM socket
interface, or via the rfcomm_sppd(1) program.
For instance, you can make a serial connection to the "Dial Up Networking"
(DUN) service of a mobile phone in order to connect to the Internet with PPP.
First you should discover the BDADDR of the phone, and add this to your /etc/
bluetooth/hosts for ease of use. Place the phone into Discoverable mode, and
perform an inquiry from the appropriate controller:
% btconfig ubt0 inquiry
Device Discovery from device: ubt0 ..... 1 response
1: bdaddr 00:16:bc:00:e8:48 (unknown)
: name "Nokia 6103"
: class: [0x520204] Cellular Phone <Networking> <Object Transfer> <Telephony>
: page scan rep mode 0x01
: page scan period mode 0x02
: page scan mode 0x00
: clock offset 30269
# echo "00:16:bc:00:e8:48 phone" >>/etc/bluetooth/hosts
Now, you can query the phone to confirm that it supports the DUN profile:
% sdpquery -d ubt0 -a phone search DUN
ServiceRecordHandle: 0x00010003
ServiceClassIDList:
Dialup Networking
Generic Networking
ProtocolDescriptorList:
L2CAP
RFCOMM (channel 1)
BrowseGroupList:
Public Browse Root
LanguageBaseAttributeIDList:
en.UTF-8 base 0x0100
BluetoothProfileDescriptorList:
Dialup Networking, v1.0
ServiceName: "Dial-up networking"
Most likely, the phone will request authentication before it allows connections
to the DUN service, so before you make the first connection you may need to
provide a PIN, which can be randomly generated. You can use rfcomm_sppd in
stdio mode to check that the connection is working ok, press ^C to disconnect
and return to the shell, for example:
% btpin -d ubt0 -a phone -r -l 6
PIN: 904046
% rfcomm_sppd -d ubt0 -a phone -s DUN
< ENTER PIN ON PHONE NOW >
rfcomm_sppd[24635]: Starting on stdio...
at
OK
ati
Nokia
OK
ati3
Nokia 6103
OK
at&v
ACTIVE PROFILE:
E1 Q0 V1 X5 &C1 &D2 &S0 &Y0
+CMEE=0 +CSTA=129 +CBST=0,0,1 +CRLP=61,61,48,6 +CR=0 +CRC=0 +CLIP=0,2
+CLIR=0,2 +CSNS=0 +CVHU=1 +DS=0,0,2048,32 +DR=0 +ILRR=0
+CHSN=0,0,0,0 +CHSR=0 +CPBS="SM"
S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S07:060 S08:002
S10:100 S12:050 S25:000
OK
^C
rfcomm_sppd[24635]: Completed on stdio
To have pppd(8) connect to the DUN service of your phone automatically when
making outbound connections, add the following line to the /etc/ppp/options
file in place of the normal tty declaration:
pty "rfcomm_sppd -d ubt0 -a phone -s DUN -m encrypt"
22.7. Áudio
Isochronous (SCO) Audio connections may be created on a baseband radio link
using either the BTPROTO_SCO socket interface, or the btsco(4) audio device
driver. While the specification says that up to three such links can be made
between devices, the current Bluetooth stack can only handle one with any
dignity.
Important
When using SCO Audio with USB Bluetooth controllers, you will need to enable
isochronous data, and calculate the MTU that the device will use, see ubt(4)
and btconfig(8).
Note
SCO Audio does not work properly with the bt3c(4) driver, use a USB controller
for best results.
22.7.1. ÓCO Audio Headsets
Audio connections to Bluetooth Headsets are possible using the btsco(4) audio
driver, and the bthset(1) program. First, you need to discover the BDADDR of
the headset, and will probably wish to make an alias in your /etc/bluetooth/
hosts file for ease of use. Place the headset into discoverable mode and
perform an inquiry with the appropriate controller:
% btconfig ubt0 inquiry
Device Discovery from device: ubt0 ..... 1 response
1: bdaddr 00:07:a4:23:10:83 (unknown)
: name "JABRA 250"
: class: [0x200404] Wearable Headset <Audio>
: page scan rep mode 0x01
: page scan period mode 0x00
: page scan mode 0x00
: clock offset 147
# echo "00:07:a4:23:10:83 headset" >>/etc/bluetooth/hosts
You will need to pair with the headset the first time you connect, the fixed
PIN should be listed in the manual (often, "0000" is used). btdevctl(8) will
query the device and attach the btsco(4) audio driver.
% btpin -d ubt0 -a headset -p 0000
# btdevctl -d ubt0 -a headset -s HSET -A
local bdaddr: 00:08:1b:8d:ba:6d
remote bdaddr: 00:07:a4:23:10:83
link mode: none
device type: btsco
mode: connect
channel: 1
which should generate some messages on the system console:
btsco0 at bthub0 remote-bdaddr 00:07:a4:23:10:83 channel 1
audio1 at btsco0: full duplex
In order to use the audio device, you will need to open a control connection
with bthset(1) which conveys volume information to the mixer device.
% bthset -m /dev/mixer1 -v
Headset Info:
mixer: /dev/mixer1
laddr: 00:08:1b:8d:ba:6d
raddr: 00:07:a4:23:10:83
channel: 1
vgs.dev: 0, vgm.dev: 1
and you should now be able to transfer 8khz samples to and from /dev/audio1
using any program that supports audio, such as audioplay(1) or audiorecord(1).
Adjusting the mixer values should work when playing though you may find that
when opening a connection, the headset will reset the volume to the last known
settings.
% audiorecord -d /dev/audio1 voice.au
< TALK NONSENSE NOW >
^C
% audioplay -d /dev/audio voice.au
< THATS REALLY WHAT YOU SOUND LIKE >
% audioplay -d /dev/audio1 voice.au
< IN THE HEADSET >
The device capabilities are cached by btdevctl(8), and to reattach the btsco(4)
driver at system startup, add an entry to /etc/bluetooth/btdevctl.conf.
22.7.2. ÓCO Audio Handsfree
Audio connections to Bluetooth mobile phones using the Handsfree profile are
possible with the "comms/bthfp" program from the NetBSD Package Collection.
First, you need to discover the BDADDR of the phone, and will probably wish to
make an alias in your /etc/bluetooth/hosts file for ease of use. Place the
phone into discoverable mode and perform an inquiry with the appropriate
controller:
% btconfig ubt0 inquiry
Device Discovery from device: ubt0 ..... 1 response
1: bdaddr 00:16:bc:00:e8:48 (unknown)
: name "Nokia 6103"
: class: [0x520204] Cellular Phone <Networking;gt; <Object Transfer;gt; <Telephony;gt;
: page scan rep mode 0x01
: page scan period mode 0x02
: page scan mode 0x00
: clock offset 10131
# echo "00:16:bc:00:e8:48 phone" >>/etc/bluetooth/hosts
Now, you should be able to query the phone to confirm that it supports the
Handsfree profile:
% sdpquery -d ubt0 -a phone search HF
ServiceRecordHandle: 0x00010006
ServiceClassIDList:
Handsfree Audio Gateway
Generic Audio
ProtocolDescriptorList:
L2CAP
RFCOMM (channel 13)
BrowseGroupList:
Public Browse Root
LanguageBaseAttributeIDList:
en.UTF-8 base 0x0100
BluetoothProfileDescriptorList:
Handsfree, v1.5
ServiceName: "Voice Gateway"
Network: Ability to reject a call
SupportedFeatures:
3 Way Calling
Echo Cancellation/Noise Reduction
Voice Recognition
In-band Ring Tone
and you will be able to use the bthfp program to access the Handsfree profile.
The first time you connect, you may need to use a PIN to pair with the phone,
which can be generated randomly by btpin(1):
% btpin -d ubt0 -a phone -r -l 6
PIN: 349163
% bthfp -d ubt0 -a phone -v
< ENTER PIN ON PHONE NOW >
Handsfree channel: 13
Press ? for commands
Connecting.. ok
< AT+BRSF=20
> +BRSF: 47
Features: [0x002f] <3 way calling> <EC/NR> <Voice Recognition> <In-band ringtone> <reject ability>
> OK
< AT+CIND=?
> +CIND: ("call",(0,1)),("service",(0,1)),("call_setup",(0-3)),("callsetup",(0-3))
> OK
< AT+CIND?
> +CIND: 0,1,0,0
> OK
< AT+CMER=3,0,0,1
> OK
< AT+CLIP=1
> OK
Service Level established
When the phone rings, just press a to answer, and audio should be routed
through the /dev/audio device. Note that you will need a microphone connected
in order to speak to the remote party.
22.8. Ïbject Exchange
NetBSD does not currently have any native OBEX capability, see the "comms/
obexapp" or "comms/obexftp" packages from the NetBSD Package Collection.
22.9. Ôroubleshooting
When nothing seems to be happening, it may be useful to try the hcidump program
from the "sysutils/netbt-hcidump" package in the NetBSD Package Collection.
This has the capability to dump packets entering and leaving Bluetooth
controllers on NetBSD, which is greatly helpful in pinpointing problems.
Chapter3. Ìinux emulation
Table of Contents
23.1. Emulation setup
23.1.1. Configuring the kernel
23.1.2. Installing the Linux libraries
23.1.3. Running Linux programs
23.2. Directory structure
23.3. Using Linux browser plugins
23.4. Further reading
The NetBSD port for amd64, i386, alpha, mac68k, macppc, and many others can
execute a great number of native Linux programs, using the Linux emulation
layer. Generally, when you think about emulation you imagine something slow and
inefficient because, often, emulations must reproduce hardware instructions and
even architectures (usually from old machines) in software. In the case of the
Linux emulation this is radically different: it is only a thin software layer,
mostly for system calls which are already very similar between the two systems.
The application code itself is processed at the full speed of your CPU, so you
don't get a degraded performance with the Linux emulation and the feeling is
exactly the same as for native NetBSD applications.
23.1. Åmulation setup
The installation of the Linux emulation is described in the compat_linux(8) man
page; using the package system only two steps are needed.
23.1.1. Ãonfiguring the kernel
If you use a GENERIC kernel you don't need to do anything because Linux
compatibility is already enabled.
If you use a customized kernel, check that the following options are enabled:
option COMPAT_LINUX
option EXEC_ELF32
or the following options if you are going to use 64-bit ELF binaries:
option COMPAT_LINUX
option EXEC_ELF64
when you have compiled a kernel with the previous options you can start
installing the necessary software.
23.1.2. Énstalling the Linux libraries
Usually, applications are linked against shared libraries, and for Linux
applications, Linux shared libraries are needed. You can get the shared
libraries from any Linux distribution, provided it's not too old, but the
suggested method is to use the package system to install the provided libraries
from openSUSE.
All Linux binaries exist entirely within the separate root directories inside /
emul/linux and /emul/linux32. The kernel will always search these paths first
when looking for shared objects required by Linux programs.
A number of useful Linux shared object binaries is provided by pkgsrc, for
running both 64-bit and 32-bit applications. The absolute minimum required to
run dynamically linked Linux applications are are provided by the suse131_base
and suse131_32_base packages (or, if using binary packages suse_base-13 and
suse32_base-13). Many other libraries are also provided as separate packages.
Some packages in pkgsrc are provided as Linux binaries and will also install
all the required SUSE dependencies when installed. However, this is uncommon.
One such package is adoptopenjdk11-bin.
It is possible to examine which libraries are required by a Linux program with
readelf(1):
$ readelf -d ./runner
Dynamic section at offset 0x3a2e94 contains 40 entries:
Tag Type Name/Value
0x00000001 (NEEDED) Shared library: [libstdc++.so.6]
0x00000001 (NEEDED) Shared library: [libz.so.1]
0x00000001 (NEEDED) Shared library: [libXxf86vm.so.1]
0x00000001 (NEEDED) Shared library: [libGL.so.1]
0x00000001 (NEEDED) Shared library: [libopenal.so.1]
0x00000001 (NEEDED) Shared library: [libm.so.6]
0x00000001 (NEEDED) Shared library: [librt.so.1]
0x00000001 (NEEDED) Shared library: [libpthread.so.0]
0x00000001 (NEEDED) Shared library: [libdl.so.2]
0x00000001 (NEEDED) Shared library: [libcrypto.so.1.0.0]
0x00000001 (NEEDED) Shared library: [libXext.so.6]
0x00000001 (NEEDED) Shared library: [libX11.so.6]
0x00000001 (NEEDED) Shared library: [libXrandr.so.2]
0x00000001 (NEEDED) Shared library: [libGLU.so.1]
0x00000001 (NEEDED) Shared library: [libssl.so.1.0.0]
0x00000001 (NEEDED) Shared library: [libgcc_s.so.1]
0x00000001 (NEEDED) Shared library: [libc.so.6]
For example, an application which requires libcrypto.so.1.0.0, libXext.so.6,
and libGL.so.1 will require openssl, x11, and glx, in addition to the base SUSE
package.
23.1.3. Òunning Linux programs
Once the correct libraries are installed, no special steps are required to run
a Linux program - simply type the command (if you acquired it as a non-pkgsrc
download, include the full path on the filesystem). The kernel will detect it
is a Linux executable and run it in the correct translation mode.
23.2. Äirectory structure
If we examine the outcome of the installation of the Linux libraries and
programs we find that /emul/linux is a symbolic link pointing to /usr/pkg/emul/
linux, where the following directories have been created:
bin/
dev/
etc/
lib/
lib64/
proc/
sbin/
usr/
var/
Note
Please always refer to /emul/linux and not to /usr/pkg/emul/linux. The latter
is an implementation detail and may change in the future.
How much space is required for the Linux emulation software? On one system we
got the following figure:
# cd /usr/pkg/emul
# du -k /emul/linux/
...
399658 /emul/linux/
23.3. Õsing Linux browser plugins
Linux plugins for Mozilla-based browsers can be used on native NetBSD Firefox
builds through nspluginwrapper, a wrapper that translates between the native
browser and a foreign plugin. At the moment, nspluginwrapper only works
reliably on Mozilla-based browsers that link against GTK2+ (GTK1+ is not
supported). nspluginwrapper can be installed through pkgsrc:
# cd /usr/pkgsrc/www/nspluginwrapper
# make install
Plugins can then be installed in two steps: first, the plugin has to be
installed on the system (e.g. through pkgsrc). After that the plugin should be
registered with the nspluginwrapper by the users who want to use that plugin.
In this short example we will have a look at installing the Macromedia Flash
plugin. We can fullfill the first step by installing the Flash plugin through
pkgsrc:
# cd /usr/pkgsrc/multimedia/ns-flash
# make install
After that an unprivileged user can register the Flash plugin:
$ nspluginwrapper -i /usr/pkg/lib/netscape/plugins/libflashplayer.so
The plugin should then be registered correctly. You can check this by using the
-l option of nspluginwrapper (nspluginwrapper -l). If the plugin is listed, you
can restart Firefox, and verify that the plugin was installed by entering
about:plugins in the location bar.
23.4. Æurther reading
The following articles may be of interest for further understanding Linux (and
other) emulation:
Bibliography
[chap-linux-further-implementing-linux-emul-on-netbsd] Implementing Linux
emulation on NetBSD . Peter Seebach. May 2004.
Chapter4. Íiscellaneous operations
Table of Contents
24.1. Installing the boot manager
24.2. Deleting the disklabel
24.3. Speaker
24.4. Forgot root password?
24.5. Password file is busy?
24.6. Adding a new hard disk
24.7. How to rebuild the devices in /dev
This chapter collects various topics, in sparse order
24.1. Énstalling the boot manager
Sysinst, the NetBSD installation program usually installs the NetBSD boot
manager on the hard disk. The boot manager can also be installed or
reconfigured at a later time, if needed, with the fdisk command. For example:
# fdisk -B wd0
If NetBSD doesn't boot from the hard disk, you can boot it from the
installation floppy and start the kernel on the hard disk. Insert the
installation disk and, at the boot prompt, give the following command:
> boot wd0a:netbsd
This boots the kernel on the hard disk (use the correct device, for example
sd0a for a SCSI disk).
Note
Sometimes fdisk -B doesn't give the expected result (at least it happened to
me), probably if you install/remove other operating systems. In this case, try
running fdisk -i and then run again fdisk from NetBSD.
24.2. Äeleting the disklabel
Though this is not an operation that you need to perform frequently, it can be
useful to know how to do it in case of need. Please be sure to know exactly
what you are doing before performing this kind of operation. For example:
# dd if=/dev/zero of=/dev/rwd0c bs=8k count=1
The previous command deletes the disklabel (not the MBR partition table). To
completely delete the disk, the whole device rwd0d must be used. For example:
# dd if=/dev/zero of=/dev/rwd0d bs=8k
The commands above will only work as expected on the i386 and amd64 ports of
NetBSD. On other ports, the whole device will end in c, not d (e.g. rwd0c).
24.3. Ópeaker
To output a sound from the speaker (for example at the end of a long script)
the spkr driver can be used in the kernel config, which is mapped on /dev/
speaker. For example:
echo 'BPBPBPBPBP' > /dev/speaker
Note
The spkr device is not enabled in the generic kernel; a customized kernel is
needed.
24.4. Æorgot root password?
If you forget root's password, not all is lost and you can still recover the
system with the following steps: boot single user, mount / and change root's
password. In detail:
1. Boot single user: when the boot prompt appears and the five seconds
countdown starts, give the following command:
> boot -s
2. At the following prompt
Enter pathname of shell or RETURN for sh:
press Enter.
3. Write the following commands:
# fsck -y /
# mount -u /
# fsck -y /usr
# mount /usr
4. Change root's password:
# passwd root
Changing local password for root.
New password: (not echoed)
Retype new password: (not echoed)
#
5. Exit the shell to go to multiuser mode.
# exit
If you get the error "Password file is busy", please see the section below.
24.5. Ðassword file is busy?
If you try to modify a password and you get the mysterious message "Password
file is busy", it probably means that the file /etc/ptmp has not been deleted
from the system. This file is a temporary copy of the /etc/master.passwd file;
check that you are not losing important information and then delete it:
# rm /etc/ptmp
Note
If the file /etc/ptmp exists you can also receive a warning message at system
startup. For example:
root: password file may be incorrect - /etc/ptmp exists
24.6. Ádding a new hard disk
This section describes how to add a new hard disk to an already working NetBSD
system. In the following example a new SCSI controller and a new hard disk,
connected to the controller, will be added. If you don't need to add a new
controller, skip the relevant part and go to the hard disk configuration. The
installation of an IDE hard disk is identical; only the device name will be
different (wd# instead of sd#).
As always, before buying new hardware, consult the hardware compatibility list
of NetBSD and make sure that the new device is supported by the system.
When the SCSI controller has been physically installed in the system and the
new hard disk has been connected, it's time to restart the computer and check
that the device is correctly detected, using the dmesg command. This is the
sample output for an NCR-875 controller:
ncr0 at pci0 dev 15 function 0: ncr 53c875 fast20 wide scsi
ncr0: interrupting at irq 10
ncr0: minsync=12, maxsync=137, maxoffs=16, 128 dwords burst, large dma fifo
ncr0: single-ended, open drain IRQ driver, using on-chip SRAM
ncr0: restart (scsi reset).
scsibus0 at ncr0: 16 targets, 8 luns per target
sd0(ncr0:2:0): 20.0 MB/s (50 ns, offset 15)
sd0: 2063MB, 8188 cyl, 3 head, 172 sec, 512 bytes/sect x 4226725 sectors
If the device doesn't appear in the output, check that it is supported by the
kernel that you are using; if necessary, compile a customized kernel (see
Chapter4, Compiling the kernel).
Now the partitions can be created using the fdisk command. First, check the
current status of the disk:
# fdisk sd0
NetBSD disklabel disk geometry:
cylinders: 8188 heads: 3 sectors/track: 172 (516 sectors/cylinder)
BIOS disk geometry:
cylinders: 524 heads: 128 sectors/track: 63 (8064 sectors/cylinder)
Partition table:
0: sysid 6 (Primary 'big' DOS, 16-bit FAT (> 32MB))
start 63, size 4225473 (2063 MB), flag 0x0
beg: cylinder 0, head 1, sector 1
end: cylinder 523, head 127, sector 63
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
In this example the hard disk already contains a DOS partition, which will be
deleted and replaced with a native NetBSD partition. The command fdisk -u sd0
allows to modify interactively the partitions. The modified data will be
written on the disk only before exiting and fdisk will request a confirmation
before writing, so you can work relaxedly.
Disk geometries
The geometry of the disk reported by fdisk can appear confusing. Dmesg reports
4226725 sectors with 8188/3/172 for C/H/S, but 8188*3*172 gives 4225008 and not
4226725. What happens is that most modern disks don't have a fixed geometry and
the number of sectors per track changes depending on the cylinder: the only
interesting parameter is the number of sectors. The disk reports the C/H/S
values but it's a fictitious geometry: the value 172 is the result of the total
number of sectors (4226725) divided by 8188 and then by 3.
To make things more confusing, the BIOS uses yet another "fake" geometry (C/H/S
524/128/63) which gives a total of 4225536, a value which is a better
approximation to the real one than 425008. To partition the disk we will use
the BIOS geometry, to maintain compatibility with other operating systems,
although we will lose some sectors (4226725 - 4225536 = 1189 sectors = 594 KB).
To create the BIOS partitions the command fdisk -u must be used; the result is
the following:
Partition table:
0: sysid 169 (NetBSD)
start 63, size 4225473 (2063 MB), flag 0x0
beg: cylinder 0, head 1, sector 1
end: cylinder 523, head 127, sector 63
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Now it's time to create the disklabel for the NetBSD partition. The correct
steps to do this are:
# disklabel sd0 > tempfile
# vi tempfile
# disklabel -R -r sd0 tempfile
If you try to create the disklabel directly with
# disklabel -e sd0
you get the following message
disklabel: ioctl DIOCWDINFO: No disk label on disk;
use "disklabel -I" to install initial label
because the disklabel does not yet exist on the disk.
Now we create some disklabel partitions, editing the tempfile as already
explained. The result is:
# size offset fstype [fsize bsize cpg]
a: 2048004 63 4.2BSD 1024 8192 16 # (Cyl. 0*- 3969*)
c: 4226662 63 unused 0 0 # (Cyl. 0*- 8191*)
d: 4226725 0 unused 0 0 # (Cyl. 0 - 8191*)
e: 2178658 2048067 4.2BSD 1024 8192 16 # (Cyl. 3969*- 8191*)
Note
When the disklabel has been created it is possible to optimize it studying the
output of the command newfs -N /dev/rsd0a, which warns about the existence of
unallocated sectors at the end of a disklabel partition. The values reported by
newfs can be used to adjust the sizes of the partitions with an iterative
process.
The final operation is the creation of the file systems for the newly defined
partitions (a and e).
# newfs /dev/rsd0a
# newfs /dev/rsd0e
The disk is now ready for usage, and the two partitions can be mounted. For
example:
# mount /dev/sd0a /mnt
If this succeeds, you may want to put an entry for the partition into /etc/
fstab.
24.7. Èow to rebuild the devices in /dev
First shutdown to single user, partitions still mounted "rw" (read-write); You
can do that by just typing shutdown now while you are in multi user mode, or
reboot with the -s option and make / and /dev read-writable by doing.
# mount -u /
# mount -u /dev
Then:
# mkdir /newdev
# cd /newdev
# cp /dev/MAKEDEV* .
# sh ./MAKEDEV all
# cd /
# mv dev olddev
# mv newdev dev
# rm -r olddev
Or if you fetched all the sources in /usr/src:
# mkdir /newdev
# cd /newdev
# cp /usr/src/etc/MAKEDEV.local .
# ( cd /usr/src/etc ; make MAKEDEV )
# cp /usr/src/etc/obj*/MAKEDEV .
# sh ./MAKEDEV all
# cd /
# mv dev olddev; mv newdev dev
# rm -r olddev
You can determine $arch by
# uname -m
or
# sysctl hw.machine_arch
Part ÉV. Îetworking and related issues
Table of Contents
25. Introduction to TCP/IP Networking
25.1. Audience
25.2. Supported Networking Protocols
25.3. Supported Media
25.3.1. Ethernet
25.3.2. IEEE 802.11 (Wi-Fi)
25.3.3. Serial Line
25.4. TCP/IP Address Format
25.5. Subnetting and Routing
25.6. Name Service Concepts
25.6.1. /etc/hosts
25.6.2. Domain Name Service (DNS)
25.6.3. Network Information Service (NIS/YP)
25.6.4. Other
25.7. IPv6
25.7.1. What good is IPv6?
25.7.2. Changes to IPv4
26. Setting up TCP/IP on NetBSD in practice
26.1. Overview of the network configuration files
26.2. Connecting to common LAN setups
26.2.1. Connecting using IEEE 802.11 (Wi-Fi)
26.3. Manually creating a small LAN
26.4. Connecting to a home/office ISP with PPPoE
26.4.1. Configuring a VLAN
26.4.2. Setting up MSS clamping
26.4.3. Obtaining IPv6 addresses via Prefix Delegation
26.5. Setting up an Internet gateway with NPF
26.6. Setting up a network bridge device
26.6.1. Bridge example
26.7. Ensuring interfaces are initialized in the correct order
26.8. Some useful commands
27. The Internet Super Server inetd
27.1. Overview
27.2. What is inetd?
27.3. Configuring inetd - /etc/inetd.conf
27.4. Services - /etc/services
27.5. Protocols - /etc/protocols
27.6. Remote Procedure Calls (RPC) - /etc/rpc
27.7. Allowing and denying hosts - /etc/hosts.{allow,deny}
27.8. Adding a Service
27.9. When to use or not to use inetd
27.10. Other Resources
28. The Domain Name System
28.1. DNS Background and Concepts
28.1.1. Naming Services
28.1.2. The DNS namespace
28.1.3. Resource Records
28.1.4. Delegation
28.1.5. Delegation to multiple servers
28.1.6. Secondaries, Caching, and the SOA record
28.1.7. Name Resolution
28.1.8. Reverse Resolution
28.2. The DNS Files
28.2.1. /etc/named.conf
28.2.2. /etc/namedb/localhost
28.2.3. /etc/namedb/zone.127.0.0
28.2.4. /etc/namedb/diverge.org
28.2.5. /etc/namedb/1.168.192
28.2.6. /etc/namedb/root.cache
28.3. Using DNS
28.4. Setting up a caching only name server
28.4.1. Testing the server
29. Mail and news
29.1. postfix
29.1.1. Configuration of generic mapping
29.1.2. Testing the configuration
29.1.3. Using an alternative MTA
29.2. fetchmail
29.3. Reading and writing mail with mutt
29.4. Strategy for receiving mail
29.5. Strategy for sending mail
29.6. Advanced mail tools
29.7. News with tin
30. Introduction to the Common Address Redundancy Protocol (CARP)
30.1. CARP Operation
30.2. Configuring CARP
30.3. Enabling CARP Support
30.4. CARP Example
30.5. Advanced CARP configuration
30.6. Forcing Failover of the Master
31. Network services
31.1. The Network File System (NFS)
31.1.1. NFS setup example
31.1.2. Setting up NFS automounting for /net with amd(8)
31.2. The Network Time Protocol (NTP)
Chapter5. Éntroduction to TCP/IP Networking
Table of Contents
25.1. Audience
25.2. Supported Networking Protocols
25.3. Supported Media
25.3.1. Ethernet
25.3.2. IEEE 802.11 (Wi-Fi)
25.3.3. Serial Line
25.4. TCP/IP Address Format
25.5. Subnetting and Routing
25.6. Name Service Concepts
25.6.1. /etc/hosts
25.6.2. Domain Name Service (DNS)
25.6.3. Network Information Service (NIS/YP)
25.6.4. Other
25.7. IPv6
25.7.1. What good is IPv6?
25.7.2. Changes to IPv4
25.1. Áudience
This section explains various aspects of networking. It is intended to help
people with little knowledge about networks to get started. It is divided into
three big parts. We start by giving a general overview of how networking works
and introduce the basic concepts. Then we go into details for setting up
various types of networking in the second parts, and the third part of the
networking section covers a number of "advanced" topics that go beyond the
basic operation as introduced in the first two sections.
The reader is assumed to know about basic system administration tasks: how to
become root, edit files, change permissions, stop processes, etc. See the other
chapters of this NetBSD guide and, e.g., [AeleenFrisch] for further information
on this topic. Besides that, you should know how to handle the utilities we're
going to set up here, i.e., you should know how to use telnet, FTP, ... I will
not explain the basic features of those utilities, please refer to the
appropriate manual pages, the references listed or, of course, the other parts
of this document instead.
This introduction to TCP/IP networking was written with the intention in mind
to give starters a basic knowledge. If you really want to know what it's all
about, read [CraigHunt]. This book does not only cover the basics, but goes on
and explains all the concepts, services and how to set them up in detail. It's
great, I love it! :-)
25.2. Óupported Networking Protocols
There are several protocol suites supported by NetBSD, most of which were
inherited from NetBSD's predecessor, 4.4BSD, and subsequently enhanced and
improved. The first and most important one today is DARPA's Transmission
Control Protocol/Internet Protocol (TCP/IP). Other protocol suites available in
NetBSD include the Stream Control Transmission Protocol (SCTP), and Apple's
AppleTalk protocol suite. They are only used in some special applications.
Today, TCP/IP is the most widespread protocol of the ones mentioned above. It
is implemented on almost every hardware and operating system, and it is also
the most-used protocol in heterogenous environments. So, if you just want to
connect your computer running NetBSD to some other machine at home or you want
to integrate it into your company's or university's network, TCP/IP is the
right choice.
25.3. Óupported Media
The TCP/IP protocol stack behaves the same regardless of the underlying media
used, and NetBSD supports a wide range of these, among them are Ethernet (10/
100Mb/1/10/40/100Gb), USB, serial line and FireWire (IEEE 1394).
25.3.1. Åthernet
Ethernet is the medium commonly used to build local area networks (LANs) of
interconnected machines within a limited area such as an office, company or
university campus. Ethernet is based on a bus structure to which many machines
can connect to, and communication always happens between two nodes at a time.
When two or more nodes want to talk at the same time, both will restart
communication after some timeout. The technical term for this is CSMA/CD
(Carrier Sense w/ Multiple Access and Collision Detection).
Initially, Ethernet hardware consisted of a thick (yellow) cable that machines
tapped into using special connectors that poked through the cable's outer
shielding. The successor of this was called 10base5, which used BNC-type
connectors for tapping in special T-connectors and terminators on both ends of
the bus. Today, ethernet is mostly used with twisted pair lines which are used
in a collapsed bus system that are contained in switches or hubs. The twisted
pair lines give this type of media its name - 10baseT for 10 Mbit/s networks,
and 100baseT for 100 MBit/s ones. In switched environments there's also the
distinction if communication between the node and the switch can happen in
half- or in full duplex mode.
25.3.2. ÉEEE 802.11 (Wi-Fi)
IEEE 802.11 (commonly known as Wi-Fi) is the primary means by which mobile
devices are connected over a Local Area Network.
IEEE 802.11 primarily operates over two radio bands, 2.4 GHz (modes b, g, and
n), and 5 GHz (modes a, and ac). The 2.4 GHz band is typically more congested,
but loses less performance through walls and other barriers.
The main protocol used for securing Wi-Fi connections is WPA (Wi-Fi Protected
Access). In a typical configuration, this encrypts the connection between the
access point and its clients with a password.
25.3.3. Óerial Line
The disadvantage of a serial connection is that it's slower than other methods.
NetBSD can use at most 115200 bit/s, making it a lot slower than e.g.
Ethernet's minimum 10 Mbit/s.
There are two possible protocols to connect a host running NetBSD to another
host using a serial line (possibly over a phone-line):
* Serial Line IP (SLIP)
* Point to Point Protocol (PPP)
The choice here depends on whether you use a dial-up connection through a modem
or if you use a static connection (null-modem or leased line). If you dial up
for your IP connection, it's wise to use PPP as it offers some possibilities to
auto-negotiate IP-addresses and routes, which can be quite painful to do by
hand. If you want to connect to another machine which is directly connected,
use SLIP, as this is supported by about every operating system and more easy to
set up with fixed addresses and routes.
PPP on a direct connection is a bit difficult to setup, as it's easy to timeout
the initial handshake; with SLIP, there's no such initial handshake, i.e. you
start up one side, and when the other site has its first packet, it will send
it over the line.
[RFC1331] and [RFC1332] describe PPP and TCP/IP over PPP. SLIP is defined in [
RFC1055].
25.4. ÔCP/IP Address Format
TCP/IP uses 4-byte (32-bit) addresses in the current implementations (IPv4),
also called IP-numbers (Internet-Protocol numbers), to address hosts.
TCP/IP allows any two machines to communicate directly. To permit this all
hosts on a given network must have a unique IP address. To assure this, IP
addresses are administrated by one central organisation, the InterNIC. They
give certain ranges of addresses (network-addresses) directly to sites which
want to participate in the internet or to internet-providers, which give the
addresses to their customers.
If your university or company is connected to the Internet, it has (at least)
one such network-address for its own use, usually not assigned by the InterNIC
directly, but rather through an Internet Service Provider (ISP).
If you just want to run your private network at home, see below on how to "
build" your own IP addresses. However, if you want to connect your machine to
the (real :-) Internet, you should get an IP addresses from your local
network-administrator or -provider.
IP addresses are usually written in "dotted quad"-notation - the four bytes are
written down in decimal (most significant byte first), separated by dots. For
example, 132.199.15.99 would be a valid address. Another way to write down
IP-addresses would be as one 32-bit hex-word, e.g. 0x84c70f63. This is not as
convenient as the dotted-quad, but quite useful at times, too. (See below!)
Being assigned a network means nothing else but setting some of the
above-mentioned 32 address-bits to certain values. These bits that are used for
identifying the network are called network-bits. The remaining bits can be used
to address hosts on that network, therefore they are called host-bits.
Figure5.1, "IPv4-addresses are divided into more significant network- and
less significant hostbits" illustrates the separation.
Figure5.1. ÉPv4-addresses are divided into more significant network- and less
significant hostbits
IPv4-addresses are divided into more significant network- and less significant
hostbits
In the above example, the network-address is 132.199.0.0 (host-bits are set to
0 in network-addresses) and the host's address is 15.99 on that network.
How do you know that the host's address is 16 bit wide? Well, this is assigned
by the provider from which you get your network-addresses. In the classless
inter-domain routing (CIDR) used today, host fields are usually between as
little as 2 to 16 bits wide, and the number of network-bits is written after
the network address, separated by a "/", e.g. 132.199.0.0/16 tells that the
network in question has 16 network-bits. When talking about the "size" of a
network, it's usual to only talk about it as "/16", "/24", etc.
Before CIDR was used, there used to be four classes of networks. Each one
starts with a certain bit-pattern identifying it. Here are the four classes:
* Class A starts with "0" as most significant bit. The next seven bits of a
class A address identify the network, the remaining 24 bit can be used to
address hosts. So, within one class A network there can be 2^24 hosts. It's
not very likely that you (or your university, or company, or whatever) will
get a whole class A address.
The CIDR notation for a class A network with its eight network bits is an "
/8".
* Class B starts with "10" as most significant bits. The next 14 bits are
used for the networks address and the remaining 16 bits can be used to
address more than 65000 hosts. Class B addresses are very rarely given out
today, they used to be common for companies and universities before IPv4
address space went scarce.
The CIDR notation for a class B network with its 16 network bits is an "/16
".
Returning to our above example, you can see that 132.199.15.99 (or
0x84c70f63, which is more appropriate here!) is on a class B network, as
0x84... = 1000... (base 2).
Therefore, the address 132.199.15.99 can be split into an network-address
of 132.199.0.0 and a host-address of 15.99.
* Class C is identified by the MSBs being "110", allowing only 256 (actually:
only 254, see below) hosts on each of the 2^21 possible class C networks.
Class C addresses are usually found at (small) companies.
The CIDR notation for a class C network with its 24 network bits is an "/24
".
* There are also other addresses, starting with "111". Those are used for
special purposes (e. g. multicast-addresses) and are not of interest here.
Please note that the bits which are used for identifying the network-class are
part of the network-address.
When separating host-addresses from network-addresses, the "netmask" comes in
handy. In this mask, all the network-bits are set to "1", the host-bits are "0"
. Thus, putting together IP-address and netmask with a logical AND-function,
the network-address remains.
To continue our example, 255.255.0.0 is a possible netmask for 132.199.15.99.
When applying this mask, the network-address 132.199.0.0 remains.
For addresses in CIDR notation, the number of network-bits given also says how
many of the most significant bits of the address must be set to "1" to get the
netmask for the corresponding network. For classful addressing, every
network-class has a fixed default netmask assigned:
* Class A (/8): default-netmask: 255.0.0.0, first byte of address: 1-127
* Class B (/16): default-netmask: 255.255.0.0, first byte of address: 128-191
* Class C (/24): default-netmask: 255.255.255.0, first byte of address:
192-223
Another thing to mention here is the "broadcast-address". When sending to this
address, all hosts on the corresponding network will receive the message sent.
The broadcast address is characterized by having all host-bits set to "1".
Taking 132.199.15.99 with its netmask 255.255.0.0 again, the broadcast-address
would result in 132.199.255.255.
You'll ask now: But what if I want a host's address to be all bits "0" or "1"?
Well, this doesn't work, as network- and broadcast-address must be present!
Because of this, a class B (/16) network can contain at most 2^16-2 hosts, a
class C (/24) network can hold no more than 2^8-2 = 254 hosts.
Besides all those categories of addresses, there's the special IP-address
127.0.0.1 which always refers to the "local" host, i.e. if you talk to
127.0.0.1 you'll talk to yourself without starting any network-activity. This
is sometimes useful to use services installed on your own machine or to play
around if you don't have other hosts to put on your network.
Let's put together the things we've introduced in this section:
IP-address
32 bit-address, with network- and host-bits.
Network-address
IP-address with all host bits set to "0".
Netmask
32-bit mask with "1" for network- and "0" for host-bits.
Broadcast
IP-address with all host bits set "1".
localhost's address
The local host's IP address is always 127.0.0.1.
25.5. Óubnetting and Routing
After talking so much about netmasks, network-, host- and other addresses, I
have to admit that this is not the whole truth.
Imagine the situation at your university, which usually has a class B (/16)
address, allowing it to have up to 2^16 ~= 65534 hosts on that net. Maybe it
would be a nice thing to have all those hosts on one single network, but it's
simply not possible due to limitations in the transport media commonly used
today.
For example, when using thinwire ethernet, the maximum length of the cable is
185 meters. Even with repeaters in between, which refresh the signals, this is
not enough to cover all the locations where machines are located. Besides that,
there is a maximum number of 1024 hosts on one ethernet wire, and you'll lose
quite a bit of performance if you go to this limit.
So, are you hosed now? Having an address which allows more than 60000 hosts,
but being bound to media which allows far less than that limit?
Well, of course not! :-)
The idea is to divide the "big" class B net into several smaller networks,
commonly called sub-networks or simply subnets. Those subnets are only allowed
to have, say, 254 hosts on them (i.e. you divide one big class B network into
several class C networks!).
To do this, you adjust your netmask to have more network- and less host-bits on
it. This is usually done on a byte-boundary, but you're not forced to do it
there. So, commonly your netmask will not be 255.255.0.0 as supposed by a class
B network, but it will be set to 255.255.255.0.
In CIDR notation, you now write a "/24" instead of the "/16" to show that 24
bits of the address are used for identifying the network and subnet, instead of
the 16 that were used before.
This gives you one additional network-byte to assign to each (physical!)
network. All the 254 hosts on that subnet can now talk directly to each other,
and you can build 256 such class C nets. This should fit your needs.
To explain this better, let's continue our above example. Say our host
132.199.15.99 (I'll call him dusk from now; we'll talk about assigning
hostnames later) has a netmask of 255.255.255.0 and thus is on the subnet
132.199.15.0/24. Let's furthermore introduce some more hosts so we have
something to play around with, see Figure5.2, "Our demo-network".
Figure5.2. Ïur demo-network
Our demo-network
In the above network, dusk can talk directly to dawn, as they are both on the
same subnet. (There are other hosts attached to the 132.199.15.0/24-subnet but
they are not of importance for us now)
But what if dusk wants to talk to a host on another subnet?
Well, the traffic will then go through one or more gateways (routers), which
are attached to two subnets. Because of this, a router always has two different
addresses, one for each of the subnets it is on. The router is functionally
transparent, i.e. you don't have to address it to reach hosts on the "other"
side. Instead, you address that host directly and the packets will be routed to
it correctly.
Example. Let's say dusk wants to get some files from the local ftp-server. As
dusk can't reach ftp directly (because it's on a different subnet), all its
packets will be forwarded to its "defaultrouter" rzi (132.199.15.1), which
knows where to forward the packets.
Dusk knows the address of its defaultrouter in its network (rzi, 132.199.15.1),
and it will forward any packets to it which are not on the same subnet, i.e. it
will forward all IP-packets in which the third address-byte isn't 15.
The (default)router then gives the packets to the appropriate host, as it's
also on the FTP-server's network.
In this example, all packets are forwarded to the 132.199.1.0/24-network,
simply because it's the network's backbone, the most important part of the
network, which carries all the traffic that passes between several subnets.
Almost all other networks besides 132.199.15.0/24 are attached to the backbone
in a similar manner.
But what if we had hooked up another subnet to 132.199.15.0/24 instead of
132.199.1.0/24? Maybe something the situation displayed in Figure5.3,
"Attaching one subnet to another one".
Figure5.3. Áttaching one subnet to another one
Attaching one subnet to another one
When we now want to reach a host which is located in the 132.199.16.0/24-subnet
from dusk, it won't work routing it to rzi, but you'll have to send it directly
to route2 (132.199.15.2). Dusk will have to know to forward those packets to
route2 and send all the others to rzi.
When configuring dusk, you tell it to forward all packets for the 132.199.16.0/
24-subnet to route2, and all others to rzi. Instead of specifying this default
as 132.199.1.0/24, 132.199.2.0/24, etc., 0.0.0.0 can be used to set the
default-route.
Returning to Figure5.2, "Our demo-network", there's a similar problem when
dawn wants to send to noon, which is connected to dusk via a serial line
running. When looking at the IP-addresses, noon seems to be attached to the
132.199.15.0-network, but it isn't really. Instead, dusk is used as gateway,
and dawn will have to send its packets to dusk, which will forward them to noon
then. The way dusk is forced into accepting packets that aren't destined at it
but for a different host (noon) instead is called "proxy arp".
The same goes when hosts from other subnets want to send to noon. They have to
send their packets to dusk (possibly routed via rzi),
25.6. Îame Service Concepts
In the previous sections, when we talked about hosts, we referred to them by
their IP-addresses. This was necessary to introduce the different kinds of
addresses. When talking about hosts in general, it's more convenient to give
them "names", as we did when talking about routing.
Most applications don't care whether you give them an IP address or a hostname.
However, they'll use IP addresses internally, and there are several methods for
them to map hostnames to IP addresses, each one with its own way of
configuration. In this section we'll introduce the idea behind each method, in
the next chapter, we'll talk about the configuration-part.
The mapping from hostnames (and domainnames) to IP-addresses is done by a piece
of software called the "resolver". This is not an extra service, but some
library routines which are linked to every application using networking-calls.
The resolver will then try to resolve (hence the name ;-) the hostnames you
give into IP addresses. See [RFC1034] and [RFC1035] for details on the
resolver.
Hostnames are usually up to 256 characters long, and contain letters, numbers
and dashes ("-"); case is ignored.
Just as with networks and subnets, it's possible (and desirable) to group hosts
into domains and subdomains. When getting your network-address, you usually
also obtain a domainname by your provider. As with subnets, it's up to you to
introduce subdomains. Other as with IP-addresses, (sub)domains are not directly
related to (sub)nets; for example, one domain can contain hosts from several
subnets.
Figure5.2, "Our demo-network" shows this: Both subnets 132.199.1.0/24 and
132.199.15.0/24 (and others) are part of the subdomain "rz.uni-regensburg.de".
The domain the University of Regensburg got from its IP-provider is "
uni-regensburg.de" (".de" is for Deutschland, Germany), the subdomain "rz" is
for Rechenzentrum, computing center.
Hostnames, subdomain- and domainnames are separated by dots ("."). It's also
possible to use more than one stage of subdomains, although this is not very
common. An example would be fox_in.socs.uts.edu.au.
A hostname which includes the (sub)domain is also called a fully qualified
domain name (FQDN). For example, the IP-address 132.199.15.99 belongs to the
host with the FQDN dusk.rz.uni-regensburg.de.
Further above I told you that the IP-address 127.0.0.1 always belongs to the
local host, regardless what's the "real" IP-address of the host. Therefore,
127.0.0.1 is always mapped to the name "localhost".
The three different ways to translate hostnames into IP addresses are: /etc/
hosts, the Domain Name Service (DNS) and the Network Information Service (NIS).
25.6.1.etc/hosts
The first and simplest way to translate hostnames into IP-addresses is by using
a table telling which IP address belongs to which hostname(s). This table is
stored in the file /etc/hosts and has the following format:
IP-address hostname [nickname [...]]
Lines starting with a hash mark ("#") are treated as comments. The other lines
contain one IP-address and the corresponding hostname(s).
It's not possible for a hostname to belong to several IP addresses, even if I
made you think so when talking about routing. rzi for example has really two
distinct names for each of its two addresses: rzi and rzia (but please don't
ask me which name belongs to which address!).
Giving a host several nicknames can be convenient if you want to specify your
favorite host providing a special service with that name, as is commonly done
with FTP-servers. The first (leftmost) name is usually the real (canonical)
name of the host.
Besides giving nicknames, it's also convenient to give a host's full name
(including domain) as its canonical name, and using only its hostname (without
domain) as a nickname.
Important: There must be an entry mapping localhost to 127.0.0.1 in /etc/hosts!
25.6.2. Äomain Name Service (DNS)
/etc/hosts bears an inherent problem, especially in big networks: when one host
is added or one host's address changes, all the /etc/hosts files on all
machines have to be changed! This is not only time-consuming, it's also very
likely that there will be some errors and inconsistencies, leading to problems.
Another approach is to hold only one hostnames-table (-database) for a network,
and make all the clients query that "nameserver". Updates will be made only on
the nameserver.
This is the basic idea behind the Domain Name Service (DNS).
Usually, there's one nameserver for each domain (hence DNS), and every host
(client) in that domain knows which domain it is in and which nameserver to
query for its domain.
When the DNS gets a query about a host which is not in its domain, it will
forward the query to a DNS which is either the DNS of the domain in question or
knows which DNS to ask for the specified domain. If the DNS forwarded the query
doesn't know how to handle it, it will forward that query again to a DNS one
step higher. This is not ad infinitum, there are several "root"-servers, which
know about any domain.
See Chapter8, The Domain Name System for details on DNS.
25.6.3. Îetwork Information Service (NIS/YP)
Yellow Pages (YP) was invented by Sun Microsystems. The name has been changed
into Network Information Service (NIS) because YP was already a trademark of
the British telecom. So, when I'm talking about NIS you'll know what I mean. ;
-)
There are quite some configuration files on a Unix-system, and often it's
desired to maintain only one set of those files for a couple of hosts. Those
hosts are grouped together in a NIS-domain (which has nothing to do with the
domains built by using DNS!) and are usually contained in one workstation
cluster.
Examples for the config-files shared among those hosts are /etc/passwd, /etc/
group and - last but not least - /etc/hosts.
So, you can "abuse" NIS for getting a unique name-to-address-translation on all
hosts throughout one (NIS-)domain.
There's only one drawback, which prevents NIS from actually being used for that
translation: In contrast to the DNS, NIS provides no way to resolve hostnames
which are not in the hosts-table. There's no hosts "one level up" which the
NIS-server can query, and so the translation will fail! Suns NIS+ takes
measures against that problem, but as NIS+ is only available on
Solaris-systems, this is of little use for us now.
Don't get me wrong: NIS is a fine thing for managing e.g. user-information (/
etc/passwd, ...) in workstation-clusters, it's simply not too useful for
resolving hostnames.
25.6.4. Ïther
The name resolving methods described above are what's used commonly today to
resolve hostnames into IP addresses, but they aren't the only ones. Basically,
every database mechanism would do, but none is implemented in NetBSD. Let's
have a quick look what you may encounter.
With NIS lacking hierarchy in data structures, NIS+ is intended to help out in
that field. Tables can be setup in a way so that if a query cannot be answered
by a domain's server, there can be another domain "above" that might be able to
do so. E.g. you could choose to have a domain that lists all the hosts (users,
groups, ...) that are valid in the whole company, one that defines the same for
each division, etc. NIS+ is not used a lot today, even Sun went back to ship
back NIS by default.
Last century, the X.500 standard was designed to accommodate both simple
databases like /etc/hosts as well as complex, hierarchical systems as can be
found e.g. in DNS today. X.500 wasn't really a success, mostly due to the fact
that it tried to do too much at the same time. A cut-down version is available
today as the Lightweight Directory Access Protocol (LDAP), which is becoming
popular in the last years to manage data like users but also hosts and others
in small to medium sized organisations.
25.7. ÉPv6
25.7.1.What good is IPv6?
When telling people to migrate from IPv4 to IPv6, the question you usually hear
is "why?". There are actually a few good reasons to move to the new version:
* Bigger address space
* Support for mobile devices
* Built-in security
25.7.1.1.Bigger Address Space
The bigger address space that IPv6 offers is the most obvious enhancement it
has over IPv4. While today's internet architecture is based on 32-bit wide
addresses, the new version has 128 bit available for addressing. Thanks to the
enlarged address space, work-arounds like NAT don't have to be used any more.
This allows full, unconstrained IP connectivity for today's mobile phones and
IoT devices.
25.7.1.2.Mobility
When mentioning mobile devices and IP, another important point to note is that
some special protocol is needed to support mobility, and implementing this
protocol - called "Mobile IP" - is one of the requirements for every IPv6
stack. Thus, if you have IPv6 going, you have support for roaming between
different networks, with everyone being updated when you leave one network and
enter the other one. Support for roaming is possible with IPv4 too, but there
are a number of hoops that need to be jumped in order to get things working.
With IPv6, there's no need for this, as support for mobility was one of the
design requirements for IPv6. See [RFC3024] for some more information on the
issues that need to be addressed with Mobile IP on IPv4.
25.7.1.3.Security
Besides support for mobility, security was another requirement for the
successor to today's Internet Protocol version. As a result, IPv6 protocol
stacks are required to include IPsec. IPsec allows authentication, encryption
and compression of any IP traffic. Unlike application level protocols like SSL
or SSH, all IP traffic between two nodes can be handled, without adjusting any
applications. The benefit of this is that all applications on a machine can
benefit from encryption and authentication, and that policies can be set on a
per-host (or even per-network) base, not per application/service. An
introduction to IPsec with a roadmap to the documentation can be found in [
RFC2411], the core protocol is described in [RFC2401].
25.7.2.Changes to IPv4
After giving a brief overview of all the important features of IPv6, we'll go
into the details of the basics of IPv6 here. A brief understanding of how IPv4
works is assumed, and the changes in IPv6 will be highlighted. Starting with
IPv6 addresses and how they're split up we'll go into the various types of
addresses there are, what became of broadcasts, then after discussing the IP
layer go into changes for name resolving and what's new in DNS for IPv6.
25.7.2.1.Addressing
An IPv4 address is a 32 bit value, that's usually written in "dotted quad"
representation, where each "quad" represents a byte value between 0 and 255,
for example:
127.0.0.1
This allows a theoretical number of 2^32 or ~4 billion hosts to be connected on
the internet today. Due to grouping, not all addresses are available today.
IPv6 addresses use 128 bit, which results in 2^128 theoretically addressable
hosts. This allows for a Really Big number of machines to addressed, and it
sure fits all of today's requirements plus all those nifty PDAs and cell phones
with IP phones in the near future without any sweat. When writing IPv6
addresses, they are usually divided into groups of 16 bits written as four hex
digits, and the groups are separated by colons. An example is:
fe80::2a0:d2ff:fea5:e9f5
This shows a special thing - a number of consecutive zeros can be abbreviated
by a single "::" once in the IPv6 address. The above address is thus equivalent
to fe80:0:00:000:2a0:d2ff:fea5:e9f5 - leading zeros within groups can be
omitted, and only one "::" can be used in an IPv6 address.
To make addresses manageable, they are split in two parts, which are the bits
identifying the network a machine is on, and the bits that identify a machine
on a (sub)network. The bits are known as netbits and hostbits, and in both IPv4
and IPv6, the netbits are the "left", most significant bits of an IP address,
and the host bits are the "right", least significant bits, as shown in
Figure5.4, "IPv6-addresses are divided into more significant network- and
less significant hostbits, too".
Figure5.4. ÉPv6-addresses are divided into more significant network- and less
significant hostbits, too
IPv6-addresses are divided into more significant network- and less significant
hostbits, too
In IPv4, the border is drawn with the aid of the netmask, which can be used to
mask all net/host bits. Typical examples are 255.255.0.0 that uses 16 bit for
addressing the network, and 16 bit for the machine, or 255.255.255.0 which
takes another 8 bit to allow addressing 256 subnets on e.g. a class B net.
When addressing switched from classful addressing to CIDR routing, the borders
between net and host bits stopped being on 8 bit boundaries, and as a result
the netmasks started looking ugly and not really manageable. As a replacement,
the number of network bits is used for a given address, to denote the border,
e.g.
10.0.0.0/24
is the same as a netmask of 255.255.255.0 (24 1-bits). The same scheme is used
in IPv6:
2001:638:a01:2::/64
tells us that the address used here has the first (leftmost) 64 bits used as
the network address, and the last (rightmost) 64 bits are used to identify the
machine on the network. The network bits are commonly referred to as (network)
"prefix", and the "prefixlen" here would be 64 bits.
Common addressing schemes found in IPv4 are the (old) class B and class C nets.
With a class C network (/24), you get 24 bits assigned by your provider, and it
leaves 8 bits to be assigned by you. If you want to add any subnetting to that,
you end up with "uneven" netmasks that are a bit nifty to deal with. Easier for
such cases are class B networks (/16), which only have 16 bits assigned by the
provider, and that allow subnetting, i.e. splitting of the rightmost bits into
two parts. One to address the on-site subnet, and one to address the hosts on
that subnet. Usually, this is done on byte (8 bit) boundaries. Using a netmask
of 255.255.255.0 (or a /24 prefix) allows flexible management even of bigger
networks here. Of course there is the upper limit of 254 machines per subnet,
and 256 subnets.
With 128 bits available for addressing in IPv6, the scheme commonly used is the
same, only the fields are wider. Providers usually assign /48 networks, which
leaves 16 bits for a subnetting and 64 hostbits.
Figure5.5. ÉPv6-addresses have a similar structure to class B addresses
IPv6-addresses have a similar structure to class B addresses
Now while the space for network and subnets here is pretty much ok, using 64
bits for addressing hosts seems like a waste. It's unlikely that you will want
to have several billion hosts on a single subnet, so what is the idea behind
this?
The idea behind fixed width 64 bit wide host identifiers is that they aren't
assigned manually as it's usually done for IPv4 nowadays. Instead, IPv6 host
addresses are recommended (not mandatory!) to be built from so-called EUI64
addresses. EUI64 addresses are - as the name says - 64 bit wide, and derived
from MAC addresses of the underlying network interface. E.g. for ethernet, the
6 byte (48 bit) MAC address is usually filled with the hex bits "fffe" in the
middle and a bit is set to mark the address as unique (which is true for
Ethernet), e.g. the MAC address
01:23:45:67:89:ab
results in the EUI64 address
03:23:45:ff:fe:67:89:ab
which again gives the host bits for the IPv6 address as
::0323:45ff:fe67:89ab
These host bits can now be used to automatically assign IPv6 addresses to
hosts, which supports autoconfiguration of IPv6 hosts - all that's needed to
get a complete IPv6 address is the first (net/subnet) bits, and IPv6 also
offers a solution to assign them automatically.
When on a network of machines speaking IP, there's usually one router which
acts as the gateway to outside networks. In IPv6 land, this router will send "
router advertisement" information, which clients are expected to either receive
during operation or to solicit upon system startup. The router advertisement
information includes data on the router's address, and which address prefix it
routes. With this information and the host-generated EUI64 address, an
IPv6-host can calculate its IP address, and there is no need for manual address
assignment. Of course routers still need some configuration.
The router advertisement information they create are part of the Neighbor
Discovery Protocol (NDP, see [RFC2461]), which is the successor to IPv4's ARP
protocol. In contrast to ARP, NDP does not only do lookup of IPv6 addresses for
MAC addresses (the neighbor solicitation/advertisement part), but also does a
similar service for routers and the prefixes they serve, which is used for
autoconfiguration of IPv6 hosts as described in the previous paragraph.
25.7.2.2.Multiple Addresses
In IPv4, a host usually has one IP address per network interface or even per
machine if the IP stack supports it. Only very rare applications like web
servers result in machines having more than one IP address. In IPv6, this is
different. For each interface, there is not only a globally unique IP address,
but there are two other addresses that are of interest: The link local address,
and the site local address. The link local address has a prefix of fe80::/64,
and the host bits are built from the interface's EUI64 address. The link local
address is used for contacting hosts and routers on the same network only, the
addresses are not visible or reachable from different subnets. If wanted,
there's the choice of either using global addresses (as assigned by a
provider), or using site local addresses. Site local addresses are assigned the
network address fec0::/10, and subnets and hosts can be addressed just as for
provider-assigned networks. The only difference is, that the addresses will not
be visible to outside machines, as these are on a different network, and their
"site local" addresses are in a different physical net (if assigned at all). As
with the 10/8 network in IPv4, site local addresses can be used, but don't have
to. For IPv6 it's most common to have hosts assigned a link-local and a global
IP address. Site local addresses are rather uncommon today, and are no
substitute for globally unique addresses if global connectivity is required.
25.7.2.3.Multicasting
In IP land, there are three ways to talk to a host: unicast, broadcast and
multicast. The most common one is by talking to it directly, using its unicast
address. In IPv4, the unicast address is the "normal" IP address assigned to a
single host, with all address bits assigned. The broadcast address used to
address all hosts in the same IP subnet has the network bits set to the network
address, and all host bits set to "1" (which can be easily done using the
netmask and some bit operations). Multicast addresses are used to reach a
number of hosts in the same multicast group, which can be machines spread over
the whole internet. Machines must join multicast groups explicitly to
participate, and there are special IPv4 addresses used for multicast addresses,
allocated from the 224/8 subnet. Multicast isn't used very much in IPv4, and
only few applications like the MBone audio and video broadcast utilities use
it.
In IPv6, unicast addresses are used the same as in IPv4, no surprise there -
all the network and host bits are assigned to identify the target network and
machine. Broadcasts are no longer available in IPv6 in the way they were in
IPv4, this is where multicasting comes into play. Addresses in the ff::/8
network are reserved for multicast applications, and there are two special
multicast addresses that supersede the broadcast addresses from IPv4. One is
the "all routers" multicast address, the others is for "all hosts". The
addresses are specific to the subnet, i.e. a router connected to two different
subnets can address all hosts/routers on any of the subnets it's connected to.
Addresses here are:
* ff0X::1 for all hosts and
* ff0X::2 for all routers,
where "X" is the scope ID of the link here, identifying the network. Usually
this starts from "1" for the "node local" scope, "2" for the first link, etc.
Note that it's perfectly ok for two network interfaces to be attached to one
link, thus resulting in double bandwidth:
Figure5.6. Óeveral interfaces attached to a link result in only one scope ID
for the link
Several interfaces attached to a link result in only one scope ID for the link
One use of the "all hosts" multicast is in the neighbor solicitation code of
NDP, where any machine that wants to communicate with another machine sends out
a request to the "all hosts" group, and the machine in question is expected to
respond.
25.7.2.4.Name Resolving in IPv6
After talking a lot about addressing in IPv6, anyone still here will hope that
there's a proper way to abstract all these long & ugly IPv6 addresses with some
nice hostnames as one can do in IPv4, and of course there is.
Hostname to IP address resolving in IPv4 is usually done in one of three ways:
using a simple table in /etc/hosts, by using the Network Information Service
(NIS, formerly YP) or via the Domain Name System (DNS).
As of this writing, NIS/NIS+ over IPv6 is currently only available on Solaris
8, for both database contents and transport, using a RPC extension.
Having a simple address<->name map like /etc/hosts is supported in all IPv6
stacks. With the KAME implementation used in NetBSD, /etc/hosts contains IPv6
addresses as well as IPv4 addresses. A simple example is the "localhost" entry
in the default NetBSD installation:
127.0.0.1 localhost
::1 localhost
For DNS, there are no fundamentally new concepts. IPv6 name resolving is done
with AAAA records that - as the name implies - point to an entity that's four
times the size of an A record. The AAAA record takes a hostname on the left
side, just as A does, and on the right side there's an IPv6 address, e.g.
noon IN AAAA 3ffe:400:430:2:240:95ff:fe40:4385
For reverse resolving, IPv4 uses the in-addr.arpa zone, and below that it
writes the bytes (in decimal) in reversed order, i.e. more significant bytes
are more right. For IPv6 this is similar, only that hex digits representing 4
bits are used instead of decimal numbers, and the resource records are also
under a different domain, ip6.int.
So to have the reverse resolving for the above host, you would put into your /
etc/named.conf something like:
zone "0.3.4.0.0.0.4.0.e.f.f.3.IP6.INT" {
type master;
file "db.reverse";
};
and in the zone file db.reverse you put (besides the usual records like SOA and
NS):
5.8.3.4.0.4.e.f.f.f.5.9.0.4.2.0.2.0.0.0 IN PTR noon.ipv6.example.com.
The address is reversed here, and written down one hex digit after the other,
starting with the least significant (rightmost) one, separating the hex digits
with dots, as usual in zone files.
One thing to note when setting up DNS for IPv6 is to take care of the DNS
software version in use. BIND 8.x does understand AAAA records, but it does not
offer name resolving via IPv6. You need BIND 9.x for that. Beyond that, BIND
9.x supports a number of resource records that are currently being discussed
but not officially introduced yet. The most noticeable one here is the A6
record which allows easier provider/prefix changing.
To sum up, this section talked about the technical differences between IPv4 and
IPv6 for addressing and name resolving. Some details like IP header options,
QoS and flows were deliberately left out to not make this document more complex
than necessary.
Chapter6. Óetting up TCP/IP on NetBSD in practice
Table of Contents
26.1. Overview of the network configuration files
26.2. Connecting to common LAN setups
26.2.1. Connecting using IEEE 802.11 (Wi-Fi)
26.3. Manually creating a small LAN
26.4. Connecting to a home/office ISP with PPPoE
26.4.1. Configuring a VLAN
26.4.2. Setting up MSS clamping
26.4.3. Obtaining IPv6 addresses via Prefix Delegation
26.5. Setting up an Internet gateway with NPF
26.6. Setting up a network bridge device
26.6.1. Bridge example
26.7. Ensuring interfaces are initialized in the correct order
26.8. Some useful commands
26.1. Ïverview of the network configuration files
The following is a list of the files used to configure the network. The usage
of these files, some of which have already been met the first chapters, will be
described in the following sections.
/etc/hosts
Local hosts database file. Each line contains information regarding a known
host and contains the internet address, the host's name and the aliases.
Small networks can be configured using only the hosts file, without a name
server. See hosts(5)
/etc/resolv.conf
This file specifies how the routines which provide access to the Internet
Domain Name System should operate. Generally it contains the addresses of
the DNS servers. See resolv.conf(5)
/etc/sysctl.conf
This file is used for configuring kernel settings, e.g. enabling packet
forwarding on a gateway. See sysctl.conf(5).
/etc/ifconfig.xxx
This file is used for the automatic configuration of the network interfaces
at boot, see ifconfig.if(5)
/etc/npf.conf
Contains firewall configuration for the NetBSD Packet Filter, see npf.conf
(5) and /usr/share/examples/npf.
/etc/dhcpcd.conf
Contains configuration for a DHCP client. DHCP is used to automatically get
IPv4 address assignments over Ethernet, but dhcpcd(8) is also used to for
IPv6 Prefix Delegation and DHCPv6. See dhcpcd.conf(5) and /usr/share/
examples/dhcpcd.
/etc/dhcpd.conf
Contains configuration for a DHCP server. DHCP is used to automatically
assign IPv4 addresses to clients. See dhcpd.conf(5) and /usr/share/examples
/dhcpd.
/etc/mygate
Contains the IP address of the gateway. Used to configure a default route
when not using DHCP.
/etc/nsswitch.conf
Name service switch configuration file. It controls how a process looks up
various databases containing information regarding hosts, users, groups,
etc. Specifically, this file defines the order to look up the databases.
For example, the line:
hosts: files dns mdnsd
specifies that the hosts database comes from two sources, files (the local
/etc/hosts file) and DNS, (the Internet Domain Name System) and that the
local files are searched before the DNS.
It is usually not necessary to modify this file except to enable Multicast
DNS.
See nsswitch.conf(5).
/etc/hostapd.conf
Used to configure an IEEE 802.11 (Wi-Fi) wireless access point. See
hostapd.conf(5) and /usr/share/examples/hostapd.
/etc/wpa_supplicant.conf
Used to configure an IEEE 802.11 (Wi-Fi) client. See wpa_supplicant.conf(5)
and /usr/share/examples/wpa_supplicant.
26.2. Ãonnecting to common LAN setups
In Local Area Networks that are centrally managed, one can expect Internet
connectivity being available via some router, a DNS server being available, and
most important, a DHCP server which hands out IP addresses to clients on
request. To make a NetBSD client run in such an environment, it's usually
enough to set
dhcpcd=YES
in /etc/rc.conf, and the IP address will be set automatically, /etc/resolv.conf
will be created and routing setup to the default router.
26.2.1. Ãonnecting using IEEE 802.11 (Wi-Fi)
WPA Supplicant allows connecting to Wi-Fi networks using a password, but also
provides a consistent interface through which to connect to access points.
As well as having dhcpcd(8) running, on a system using Wi-Fi to connect to an
access point, wpa_supplicant(8) must typically be enabled:
ifconfig_iwm0="up"
dhcpcd=YES
wpa_supplicant=YES
At runtime:
# ifconfig iwm0 up
# service dhcpcd start
# service wpa_supplicant start
In this case, our Wi-Fi interface is called iwm0. It is set to up with ifconfig
(8). You can find a list of detected Wi-Fi interfaces with wlanctl(8):
# wlanctl -a
iwm0: mac 10:02:xx:xx:xx:xx bss 00:00:00:00:00:00
The following /etc/wpa_supplicant.conf configures NetBSD to automatically
connect to two access points. More can also be added.
Example6.1.etc/wpa_supplicant.conf
# Allow wpa_cli(8) to configure wpa_supplicant
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel
update_config=1
# Automatically connect to the unprotected network "metalab".
network={
ssid="metalab"
key_mgmt=NONE
priority=100
}
# Automatically connect to the protected network "discord" using the password "XXX".
network={
ssid="discord"
psk="XXX"
}
After adding access points, reload wpa_supplicant(8)'s configuration:
# service wpa_supplicant reload
# service dhcpcd restart
You can use wpa_cli(8) to scan for networks once WPA supplicant is running:
# wpa_cli scan
# wpa_cli scan_results
Selected interface 'iwm0'
16:01:33.578: bssid / frequency / signal level / flags / ssid
xx:xx:xx:xx:xx:xx 5180 91 [WPA2-PSK-CCMP][ESS] FRITZ!Box 1000 EZ
26.3. Íanually creating a small LAN
This section describes how to configure a LAN manually in order to describe the
basics of the networking stack. Usually, this configuration is automatic
through dhcpcd(8), see Section6.2, "Connecting to common LAN setups"
First, the network cards must be installed and connected to a switch or
directly.
Next, check that the network cards are recognized by the kernel, studying the
output of the dmesg command. In the following example the kernel recognized
correctly an NE2000 clone:
...
ne0 at isa0 port 0x280-0x29f irq 9
ne0: NE2000 Ethernet
ne0: Ethernet address 00:c2:dd:c1:d1:21
...
The following command shows the network card's current configuration:
# ifconfig ne0
ne0: flags=8822<BROADCAST,NOTRAILERS,SIMPLEX,MULTICAST> mtu 1500
address: 00:50:ba:aa:a7:7f
media: Ethernet autoselect (10baseT)
inet6 fe80::250:baff:feaa:a77f%ne0 prefixlen 64 scopeid 0x1
The software configuration of the network card is very easy. The IP address "
192.168.1.1" is assigned to the card.
# ifconfig ne0 inet 192.168.1.1 netmask 0xffffff00
Note that the networks 10.0.0.0/8 and 192.168.0.0/16 are reserved for private
networks, which is what we're setting up here.
Repeating the previous command now gives a different result:
# ifconfig ne0
ne0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu 1500
address: 00:50:ba:aa:a7:7f
media: Ethernet autoselect (10baseT)
inet 192.168.1.1 netmask 0xffffff00 broadcast 192.168.1.255
inet6 fe80::250:baff:feaa:a77f%ne0 prefixlen 64 scopeid 0x1
The output of ifconfig has now changed: the IP address is now printed and there
are two new flags, "UP" and "RUNNING" If the interface isn't "UP", it will not
be used by the system to send packets.
The host was given the IP address 192.168.1.1, which belongs to the set of
addresses reserved for internal networks which are not reachable from the
Internet. The configuration is finished and must now be tested; if there is
another active host on the network, a ping can be tried. For example, if
192.168.1.2 is the address of the active host:
# ping 192.168.1.2
PING ape (192.168.1.2): 56 data bytes
64 bytes from 192.168.1.2: icmp_seq=0 ttl=255 time=1.286 ms
64 bytes from 192.168.1.2: icmp_seq=1 ttl=255 time=0.649 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=255 time=0.681 ms
64 bytes from 192.168.1.2: icmp_seq=3 ttl=255 time=0.656 ms
^C
----ape PING Statistics----
4 packets transmitted, 4 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.649/0.818/1.286/0.312 ms
With the current setup, at the next boot it will be necessary to repeat the
configuration of the network card. In order to avoid repeating the card's
configuration at each boot, add the following lines to /etc/rc.conf:
auto_ifconfig=yes
ifconfig_ne0="inet 192.168.1.1 netmask 0xffffff00"
In this example the variable ifconfig_ne0 was set because the network card was
recognized as ne0 by the kernel; if you are using a different adapter,
substitute the appropriate name in place of ne0.
At the next boot the network card will be configured automatically.
If you have a router that is connected to the internet, you can use it as
default router, which will handle all your packets. To do so, set defaultroute
to the router's IP address in /etc/rc.conf:
defaultroute=192.168.0.254
Be sure to use the default router's IP address instead of name, in case your
DNS server is beyond the default router. In that case, the DNS server couldn't
be reached to resolve the default router's hostname and vice versa, creating a
chicken-and-egg problem.
To reach hosts on your local network, and assuming you really have very few
hosts, adjust /etc/hosts to contain the addresses of all the hosts belonging to
the internal network. For example:
Example6.2.etc/hosts
#
# Host Database
# This file should contain the addresses and aliases
# for local hosts that share this file.
# It is used only for "ifconfig" and other operations
# before the nameserver is started.
#
#
127.0.0.1 localhost
::1 localhost
#
# RFC 1918 specifies that these networks are "internal".
# 10.0.0.0 10.255.255.255
# 172.16.0.0 172.31.255.255
# 192.168.0.0 192.168.255.255
192.168.1.1 ape.insetti.net ape
192.168.1.2 vespa.insetti.net vespa
192.168.1.0 insetti.net
To configure a machine as DNS client, you need to edit /etc/resolv.conf, and
enter the DNS server's address, in addition to an optional domain name that
will be appended to hosts with no domain, in order to create a FQDN for
resolving. Assuming your DNS server's IP address is 192.168.1.2 and it is setup
to serve for "home.net", put the following into /etc/resolv.conf:
# /etc/resolv.conf
domain home.net
nameserver 192.168.1.2
Summing up, to configure the network the following must be done: the network
adapters must be installed and physically connected. Next they must be
configured (with ifconfig) and, finally, the file /etc/rc.conf must be modified
to configure the interface and possibly default router, and /etc/resolv.conf
and /etc/nsswitch.conf should be adjusted if DNS should be used. This type of
network management is sufficient for small networks without sophisticated
needs.
26.4. Ãonnecting to a home/office ISP with PPPoE
Many home/office ISPs use PPP (point to point protocol) to provide Internet
access to their clients. NetBSD includes pppoe(4) (PPP over Ethernet)
functionality that can be used to connect to a modem which communicates with
the ISP, typically not using Ethernet, allowing NetBSD to be used as a gateway
on small home and office networks.
We start by configuring the kernel for PPPoE use by bumping the tty queue size.
This setting can be made permanent by editing /etc/sysctl.conf:
# sysctl -w kern.tty.qsize=32768
Now, create the interface with ifconfig(8):
# ifconfig pppoe0 create
# ifconfig inet 0.0.0.0 0.0.0.1 down
# ifconfig re0 up
# pppoectl -e re0 pppoe0
We are using our computer's re0 interface to connect to our DSL modem.
Then, configure the PPPoE connection to use our ISP's provided username and
password:
# pppoectl pppoe0 myauthproto=pap 'myauthname=XXX' 'myauthsecret=YYY' hisauthproto=none
We are now ready to test a first connection. Since something may be wrong, we
will restrict retries for now:
# pppoectl pppoe0 max-auth-failure=1
# ifconfig pppoe0 up
# pppoectl -d pppoe0
pppoe0: state = session
Session ID: 0x254f
PADI retries: 0
PADR retries: 0
This example output shows a working setup. The PPPoE session has been
established and is still in use (state = session). We can now check the IP
negotiation of PPP:
# ifconfig pppoe0
pppoe0: flags=8851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST> mtu 1492
inet 117.80.111.85 -> 118.5.113.169 netmask 0xff000000
We can make the configuration permanent by creating /etc/ifconfig.pppoe0:
Example6.3.etc/ifconfig.pppoe0
create
# Mark the physical interface used by this PPPoE interface up
! /sbin/ifconfig re0 up
# Let $int use re0 as its Ethernet interface
! /sbin/pppoectl -e re0 $int
# Configure authentication
! /sbin/pppoectl $int myauthproto=pap 'myauthname=XXX' 'myauthsecret=YYY' hisauthproto=none
# Configure the PPPoE interface itself. These addresses are magic
# meaning we don't care about either address and let the remote
# ppp choose them.
0.0.0.0 0.0.0.1 up
To automatically get a route(8) to the outside world, we use ifwatchd(8).
Create the following scripts:
Example6.4.etc/ppp/ip-up
#!/bin/sh
/sbin/route add default $5
Example6.5.etc/ppp/ip-down
#!/bin/sh
/sbin/route delete default $5
And make them executable by root:
# chmod +x /etc/ppp/ip-up /etc/ppp/ip-down
Now, edit /etc/rc.conf to enable ifwatchd:
ifwatchd=YES
ifwatchd_flags="-u /etc/ppp/ip-up -d /etc/ppp/ip-down pppoe0"
And start the service:
# service ifwatchd start
26.4.1. Ãonfiguring a VLAN
A typical PPPoE connection requires a VLAN ID to be set on the external
interface. On NetBSD this is accomplished by creating a vlan(4) interface:
# ifconfig vlan0 create
# ifconfig vlan0 vlan 6 vlanif pppoe0
Example6.6.etc/ifconfig.vlan0
create
vlan 6 vlanif pppoe0
To ensure that vlan0 is created at the appropriate time, refer to Section6.7,
"Ensuring interfaces are initialized in the correct order".
26.4.2. Óetting up MSS clamping
Some systems behind misconfigured firewalls try to use Path-MTU-Discovery,
while their firewall blocks all ICMP messages. This is an illegal, but not
uncommon configuration. Typically, remote servers with this configuration are
outside of your control, but you might still need to connect to them, e.g. to
do your online banking.
Without special care, such systems will not be able to send larger chunks of
data to a system connected via PPPoE. But there is a workaround: pretend to not
be able to handle large packets, by sending a small MSS (maximum segment size)
option during initial TCP handshake.
For connections originating from your PPPoE connected system, this is
accomplished by setting the sysctl(8) variable net.inet.tcp.mss_ifmtu to 1,
i.e. by adding this to /etc/sysctl.conf:
# Obey interface MTUs when calculating MSS
net.inet.tcp.mss_ifmtu=1
For connections originating from systems behind your PPPoE router, you need to
configure MSS clamping in your firewall, like in this example /etc/npf.conf:
procedure "norm4" {
normalize: "random-id", "max-mss" 1440
}
procedure "norm6" {
normalize: "random-id", "max-mss" 1420
}
group "external" on "pppoe0" {
pass stateful out final family inet4 all apply "norm4"
pass stateful out final family inet6 all apply "norm6"
}
For more information about configuring NPF, see Section6.5, "Setting up an
Internet gateway with NPF"
26.4.3. Ïbtaining IPv6 addresses via Prefix Delegation
To obtain an IPv6 address, the NetBSD kernel must be configured to accept IPv6
router advertisements with sysctl(8):
# sysctl -w net.inet6.ip6.accept_rtadv=1
This setting can be made permanent by editing /etc/sysctl.conf.
Many ISPs implement IPv6 over PPP via prefix delegation. Prefix Delegation can
be configured with dhcpcd(8), for example with this /etc/dhcpcd.conf:
Example6.7.etc/dhcpcd.conf
duid
ipv6only
require dhcp_server_identifier
option interface_mtu
noipv6rs
slaac private
interface pppoe0
option rapid_commit
ipv6rs
iaid 1
ia_na 1
ia_pd 2/::/64 re1/1
With this configuration, running rtadvd(8) on the re1 interface should be
enough to assign IPv6 addresses to clients.
If you still can't get IPv6 working, other things to try are to make sure
ipv6-icmpand and dhcpv6 can pass through your firewall.
26.5. Óetting up an Internet gateway with NPF
npf(7) (NetBSD Packet Filter) is NetBSD's firewall. It can be used to protect a
local network from the dangers of the wider Internet, and can also perform
Network Address Translation (NAT) in order to make sure IPv4 packets reach the
correct destination computer.
Some usage examples of NPF can be found in the subdirectory /usr/share/examples
/npf. Look at the file soho_gw-npf.conf for an example of a configuration for a
small home/office gateway.
In order to use NetBSD as a gateway, the packet forwarding sysctl(8) options
must be enabled. You can add them to /etc/sysctl.conf.
# sysctl -w net.inet.ip.forwarding=1
net.inet.ip.forwarding = 1
# sysctl -w net.inet6.ip6.forwarding=1
net.inet6.ip6.forwarding = 1
And enable NPF in /etc/rc.conf:
npf=YES
The following configuration performs straightforward NAT, using re0 as the
external network and re1 as the internal network interface. If you have
multiple internal network interfaces, you might want to bridge them. See
Section6.6, "Setting up a network bridge device"
Example6.8.etc/npf.conf
$ext_if = "re0"
$int_if = "re1"
$ext_addrs = { ifaddrs($ext_if) }
$localnet = { 192.168.0.1/24 }
# Allow pings.
alg "icmp"
# Perform IPv4 NAT.
map inet4($ext_if) dynamic $localnet -> inet4($ext_if)
group "external" on $ext_if {
# Allow all outbound traffic
pass stateful out all
# Block all incoming traffic
block in all
}
group "internal" on $int_if {
# We trust the internal network.
pass in final all
pass out final all
}
group default {
pass final on lo0 all
block all
}
Usually, you will want to configure dhcpd(8) so clients are automatically
assigned IP addresses in the correct range:
Example6.9.etc/dhcpd.conf
subnet 192.168.0.0 netmask 255.255.255.0 {
option routers 192.168.0.1;
option domain-name-servers 9.9.9.9;
option subnet-mask 192.168.0.0;
range 192.168.0.100 192.168.0.254;
default-lease-time 604800; # default lease 7 days
}
26.6. Óetting up a network bridge device
A bridge can be used to combine different physical networks into one logical
network, i.e. connect them at layer 2 of the ISO-OSI model, not at layer 3,
which is what a router would do. It can allow multiple network interfaces to be
addressed as one. The NetBSD "bridge" driver provides bridge functionality on
NetBSD systems.
26.6.1. Âridge example
In this example two physical networks are going to be combined in one logical
network, 192.168.1.0, using a NetBSD bridge. The NetBSD machine which is going
to act as bridge has two interfaces, ne0 and ne1, which are each connected to
one physical network.
When the system is ready the bridge can be created, this can be done using the
brconfig(8) command. First of a bridge interface has to be created. With the
following ifconfig(8) command the bridge0 interface will be created:
$ ifconfig bridge0 create
Please make sure that at this point both the ne0 and ne1 interfaces are up. The
next step is to add the ne0 and ne1 interfaces to the bridge.
$ brconfig bridge0 add ne0 add ne1 up
This configuration can be automatically set up by creating an /etc/
ifconfig.interface file, in this case /etc/ifconfig.bridge0, with the following
contents:
create
!brconfig $int add ne0 add ne1 up
Note
In NetBSD 10.0 and later, it will become necessary to use vether instead of tap
as a bridge endpoint. vether is unavailable in previous releases.
After setting up the bridge the bridge configuration can be displayed using the
brconfig -a command. Remember that if you want to give the bridge machine an IP
address you can only allocate an IP address to one of the interfaces which are
part of the bridge. A virtual tap(4) interface can also be created and
configured as a bridge endpoint, e.g. in /etc/ifconfig.tap0:
Example6.10.etc/ifconfig.tap0
create
inet 192.168.0.1 netmask 255.255.255.0
up
!ifconfig bridge0 create
!brconfig bridge0 add $int add ne0 add ne1 up
26.7. Ånsuring interfaces are initialized in the correct order
In our previous example Section6.6, "Setting up a network bridge device", we
created a bridge(4) and tap(4) that are dependent upon other networking
interfaces to function. This can present a problem if rc(8) initializes them
before the interfaces they depend upon. Fortunately, it is possible to force a
specific initialization order in /etc/rc.conf:
auto_ifconfig=NO
net_interfaces="ne0 ne1 pppoe0 bridge0 tap0"
With these lines, /etc/ifconfig.ne0 will be read first, and /etc/ifconfig.tap0
last. The same applies if ifconfig_ne0="up" lines are used in /etc/rc.conf
instead of dedicated configuration files.
26.8. Óome useful commands
The following commands can be useful for diagnosing problems:
ifconfig(8)
Displays and can change the configuration of network intefaces.
ping(8)
Attempt to reach a host and measure latency.
netstat(1)
Displays active connections.
npfctl(8)
npfctl show displays the current firewall configuration, npfctl validate
filename can be used to verify a configuration is correct before loading
it.
route(8)
route show displays the routing tables, other commands can be used to
manipulate them.
traceroute(8)
Shows the route followed by the packets to their destination.
sysstat(1)
sysstat ifstat can be used to monitor network interfaces.
tcpdump(8)
Can be used to monitor TCP/IP traffic.
Chapter7. Ôhe Internet Super Server inetd
Table of Contents
27.1. Overview
27.2. What is inetd?
27.3. Configuring inetd - /etc/inetd.conf
27.4. Services - /etc/services
27.5. Protocols - /etc/protocols
27.6. Remote Procedure Calls (RPC) - /etc/rpc
27.7. Allowing and denying hosts - /etc/hosts.{allow,deny}
27.8. Adding a Service
27.9. When to use or not to use inetd
27.10. Other Resources
The "internet super server", or inetd(8), is available on all Unix(like)
systems, providing many of the basic network services available. This chapter
describes the relationship between the daemon and several of the config files
in the /etc/ directory.
27.1. Ïverview
In this document we will look at a simple definition of inetd(8), how several
files that relate to inetd(8) work (not that these files are not related to
other software), how to add a service to inetd(8) and some considerations both
to use inetd(8) for a particular service and times when a service might be
better off running outside of inetd(8).
27.2. ×hat is inetd?
In traditional Unix scenarios, one server (daemon) process watches for
connections on a particular port, and handles incoming requests. Now if a
machine offers many services, many daemon processes would be needed, mostly
running idle but still wasting resources like memory. The internet super
server, inetd, is an approach to this problem. It listens on a number of ports,
and when it receives a request it then determines which program to run to
handle the request and starts an instance of that program.
Following is a very simple diagram to illustrate inetd(8):
pop3 ------ |
|
ftpd------ | ÉNETD ü--- Énternet ÄMZ Ówitch ×hatever
|
ãvsupserver |
In the above diagram you can see the general idea. The inetd(8) process
receives a request and then starts the appropriate server process. What inetd
(8) is doing is software multiplexing. An important note here, regarding
security: On many other UNIX-like systems, a package called tcpwrappers is used
as a security enhancement for inetd(8). On NetBSD the tcpwrapper functionality
is built into inetd(8) using libwrap.
27.3. Ãonfiguring inetd - /etc/inetd.conf
The operation of inetd(8) is controlled by its own config file, surprisingly
named /etc/inetd.conf, see inetd.conf(5). The inetd.conf file basically
provides enabling and mapping of services the systems administrator would like
to have multiplexed through inetd(8), indicating which program should be
started for incoming requests on which port.
inetd.conf(5) is an ascii file containing one service per line, and several
fields per line. The basic field layout is:
service-name socket-type protocol wait/nowait user:group server-program arguments
service-name:
The service name indicates the port inetd(8) should listen on. It is either
a decimal number, or a name matching a service name given in /etc/services.
socket-type:
The communications socket type, the different types are "stream" for a TCP
stream, "dgram" for an UDP service, "raw" for a raw socket, "rdm" for
reliably delivered message and "seqpacket" for a sequenced packet socket.
The most common socket types are "stream" and "dgram".
protocol
The protocol used, mostly "tcp", "tcp6", "udp" and "udp6" for
stream-oriented services via the Transmission Control Protocol, or
datagram-oriented services via the User Datagram Protocol. It is worth
noting that "tcp" and "udp" mean they use the default (currently IPv4),
"tcp4" specifically means communication via IPv4 only, and "tcp6" and
"udp6" are IPv6-only. In addition to those, protocols based on Remote
Procedure Calls (RPC) can be specified as either "rpc/tcp" or "rpc/udp".
wait/nowait
This field tells inetd(8) if it should wait for a server program to return
or to continue processing new connections immediately. Many connections to
server processes require answers after data transfers are complete, where
other types can keep transmitting on a connection continuously, the latter
is a "nowait" and the former "wait". In most cases, this entry corresponds
to the socket-type, for example a streaming connection would (most of the
time) have a "nowait" value in this field.
user[:group]
This field gives the user name and optionally a group name that the server
process which inetd(8) starts up runs as.
server-program
This field is the full path of the program that gets started.
program-arguments
This field contains the argument vector argv[] of the program started,
including the program name and additional arguments the systems
administrator may need to specify for the server program that is started.
That is all a lot to digest and there are other things the systems
administrator can do with some of the fields. Here is a sample line from an
inetd.conf file:
ftp stream tcp nowait root /usr/libexec/ftpd ftpd -ll
From the left, the service-name is "ftp", socket-type is "stream", protocol is
"tcp", inetd(8) won't wait for the server process to terminate ("nowait"), the
process runs as user "root", path is /usr/libexec/ftpd and program name and
arguments are "ftpd -ll". Notice in the last field, the program name is
different from the service-name.
27.4. Óervices - /etc/services
The next file to consider is the service name data base that can be found in /
etc/services. This file basically contains information mapping a service name
to a port number. The format of the /etc/services file is:
service-name port-number/protocol-name [aliases]
"service-name" is the name of the service, "port-number" is the port number
assigned to the service, "protocol-name" is either "tcp" or "udp", and if alias
names for a port are needed, they can be added as "aliases", separated by white
spaces. Comments may be added after a hash mark (#).
Let's take a look at the "ssh" entries as an example:
ssh 22/tcp # Secure Shell
ssh 22/udp
As we can see, from the left, the service name is "ssh", the port number is
"22", the protocols are both "tcp" and "udp". Notice that there is a separate
entry for every protocol a service can use (even on the same port).
27.5. Ðrotocols - /etc/protocols
Another file read by inetd(8) is /etc/protocols. This file has the information
pertaining to DARPA Internet protocols. The format of the protocols name data
base is:
protocol-name number [aliases]
where "protocol-name" describes the payload of an IP packet, e.g. "tcp" or
"udp". "number" is the official protocol number assigned by IANA, and optional
alias names can be added after that.
Let's look at the seventh entry in the /etc/protocols db as an example:
tcp 6 TCP # transmission control protocol
Starting from the left, we see that the protocol name is "tcp", the number is
"6" and the only aliases listed is "TCP", belonging to the Transmission Control
Protocol as indicated by the comment in that line.
27.6. Òemote Procedure Calls (RPC) - /etc/rpc
The rpc program number data base used by services with the "rpc" protocol type
in inetd.conf(5) is kept in /etc/rpc and contains name mappings to rpc program
numbers. The format of the file is:
server-name program-number aliases
For example, here is the nfs entry:
nfs 100003 nfsprog
27.7. Állowing and denying hosts - /etc/hosts.{allow,deny}
As mentioned above, NetBSD's inetd(8) has the tcpwrapper package built in via
the libwrap library. As such, inetd(8) can allow or deny access to each service
on a more fine-grained base than just allowing a service to everyone, or not
enabling it at all. The access control is defined in the files /etc/hosts.allow
and /etc/hosts.deny, see the hosts_access(5) manpage.
Each of the two files contains several lines that describe access restrictions
for a certain server. Access is allowed if permission is given in /etc/
hosts.allow. If the service is not listened in /etc/hosts.allow but in /etc/
hosts.deny, it is denied. If a service is listed in neither file, it is
allowed, giving standard inetd(8) behaviour.
Each line in /etc/hosts.allow and /etc/hosts.deny contains a service either by
name (as given in the field for argv[0] in /etc/inetd.conf, e.g. "ftpd" instead
of "ftp"), or the special service "ALL" which obviously applies to all
services. Following the service name is - separated by a colon - a number of
access restrictions, which can be hostnames, domains, single IP addresses,
whole IP subnets or some other restrictions, please check hosts_access(5) for
all the details.
An example configuration that is mostly open but denies access to services to a
certain host and all machines from a certain domain would look like this:
# /etc/hostname.deny:
ALL: some.host.name, .some.domain
Another example that would be mostly closed, denying access to all but very few
machines would need entries in both /etc/hosts.allow and /etc/hosts.deny. The
entry for /etc/hosts.deny would be:
# /etc/hosts.deny
ALL: ALL
The entry to allow a few hosts would be put into /etc/hosts.allow:
# /etc/hosts.allow
ALL: friend.host.domain otherfriend.otherhost.otherdomain
27.8. Ádding a Service
Many times a systems administrator will find that they need to add a service to
their system that is not already in inetd(8) or they may wish to move a service
to it because it does not get very much traffic. This is usually pretty simple,
so as an example we will look at adding a version of POP3 on a NetBSD system.
In this case we have retrieved and installed the "cucipop" package, which can
be found in pkgsrc/mail/cucipop. This server is pretty simple to use, the only
oddities are different path locations. Since it is POP3 we know it is a stream
oriented connection with "nowait". Running as "root" will be fine, the only
item that is different is the location of the program and the name of the
program itself.
So the first half of the new entry in /etc/inetd.conf looks like this:
pop3 stream tcp nowait root
After installation, pkgsrc deposited cucipop in /usr/pkg/sbin/cucipop. So with
the next field we have:
pop3 stream tcp nowait root /usr/pkg/sbin/cucipop
Last, we want to use the Berkeley mailbox format, so our server program must be
called with the -Y option. This leaves the entire entry looking like so:
pop3 stream tcp nowait root /usr/pkg/sbin/cucipop cucipop -Y
We have added the service named "pop3" to /etc/inetd.conf. Next item to check
is that the system can map the service name to a port number in /etc/services:
# grep ^pop3 /etc/services
pop3 110/tcp # POP version 3
pop3 110/udp
pop3s 995/tcp # pop3 protocol over TLS/SSL (was spop3)
pop3s 995/udp # pop3 protocol over TLS/SSL (was spop3)
The "pop3" entries here are of interest, i.e. they are already contained in the
/etc/services file shipped with NetBSD.
Now, to have inetd(8) use the new entry, we simply restart it using the rc
script:
# sh /etc/rc.d/inetd restart
All done, in most cases, the software you are using has documentation that will
specify the entry, in the off case it does not, sometimes it helps to try and
find something similar to the server program you will be adding. A classic
example of this is a MUD server which has built-in telnet. You can pretty much
borrow the telnet entry and change parts where needed.
27.9. ×hen to use or not to use inetd
The decision to add or move a service into or out of inetd(8) is usually based
on server load. As an example, on most systems the telnet daemon does not
require as many new connections as say a mail server. Most of the time the
administrator has to feel out if a service should be moved.
A good example I have seen is mail services such as smtp and pop. I had setup a
mail server in which pop3 was in inetd(8) and exim was running in standalone, I
mistakenly assumed it would run fine since there was a low amount of users,
namely myself and a diagnostic account. The server was also setup to act as a
backup MX and relay in case another heavily used one went down. When I ran some
tests I discovered a huge time lag for pop connections remotely. This was
because of my steady fetching of mail and the diagnostic user constantly
mailing diagnostics back and forth. In the end I had to move the pop3 service
out of inetd(8).
The reason for moving the service is actually quite interesting. When a
particular service becomes heavily used, of course, it causes a load on the
system. In the case of a service that runs within the inetd(8) meta daemon the
effects of a heavily loaded service can also harm other services that use inetd
(8). If the multiplexor is getting too many requests for one particular
service, it will begin to affect the performance of other services that use
inetd(8). The fix, in a situation like that, is to make the offending service
run outside of inetd(8) so the response time of both the service and inetd(8)
will increase.
27.10. Ïther Resources
Following is some additional reading and information about topics covered in
this document.
NetBSD manual pages:
* inetd(8)
* protocols(5)
* rpc(5)
* services(5)
* hosts_access(5)
Miscellaneous links:
* IANA: Protocol Numbers and Assignment Services
* RFC1700: Assigned Numbers
Chapter8. Ôhe Domain Name System
Table of Contents
28.1. DNS Background and Concepts
28.1.1. Naming Services
28.1.2. The DNS namespace
28.1.3. Resource Records
28.1.4. Delegation
28.1.5. Delegation to multiple servers
28.1.6. Secondaries, Caching, and the SOA record
28.1.7. Name Resolution
28.1.8. Reverse Resolution
28.2. The DNS Files
28.2.1. /etc/named.conf
28.2.2. /etc/namedb/localhost
28.2.3. /etc/namedb/zone.127.0.0
28.2.4. /etc/namedb/diverge.org
28.2.5. /etc/namedb/1.168.192
28.2.6. /etc/namedb/root.cache
28.3. Using DNS
28.4. Setting up a caching only name server
28.4.1. Testing the server
Use of the Domain Name System has been discussed in previous chapters, without
going into detail on the setup of the server providing the service. This
chapter describes setting up a simple, small domain with one Domain Name System
(DNS) nameserver on a NetBSD system. It includes a brief explanation and
overview of the DNS; further information can be obtained from the DNS Resources
Directory (DNSRD) at http://www.dns.net/dnsrd/.
28.1. ÄNS Background and Concepts
The DNS is a widely used naming service on the Internet and other TCP/IP
networks. The network protocols, data and file formats, and other aspects of
the DNS are Internet Standards, specified in a number of RFC documents, and
described by a number of other reference and tutorial works. The DNS has a
distributed, client-server architecture. There are reference implementations
for the server and client, but these are not part of the standard. There are a
number of additional implementations available for many platforms.
28.1.1. Îaming Services
Naming services are used to provide a mapping between textual names and
configuration data of some form. A nameserver maintains this mapping, and
clients request the nameserver to resolve a name into its attached data.
The reader should have a good understanding of basic hosts to IP address
mapping and IP address class specifications, see Section5.6, "Name Service
Concepts".
In the case of the DNS, the configuration data bound to a name is in the form
of standard Resource Records (RR's). These textual names conform to certain
structural conventions.
28.1.2. Ôhe DNS namespace
The DNS presents a hierarchical name space, much like a UNIX filesystem,
pictured as an inverted tree with the root at the top.
TOP-LEVEL .org
ü
MID-LEVEL diverge.org
ß_____________________|________________________
| | |
BOTTOM-LEVEL ótrider.diverge.org óamwise.diverge.org ÷ormtongue.diverge.org
The system can also be logically divided even further if one wishes at
different points. The example shown above shows three nodes on the diverge.org
domain, but we could even divide diverge.org into subdomains such as
"strider.net1.diverge.org", "samwise.net2.diverge.org" and
"wormtongue.net2.diverge.org"; in this case, 2 nodes reside in
"net2.diverge.org" and one in "net1.diverge.org".
There are directories of names, some of which may be sub-directories of further
names. These directories are sometimes called zones. There is provision for
symbolic links, redirecting requests for information on one name to the records
bound to another name. Each name recognised by the DNS is called a Domain Name,
whether it represents information about a specific host, or a directory of
subordinate Domain Names (or both, or something else).
Unlike most filesystem naming schemes, however, Domain Names are written with
the innermost name on the left, and progressively higher-level domains to the
right, all the way up to the root directory if necessary. The separator used
when writing Domain Names is a period, ".".
Like filesystem pathnames, Domain Names can be written in an absolute or
relative manner, though there are some differences in detail. For instance,
there is no way to indirectly refer to the parent domain like with the UNIX ..
directory. Many (but not all) resolvers offer a search path facility, so that
partially-specified names can be resolved relative to additional listed
sub-domains other than the client's own domain. Names that are completely
specified all the way to the root are called Fully Qualified Domain Names or
FQDNs. A defining characteristic of an FQDN is that it is written with a
terminating period. The same name, without the terminating period, may be
considered relative to some other sub-domain. It is rare for this to occur
without malicious intent, but in part because of this possibility, FQDNs are
required as configuration parameters in some circumstances.
On the Internet, there are some established conventions for the names of the
first few levels of the tree, at which point the hierarchy reaches the level of
an individual organisation. This organisation is responsible for establishing
and maintaining conventions further down the tree, within its own domain.
28.1.3. Òesource Records
Resource Records for a domain are stored in a standardised format in an ASCII
text file, often called a zone file. The following Resource Records are
commonly used (a number of others are defined but not often used, or no longer
used). In some cases, there may be multiple RR types associated with a name,
and even multiple records of the same type.
Common DNS Resource Records
A: Address
This record contains the numerical IP address associated with the name.
CNAME: Canonical Name
This record contains the Canonical Name (an FQDN with an associated A
record) of the host name to which this record is bound. This record type is
used to provide name aliasing, by providing a link to another name with
which other appropriate RR's are associated. If a name has a CNAME record
bound to it, it is an alias, and no other RR's are permitted to be bound to
the same name.
It is common for these records to be used to point to hosts providing a
particular service, such as an FTP or HTTP server. If the service must be
moved to another host, the alias can be changed, and the same name will
reach the new host.
PTR: Pointer
This record contains a textual name. These records are bound to names built
in a special way from numerical IP addresses, and are used to provide a
reverse mapping from an IP address to a textual name. This is described in
more detail in Section8.1.8, "Reverse Resolution".
NS: Name Server
This record type is used to delegate a sub-tree of the Domain Name space to
another nameserver. The record contains the FQDN of a DNS nameserver with
information on the sub-domain, and is bound to the name of the sub-domain.
In this manner, the hierarchical structure of the DNS is established.
Delegation is described in more detail in Section8.1.4, "Delegation".
MX: Mail eXchange
This record contains the FQDN for a host that will accept SMTP electronic
mail for the named domain, together with a priority value used to select an
MX host when relaying mail. It is used to indicate other servers that are
willing to receive and spool mail for the domain if the primary MX is
unreachable for a time. It is also used to direct email to a central
server, if desired, rather than to each and every individual workstation.
HINFO: Host Information
Contains two strings, intended for use to describe the host hardware and
operating system platform. There are defined strings to use for some
systems, but their use is not enforced. Some sites, because of security
considerations, do not publicise this information.
TXT: Text
A free-form text field, sometimes used as a comment field, sometimes
overlaid with site-specific additional meaning to be interpreted by local
conventions.
SOA: Start of Authority
This record is required to appear for each zone file. It lists the primary
nameserver and the email address of the person responsible for the domain,
together with default values for a number of fields associated with
maintaining consistency across multiple servers and caching of the results
of DNS queries.
28.1.4. Äelegation
Using NS records, authority for portions of the DNS namespace below a certain
point in the tree can be delegated, and further sub-parts below that delegated
again. It is at this point that the distinction between a domain and a zone
becomes important. Any name in the DNS is called a domain, and the term applies
to that name and to any subordinate names below that one in the tree. The
boundaries of a zone are narrower, and are defined by delegations. A zone
starts with a delegation (or at the root), and encompasses all names in the
domain below that point, excluding names below any subsequent delegations.
This distinction is important for implementation - a zone is a single
administrative entity (with a single SOA record), and all data for the zone is
referred to by a single file, called a zone file. A zone file may contain more
than one period-separated level of the namespace tree, if desired, by including
periods in the names in that zone file. In order to simplify administration and
prevent overly-large zone files, it is quite legal for a DNS server to delegate
to itself, splitting the domain into several zones kept on the same server.
28.1.5. Äelegation to multiple servers
For redundancy, it is common (and often administratively required) that there
be more than one nameserver providing information on a zone. It is also common
that at least one of these servers be located at some distance (in terms of
network topology) from the others, so that knowledge of that zone does not
become unavailable in case of connectivity failure. Each nameserver will be
listed in an NS record bound to the name of the zone, stored in the parent zone
on the server responsible for the parent domain. In this way, those searching
the name hierarchy from the top down can contact any one of the servers to
continue narrowing their search. This is occasionally called walking the tree.
There are a number of nameservers on the Internet which are called root
nameservers. These servers provide information on the very top levels of the
domain namespace tree. These servers are special in that their addresses must
be pre-configured into nameservers as a place to start finding other servers.
Isolated networks that cannot access these servers may need to provide their
own root nameservers.
28.1.6. Óecondaries, Caching, and the SOA record
In order to maintain consistency between these servers, one is usually
configured as the primary server, and all administrative changes are made on
this server. The other servers are configured as secondaries, and transfer the
contents of the zone from the primary. This operational model is not required,
and if external considerations require it, multiple primaries can be used
instead, but consistency must then be maintained by other means. DNS servers
that store Resource Records for a zone, whether they be primary or secondary
servers, are said to be authoritative for the zone. A DNS server can be
authoritative for several zones.
When nameservers receive responses to queries, they can cache the results. This
has a significant beneficial impact on the speed of queries, the query load on
high-level nameservers, and network utilisation. It is also a major contributor
to the memory usage of the nameserver process.
There are a number of parameters that are important to maintaining consistency
amongst the secondaries and caches. The values for these parameters for a
particular domain zone file are stored in the SOA record. These fields are:
Fields of the SOA Record
Serial
A serial number for the zone file. This should be incremented any time the
data in the domain is changed. When a secondary wants to check if its data
is up-to-date, it checks the serial number on the primary's SOA record.
Refresh
A time, in seconds, specifying how often the secondary should check the
serial number on the primary, and start a new transfer if the primary has
newer data.
Retry
If a secondary fails to connect to the primary when the refresh time has
elapsed (for example, if the host is down), this value specifies, in
seconds, how often the connection should be retried.
Expire
If the retries fail to reach the primary within this number of seconds, the
secondary destroys its copies of the zone data file(s), and stops answering
requests for the domain. This stops very old and potentially inaccurate
data from remaining in circulation.
TTL
This field specifies a time, in seconds, that the resource records in this
zone should remain valid in the caches of other nameservers. If the data is
volatile, this value should be short. TTL is a commonly-used acronym, that
stands for "Time To Live".
28.1.7. Îame Resolution
DNS clients are configured with the addresses of DNS servers. Usually, these
are servers which are authoritative for the domain of which they are a member.
All requests for name resolution start with a request to one of these local
servers. DNS queries can be of two forms:
* A recursive query asks the nameserver to resolve a name completely, and
return the result. If the request cannot be satisfied directly, the
nameserver looks in its configuration and caches for a server higher up the
domain tree which may have more information. In the worst case, this will
be a list of pre-configured servers for the root domain. These addresses
are returned in a response called a referral. The local nameserver must
then send its request to one of these servers.
* Normally, this will be an iterative query, which asks the second nameserver
to either respond with an authoritative reply, or with the addresses of
nameservers (NS records) listed in its tables or caches as authoritative
for the relevant zone. The local nameserver then makes iterative queries,
walking the tree downwards until an authoritative answer is found (either
positive or negative) and returned to the client.
In some configurations, such as when firewalls prevent direct IP communications
between DNS clients and external nameservers, or when a site is connected to
the rest of the world via a slow link, a nameserver can be configured with
information about a forwarder. This is an external nameserver to which the
local nameserver should make requests as a client would, asking the external
nameserver to perform the full recursive name lookup, and return the result in
a single query (which can then be cached), rather than reply with referrals.
28.1.8. Òeverse Resolution
The DNS provides resolution from a textual name to a resource record, such as
an A record with an IP address. It does not provide a means, other than
exhaustive search, to match in the opposite direction; there is no mechanism to
ask which name is bound to a particular RR.
For many RR types, this is of no real consequence, however it is often useful
to identify by name the host which owns a particular IP address. Rather than
complicate the design and implementation of the DNS database engine by
providing matching functions in both directions, the DNS utilises the existing
mechanisms and creates a special namespace, populated with PTR records, for IP
address to name resolution. Resolving in this manner is often called reverse
resolution, despite the inaccurate implications of the term.
The manner in which this is achieved is as follows:
* A normal domain name is reserved and defined to be for the purpose of
mapping IP addresses. The domain name used is "in-addr.arpa." which shows
the historical origins of the Internet in the US Government's Defence
Advanced Research Projects Agency's funding program.
* This domain is then subdivided and delegated according to the structure of
IP addresses. IP addresses are often written in decimal dotted quad
notation, where each octet of the 4-octet long address is written in
decimal, separated by dots. IP address ranges are usually delegated with
more and more of the left-most parts of the address in common as the
delegation gets smaller. Thus, to allow delegation of the reverse lookup
domain to be done easily, this is turned around when used with the
hierarchical DNS namespace, which places higher level domains on the right
of the name.
* Each byte of the IP address is written, as an ASCII text representation of
the number expressed in decimal, with the octets in reverse order,
separated by dots and appended with the in-addr.arpa. domain name. For
example, to determine the hostname of a network device with IP address
11.22.33.44, this algorithm would produce the string
"44.33.22.11.in-addr.arpa." which is a legal, structured Domain Name. A
normal nameservice query would then be sent to the nameserver asking for a
PTR record bound to the generated name.
* The PTR record, if found, will contain the FQDN of a host.
One consequence of this is that it is possible for mismatch to occur. Resolving
a name into an A record, and then resolving the name built from the address in
that A record to a PTR record, may not result in a PTR record which contains
the original name. There is no restriction within the DNS that the "reverse"
mapping must coincide with the "forward" mapping. This is a useful feature in
some circumstances, particularly when it is required that more than one name
has an A record bound to it which contains the same IP address.
While there is no such restriction within the DNS, some application server
programs or network libraries will reject connections from hosts that do not
satisfy the following test:
* the state information included with an incoming connection includes the IP
address of the source of the request.
* a PTR lookup is done to obtain an FQDN of the host making the connection
* an A lookup is then done on the returned name, and the connection rejected
if the source IP address is not listed amongst the A records that get
returned.
This is done as a security precaution, to help detect and prevent malicious
sites impersonating other sites by configuring their own PTR records to return
the names of hosts belonging to another organisation.
28.2. Ôhe DNS Files
Now let's look at actually setting up a small DNS enabled network. We will
continue to use the examples mentioned in Chapter6, Setting up TCP/IP on
NetBSD in practice, i.e. we assume that:
* Our IP networking is working correctly
* We have IPNAT working correctly
* Currently all hosts use the ISP for DNS
Our Name Server will be the "strider" host which also runs IPNAT, and our two
clients use "strider" as a gateway. It is not really relevant as to what type
of interface is on "strider", but for argument's sake we will say a 56k dial up
connection.
So, before going any further, let's look at our /etc/hosts file on "strider"
before we have made the alterations to use DNS.
Example8.1. ótrider's /etc/hosts file
127.0.0.1 localhost
192.168.1.1 strider
192.168.1.2 samwise sam
192.168.1.3 wormtongue worm
This is not exactly a huge network, but it is worth noting that the same rules
apply for larger networks as we discuss in the context of this section.
The other assumption we want to make is that the domain we want to set up is
diverge.org, and that the domain is only known on our internal network, and not
worldwide. Proper registration of the nameserver's IP address as primary would
be needed in addition to a static IP. These are mostly administrative issues
which are left out here.
The NetBSD operating system provides a set of config files for you to use for
setting up DNS. Along with a default /etc/named.conf, the following files are
stored in the /etc/namedb directory:
* localhost
* 127
* loopback.v6
* root.cache
You will see modified versions of these files in this section, and I strongly
suggest making a backup copy of the original files for reference purposes.
Note
The examples in this chapter refer to BIND major version 8, however, it should
be noted that format of the name database and other config files are almost
100% compatible between version. The only difference I noticed was that the "
$TTL" information was not required.
28.2.1.etc/named.conf
The first file we want to look at is /etc/named.conf. This file is the config
file for bind (hence the catchy name). Setting up system like the one we are
doing is relatively simple. First, here is what mine looks like:
options {
directory "/etc/namedb";
allow-transfer { 192.168.1.0/24; };
allow-query { 192.168.1.0/24; };
listen-on port 53 { 192.168.1.1; };
};
zone "localhost" {
type master;
notify no;
file "localhost";
};
zone "127.IN-ADDR.ARPA" {
type master;
notify no;
file "127";
};
zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.int" {
type master;
file "loopback.v6";
};
zone "diverge.org" {
type master;
notify no;
file "diverge.org";
};
zone "1.168.192.in-addr.arpa" {
type master;
notify no;
file "1.168.192";
};
zone "." in {
type hint;
file "root.cache";
};
Note that in my named.conf the root (".") section is last, that is because
there is another domain called diverge.org on the internet (I happen to own it)
so I want the resolver to look out on the internet last. This is not normally
the case on most systems.
Another very important thing to remember here is that if you have an internal
setup, in other words no live internet connection and/or no need to do root
server lookups, comment out the root (".") zone. It may cause lookup problems
if a particular client decides it wants to reference a domain on the internet,
which our server couldn't resolve itself.
Looks like a pretty big mess, upon closer examination it is revealed that many
of the lines in each section are somewhat redundant. So we should only have to
explain them a few times.
Lets go through the sections of named.conf:
28.2.1.1. ïptions
This section defines some global parameters, most noticeable is the location of
the DNS tables, on this particular system, they will be put in /etc/namedb as
indicated by the "directory" option.
Following are the rest of the params:
allow-transfer
This option lists which remote DNS servers acting as secondaries are
allowed to do zone transfers, i.e. are allowed to read all DNS data at
once. For privacy reasons, this should be restricted to secondary DNS
servers only.
allow-query
This option defines hosts from what network may query this name server at
all. Restricting queries only to the local network (192.168.1.0/24)
prevents queries arriving on the DNS server's external interface, and
prevent possible privacy issues.
listen-on port
This option defined the port and associated IP addresses this server will
run named(8) on. Again, the "external" interface is not listened here, to
prevent queries getting received from "outside".
The rest of the named.conf file consists of "zone"s. A zone is an area that can
have items to resolve attached, e.g. a domain can have hostnames attached to
resolve into IP addresses, and a reverse-zone can have IP addresses attached
that get resolved back into hostnames. Each zone has a file associated with it,
and a table within that file for resolving that particular zone. As is readily
apparent, their format in named.conf is strikingly similar, so I will highlight
just one of their records:
28.2.1.2. úone "diverge.org"
type
The type of a zone is usually of type "master" in all cases except for the
root zone "." and for zones that a secondary (backup) service is provided -
the type obviously is "secondary" in the latter case.
notify
Do you want to send out notifications to secondaries when your zone
changes? Obviously not in this setup, so this is set to "no".
file
This option sets the filename in our /etc/namedb directory where records
about this particular zone may be found. For the "diverge.org" zone, the
file /etc/namedb/diverge.org is used.
28.2.2.etc/namedb/localhost
For the most part, the zone files look quite similar, however, each one does
have some unique properties. Here is what the localhost file looks like:
Example8.2. ìocalhost
1|$TTL 3600
2|@ IN SOA strider.diverge.org. root.diverge.org. (
3| 1 ; Serial
4| 8H ; Refresh
5| 2H ; Retry
6| 1W ; Expire
7| 1D) ; Minimum TTL
8| IN NS localhost.
9|localhost. IN A 127.0.0.1
10| IN AAAA ::1
Line by line:
Line 1:
This is the Time To Live for lookups, which defines how long other DNS
servers will cache that value before discarding it. This value is generally
the same in all the files.
Line 2:
This line is generally the same in all zone files except root.cache. It
defines a so-called "Start Of Authority" (SOA) header, which contains some
basic information about a zone. Of specific interest on this line are
"strider.diverge.org." and "root.diverge.org." (note the trailing dots!).
Obviously one is the name of this server and the other is the contact for
this DNS server, in most cases root seems a little ambiguous, it is
preferred that a regular email account be used for the contact information,
with the "@" replaced by a "." (for example, mine would be
"jrf.diverge.org.").
Line 3:
This line is the serial number identifying the "version" of the zone's data
set (file). The serial number should be incremented each time there is a
change to the file, the usual format is to either start with a value of "1"
and increase it for every change, or use a value of "YYYYMMDDNN" to encode
year (YYYY), month (MM), day (DD) and change within one day (NN) in the
serial number.
Line 4:
This is the refresh rate of the server, in this file it is set to once
every 8 hours.
Line 5:
The retry rate.
Line 6:
Lookup expiry.
Line 7:
The minimum Time To Live.
Line 8:
This is the Nameserver line, which uses a "NS" resource record to show that
"localhost" is the only DNS server handing out data for this zone (which is
"@", which indicates the zone name used in the named.conf file, i.e.
"diverge.org") is, well, "localhost".
Line 9:
This is the localhost entry, which uses an "A" resource record to indicate
that the name "localhost" should be resolved into the IP-address 127.0.0.1
for IPv4 queries (which specifically ask for the "A" record).
Line 10:
This line is the IPv6 entry, which returns ::1 when someone asks for an
IPv6-address (by specifically asking for the AAAA record) of "localhost.".
28.2.3.etc/namedb/zone.127.0.0
This is the reverse lookup file (or zone) to resolve the special IP address
127.0.0.1 back to "localhost":
1| $TTL 3600
2| @ IN SOA strider.diverge.org. root.diverge.org. (
3| 1 ; Serial
4| 8H ; Refresh
5| 2H ; Retry
6| 1W ; Expire
7| 1D) ; Minimum TTL
8| IN NS localhost.
9| 1.0.0 IN PTR localhost.
In this file, all of the lines are the same as the localhost zonefile with
exception of line 9, this is the reverse lookup (PTR) record. The zone used
here is "@" again, which got set to the value given in named.conf, i.e.
"127.in-addr.arpa". This is a special "domain" which is used to do
reverse-lookup of IP addresses back into hostnames. For it to work, the four
bytes of the IPv4 address are reserved, and the domain "in-addr.arpa" attached,
so to resolve the IP address "127.0.0.1", the PTR record of
"1.0.0.127.in-addr.arpa" is queried, which is what is defined in that line.
28.2.4.etc/namedb/diverge.org
This zone file is populated by records for all of our hosts. Here is what it
looks like:
1| $TTL 3600
2| @ IN SOA strider.diverge.org. root.diverge.org. (
3| 1 ; serial
4| 8H ; refresh
5| 2H ; retry
6| 1W ; expire
7| 1D ) ; minimum seconds
8| IN NS strider.diverge.org.
9| IN MX 10 strider.diverge.org. ; primary mail server
10| IN MX 20 samwise.diverge.org. ; secondary mail server
11| strider IN A 192.168.1.1
12| samwise IN A 192.168.1.2
13| www IN CNAME samwise.diverge.org.
14| worm IN A 192.168.1.3
There is a lot of new stuff here, so lets just look over each line that is new
here:
Line 9
This line shows our mail exchanger (MX), in this case it is "strider". The
number that precedes "strider.diverge.org." is the priority number, the
lower the number their higher the priority. The way we are setup here is if
"strider" cannot handle the mail, then "samwise" will.
Line 11
CNAME stands for canonical name, or an alias for an existing hostname,
which must have an A record. So we have aliased the following:
www.diverge.org ôo óamwise.diverge.org
The rest of the records are simply mappings of IP address to a full name (A
records).
28.2.5.etc/namedb/1.168.192
This zone file is the reverse file for all of the host records, to map their IP
numbers we use on our private network back into hostnames. The format is
similar to that of the "localhost" version with the obvious exception being the
addresses are different via the different zone given in the named.conf file,
i.e. "0.168.192.in-addr.arpa" here:
1|$TTL 3600
2|@ IN SOA strider.diverge.org. root.diverge.org. (
3| 1 ; serial
4| 8H ; refresh
5| 2H ; retry
6| 1W ; expire
7| 1D ) ; minimum seconds
8| IN NS strider.diverge.org.
9|1 IN PTR strider.diverge.org.
10|2 IN PTR samwise.diverge.org.
11|3 IN PTR worm.diverge.org.
28.2.6.etc/namedb/root.cache
This file contains a list of root name servers for your server to query when it
gets requests outside of its own domain that it cannot answer itself. Here are
first few lines of a root zone file:
;
; This file holds the information on root name servers needed to
; initialize cache of Internet domain name servers
; (e.g. reference this file in the "cache . <file>"
; configuration file of BIND domain name servers).
;
; This file is made available by InterNIC
; under anonymous FTP as
; file /domain/db.cache
; on server FTP.INTERNIC.NET
; -OR- RS.INTERNIC.NET
;
; last update: Jan 29, 2004
; related version of root zone: 2004012900
;
;
; formerly NS.INTERNIC.NET
;
. 3600000 IN NS A.ROOT-SERVERS.NET.
A.ROOT-SERVERS.NET. 3600000 A 198.41.0.4
;
; formerly NS1.ISI.EDU
;
. 3600000 NS B.ROOT-SERVERS.NET.
B.ROOT-SERVERS.NET. 3600000 A 192.228.79.201
;
; formerly C.PSI.NET
;
. 3600000 NS C.ROOT-SERVERS.NET.
C.ROOT-SERVERS.NET. 3600000 A 192.33.4.12
;
...
This file can be obtained from ISC at http://www.isc.org/ and usually comes
with a distribution of BIND. A root.cache file is included in the NetBSD
operating system's "etc" set.
This section has described the most important files and settings for a DNS
server. Please see the BIND documentation in /usr/src/dist/bind/doc/bog and
named.conf(5) for more information.
28.3. Õsing DNS
In this section we will look at how to get DNS going and setup "strider" to use
its own DNS services.
Setting up named to start automatically is quite simple. In /etc/rc.conf simply
set named=yes. Additional options can be specified in named_flags, for example,
I like to use -g nogroup -u nobody, so a non-root account runs the "named"
process.
In addition to being able to startup "named" at boot time, it can also be
controlled with the ndc command. In a nutshell the ndc command can stop, start
or restart the named server process. It can also do a great many other things.
Before use, it has to be setup to communicate with the "named" process, see the
ndc(8) and named.conf(5) man pages for more details on setting up communication
channels between "ndc" and the "named" process.
Next we want to point "strider" to itself for lookups. We have two simple
steps, first, decide on our resolution order. On a network this small, it is
likely that each host has a copy of the hosts table, so we can get away with
using /etc/hosts first, and then DNS. However, on larger networks it is much
easier to use DNS. Either way, the file where order of name services used for
resolution is determined is /etc/nsswitch.conf Here is part of a typical
nsswitch.conf:
. . .
group_compat: nis
hosts: files dns
netgroup: files [notfound=return] nis
. . .
The line we are interested in is the "hosts" line. "files" means the system
uses the /etc/hosts file first to determine ip to name translation, and if it
can't find an entry, it will try DNS.
The next file to look at is /etc/resolv.conf, which is used to configure DNS
lookups ("resolution") on the client side. The format is pretty self
explanatory but we will go over it anyway:
domain diverge.org
search diverge.org
nameserver 192.168.1.1
In a nutshell this file is telling the resolver that this machine belongs to
the "diverge.org" domain, which means that lookups that contain only a hostname
without a "." gets this domain appended to build a FQDN. If that lookup doesn't
succeed, the domains in the "search" line are tried next. Finally, the
"nameserver" line gives the IP addresses of one or more DNS servers that should
be used to resolve DNS queries.
To test our nameserver we can use several commands, for example:
# host sam
sam.diverge.org has address 192.168.1.2
As can be seen, the domain was appended automatically here, using the value
from /etc/resolv.conf. Here is another example, the output of running host
www.yahoo.com:
$ host www.yahoo.com
www.yahoo.com is an alias for www.yahoo.akadns.net.
www.yahoo.akadns.net has address 68.142.226.38
www.yahoo.akadns.net has address 68.142.226.39
www.yahoo.akadns.net has address 68.142.226.46
www.yahoo.akadns.net has address 68.142.226.50
www.yahoo.akadns.net has address 68.142.226.51
www.yahoo.akadns.net has address 68.142.226.54
www.yahoo.akadns.net has address 68.142.226.55
www.yahoo.akadns.net has address 68.142.226.32
Other commands for debugging DNS besides host(1) are nslookup(8) and dig(1).
Note that ping(8) is not useful for debugging DNS, as it will use whatever is
configured in /etc/nsswitch.conf to do the name-lookup.
At this point the server is configured properly. The procedure for setting up
the client hosts are easier, you only need to setup /etc/nsswitch.conf and /etc
/resolv.conf to the same values as on the server.
28.4. Óetting up a caching only name server
A caching only name server has no local zones; all the queries it receives are
forwarded to the root servers and the replies are accumulated in the local
cache. The next time the query is performed the answer will be faster because
the data is already in the server's cache. Since this type of server doesn't
handle local zones, to resolve the names of the local hosts it will still be
necessary to use the already known /etc/hosts file.
Since NetBSD supplies defaults for all the files needed by a caching only
server, it only needs to be enabled and started and is immediately ready for
use! To enable named, put named=yes into /etc/rc.conf, and tell the system to
use it adding the following line to the /etc/resolv.conf file:
# cat /etc/resolv.conf
nameserver 127.0.0.1
Now we can start named:
# sh /etc/rc.d/named restart
28.4.1. Ôesting the server
Now that the server is running we can test it using the nslookup(8) program:
$ nslookup
Default server: localhost
Address: 127.0.0.1
>
Let's try to resolve a host name, for example "www.NetBSD.org":
> www.NetBSD.org
Server: localhost
Address: 127.0.0.1
Name: www.NetBSD.org
Address: 204.152.190.12
If you repeat the query a second time, the result is slightly different:
> www.NetBSD.org
Server: localhost
Address: 127.0.0.1
Non-authoritative answer:
Name: www.NetBSD.org
Address: 204.152.190.12
As you've probably noticed, the address is the same, but the message "
Non-authoritative answer" has appeared. This message indicates that the answer
is not coming from an authoritative server for the domain NetBSD.org but from
the cache of our own server.
The results of this first test confirm that the server is working correctly.
We can also try the host(1) and dig(1) commands, which give the following
result.
$ host www.NetBSD.org
www.NetBSD.org has address 204.152.190.12
$
$ dig www.NetBSD.org
; <<>> DiG 8.3 <<>> www.NetBSD.org
;; res options: init recurs defnam dnsrch
;; got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19409
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 5, ADDITIONAL: 0
;; QUERY SECTION:
;; www.NetBSD.org, type = A, class = IN
;; ANSWER SECTION:
www.NetBSD.org. 23h32m54s IN A 204.152.190.12
;; AUTHORITY SECTION:
NetBSD.org. 23h32m54s IN NS uucp-gw-1.pa.dec.com.
NetBSD.org. 23h32m54s IN NS uucp-gw-2.pa.dec.com.
NetBSD.org. 23h32m54s IN NS ns.NetBSD.org.
NetBSD.org. 23h32m54s IN NS adns1.berkeley.edu.
NetBSD.org. 23h32m54s IN NS adns2.berkeley.edu.
;; Total query time: 14 msec
;; FROM: miyu to SERVER: 127.0.0.1
;; WHEN: Thu Nov 25 22:59:36 2004
;; MSG SIZE sent: 32 rcvd: 175
As you can see dig(1) gives quite a bit of output, the expected answer can be
found in the "ANSWER SECTION". The other data given may be of interest when
debugging DNS problems.
Chapter9. Íail and news
Table of Contents
29.1. postfix
29.1.1. Configuration of generic mapping
29.1.2. Testing the configuration
29.1.3. Using an alternative MTA
29.2. fetchmail
29.3. Reading and writing mail with mutt
29.4. Strategy for receiving mail
29.5. Strategy for sending mail
29.6. Advanced mail tools
29.7. News with tin
This chapter explains how to set up NetBSD to use mail and news. Only a simple
but very common setup is described: the configuration of a host connected to
the Internet with a modem through a provider. You can think of this chapter as
the continuation of Chapter6, Setting up TCP/IP on NetBSD in practice,
assuming a similar network configuration. Even this "simple" setup proves to be
difficult if you don't know where to start or if you've only read introductory
or technical documentation. A general description of mail and news
configuration is beyond the scope of this guide; please read a good Unix
Administration book (some very good ones are listed on the NetBSD site).
This chapter also briefly describes the configuration (but not the usage) of
two popular applications, mutt for mail and tin for news. The usage is not
described because they are easy to use and well documented. Obviously, both
mutt and tin are not mandatory choices: many other similar applications exist
but I think that they are a good starting point because they are widely used,
simple, work well and don't use too much disk space and memory. Both are
console mode programs; if you prefer graphics applications there are also many
choices for X.
In short, the programs required for the configuration described in this chapter
are:
* postfix
* fetchmail
* mutt
* tin
Only postfix is installed with the base system; you can install the other
programs from the NetBSD package collection, pkgsrc.
Note
Because sendmail is widely popular and several programs like fetchmail are
designed to be used with it, postfix includes a command line wrapper that
accepts sendmail's commands line syntax but works with postfix. See sendmail(1)
for more details.
Before continuing, remember that none of the programs presented in this chapter
is mandatory: there are other applications performing similar tasks and many
users prefer them. You'll find different opinions reading the mailing lists.
You can also use different strategies for sending and receiving mail: the one
explained here is only a starting point; once you understand how it works
you'll probably want to modify it to suit your needs or to adopt a different
method altogether.
At the opposite extreme of the example presented here, there is the usage of an
application like Mozilla, which does everything and frees you from the need of
configuring many components: with Mozilla you can browse the Internet, send and
receive mail and read news. Besides, the setup is very simple. There is a price
to pay, though: Mozilla is a "closed" program that will not cooperate easily
with other standard Unix utilities.
Another possibility is to use emacs to read mail and news. Emacs needs no
introduction to Unix users but, in case you don't know, it is an extensible
editor (although calling emacs an editor is somewhat reductive) which becomes a
complete work environment, and can be used to read mail, news and to perform
many operations. For many people emacs is the only environment that they need
and they use it for all their work. The configuration of emacs for mail and
news is described in the emacs manual.
In the rest of this chapter we will deal with a host connected to the Internet
through a PPP connection via serial modem to a provider.
* the local host's name is "ape" and the internal network is "insetti.net",
which means that the FQDN (Fully Qualified Domain Name) is "ape.insetti.net
".
* the user's login name on ape is "carlo".
* the provider's name is BigNet.
* the provider's mail server is "mail.bignet.it".
* the provider's news server is "news.bignet.it".
* the user's ("carlo") account at the provider is "alan" with the password "
pZY9o".
First some basic terminology:
MUA (mail user agent)
a program to read and write mail. For example: mutt, elm and pine but also
the simple mail application installed with the base system.
MTA (mail transfer agent)
a program that transfers mail between two host but also locally (on the
same host). The MTA decides the path that the mail will follow to get to
the destination. On other BSD systems (but not only) the standard MTA is
sendmail, other examples are qmail, exim and Microsoft Exchange.
MDA (mail delivery agent)
a program, usually used by the MTA, that delivers the mail; for example, it
physically puts the messages in the recipient's mailbox. For example,
postfix uses one or more MDAs to deliver mail, and procmail is another
well-known MDA.
Figure9.1, "Structure of the mail system" depicts the mail system that we
want to set up. Between the local network (or the single host) and the provider
there is a modem PPP connection. The "bubbles" with the thick border (postfix,
fetchmail, mutt) are the programs launched manually by the user; the remaining
bubbles are the programs that are launched automatically. The circled numbers
refer to the logical steps of the mail cycle:
1. In step (1) mail is downloaded from the provider's POP server using
fetchmail, which hands messages off to postfix's sendmail wrapper to put
the messages in the user's mailbox.
2. In step (2) the user launches mutt (or another MUA) to read mail, reply and
write new messages.
3. In step (3) the user "sends" the mail from within mutt. Messages are
accumulated in the spool area.
4. In step (4) the user calls postfix's sendmail wrapper to transfer the
messages to the provider's SMTP server, that will deliver them to the final
destination (possibly through other mail servers). The provider's SMTP
server acts as a relay for our mail.
The connection with the provider must be up only during steps (1) and (4); for
the remaining steps it is not needed.
Figure9.1. Ótructure of the mail system
Structure of the mail system
29.1. ðostfix
When an MTA must deliver a local message, it is delivered directly. If the
message is intended for a different domain, the MTA must find out the address
of the mail server for that domain. Postfix uses the DNS service (described in
Chapter8, The Domain Name System) to find a mail exchanger handling mail for
the given domain, and delivers the message to that mail server then.
Postfix is controlled by a set of configuration files and databases, of which /
etc/postfix/main.cf and /etc/postfix/master.cf are the most important.
The first problem to be solved is that the local network we are dealing with is
an internal network, i.e. not directly accessible from the Internet. This means
that the names used internally have no meaning on the Internet; in short, "
ape.insetti.net" cannot be reached by an external host: no one will be able to
reply to a mail sent with this return address (many mail systems will even
reject the message as spam prevention as it comes from an unknown host). The
true address, the one visible from everybody, is assigned by the provider and,
therefore, it is necessary to convert the local address "carlo@ape.insetti.net"
to the real address "alan@bignet.it". Postfix, if correctly configured, will
take care of this when it transfers the messages.
You'll probably also want to configure postfix in order to send the e-mails to
the provider's mail server, using it as a relay. In the configuration described
in this chapter, postfix does not directly contact the recipient's mail server
(as previously described) but relays all its mail to the provider's mail
server.
Note
The provider's mail server acts as a relay, which means that it delivers mail
which is not destined to its own domain, to another mail server. It acts as an
intermediary between two servers.
Since the connection with the provider is not always active, it is not
necessary to start postfix as a daemon in /etc/rc.conf: you can disable it with
the line "postfix=NO". As a consequence it will be necessary to launch postfix
manually when you want to transfer mail to the provider. Local mail is
delivered correctly even if postfix is not active as a daemon.
Let's start configuring postfix.
29.1.1. Ãonfiguration of generic mapping
This type of configuration uses a new file /etc/postfix/generic which contains
the hostname mapping used by postfix to rewrite the internal hostnames.
The first step is therefore to write the mapping file:
carlo@ape.insetti.net alan@bignet.it
root@ape.insetti.net alan@bignet.it
news@ape.insetti.net alan@bignet.it
These entries will map the mail sent from the users given on the left side into
the globally valid email addresses given on the right, making it appear as if
the mail was really sent from that address.
For the sake of efficiency, generic must be transformed into a binary file with
the following command:
# postmap /etc/postfix/generic
Now it's time to create the prototype configuration file which we'll use to
create the postfix configuration file.
# vi /etc/postfix/main.cf
For the sake of simplicity, we'll only show the variables you need to change:
relayhost = mail.bignet.it
smtp_generic_maps = hash:/etc/postfix/generic
This configuration tells postfix to rewrite the addresses of type "
ape.insetti.net" using the real names found in the /etc/postfix/generic file.
It also says that mail should be sent to the "mail.bignet.it" server. The
meaning of the options is described in detail in postconf(5).
The last step is to reload the configuration. You can do that easily with:
# /etc/rc.d/postfix reload
postfix/postfix-script: refreshing the Postfix mail system
Now everything is ready to start sending mail.
29.1.2. Ôesting the configuration
Postfix is finally configured and ready to work, but before sending real mail
it is better to do some simple tests. First let's try sending a local e-mail
with the following command (postfix's sendmail wrapper):
$ sendmail carlo
Subject: test
Hello world
.
Please follow exactly the example above: leave a blank line after Subject: and
end the message with a line containing only one dot. Now you should be able to
read the message with your mail client and verify that the From: field has been
correctly rewritten.
From: alan@bignet.it
29.1.3. Õsing an alternative MTA
$ ls -l /usr/sbin/sendmail
lrwxr-xr-x 1 root wheel 21 Nov 1 01:14 /usr/sbin/sendmail@ -> /usr/sbin/mailwrapper
The purpose of mailwrapper is to allow the usage of an alternative MTA instead
of postfix (for example, sendmail). If you plan to use a different mailer I
suggest that you read the mailwrapper(8) and the mailer.conf(5) manpages, which
are very clear.
29.2. æetchmail
If someone sends me mail, it is received and stored by the provider, and not
automatically transferred to the local hosts; therefore it is necessary to
download it. Fetchmail is a very popular program that downloads mail from a
remote mail server (using e.g. the Post Office Protocol, POP) and forwards it
to the local system for delivery (usually using postfix's sendmail wrapper). It
is powerful yet easy to use and configure: after installation, the file ~
/.fetchmailrc must be created and the program is ready to run (~/.fetchmailrc
contains a password so appropriate permissions on the file are required).
This is an example .fetchmailrc:
poll mail.bignet.it
protocol POP3
username alan there with password pZY9o is carlo here
flush
mda "/usr/sbin/sendmail -oem %T"
The last line ("mda ...") is used only if postfix is not active as daemon on
the system. Please note that the POP-mail server indicated in this file
(mail.bignet.it) is only used to retrieve mails, and that it is not necessary
the same as the mail relay used by postfix to send out mails.
After setting up the .fetchmailrc file, the following command can be used to
download and deliver mail to the local system:
$ fetchmail
The messages can now be read with mutt.
29.3. Òeading and writing mail with mutt
Mutt is one of the most popular mail programs: it is "lightweight", easy to use
and has lots of features. The man page mutt is very bare bones; the real
documentation is in /usr/pkg/share/doc/mutt/, in particular manual.txt.
Mutt's configuration is defined by the ~/.muttrc file. The easiest way to
create it is to copy mutt's example muttrc file (usually /usr/pkg/share/
examples/mutt/sample.muttrc) to the home directory and modify it. The following
example shows how to achieve some results:
* Save a copy of sent mail.
* Define a directory and two files for incoming and outgoing mail saved by
mutt (in this example the directory is ~/Mail and the files are incoming
and outgoing).
* Define some colors.
* Define an alias.
set copy=yes
set edit_headers
set folder="~/Mail"
unset force_name
set mbox="~/Mail/incoming"
set record="~/Mail/outgoing"
unset save_name
bind pager <up> previous-page
bind pager <down> next-page
color normal white black
color hdrdefault blue black
color indicator white blue
color markers red black
color quoted cyan black
color status white blue
color error red white
color underline yellow black
mono quoted standout
mono hdrdefault underline
mono indicator underline
mono status bold
alias pippo Pippo Verdi <pippo.verdi@pluto.net>
To start mutt:
$ mutt
Please note that mutt supports color, but this depends on the terminal
settings. Under X you can use "xterm-color", for example:
$ env TERM=xterm-color mutt
29.4. Ótrategy for receiving mail
This section describes a simple method for receiving and reading mail. The
connection to the provider is activated only for the time required to download
the messages; mail is then read offline.
1. Activate the connection to the provider.
2. Run fetchmail.
3. Deactivate the connection.
4. Read mail with mutt.
29.5. Ótrategy for sending mail
When mail has been written and "sent" with mutt, the messages must be
transferred to the provider with postfix. Mail is sent from mutt with the y
command, but this does not really send it; the messages are enqueued in the
spool area; if postfix is not active as a daemon it is necessary to start it
manually or the messages will remain on the hard disk. The necessary steps are:
1. Write mail with mutt, send it and exit mutt. You can check if and what
messages are in the postfix mail queue using the mailq(1) program.
2. Activate the connection with the provider.
3. If your provider requires you to do "SMTP-after-POP", i.e. it first wants
to make sure to know who you are before you are allowed to send mail (and
no spam), you need to run fetchmail again first.
4. Write the command /usr/sbin/postfix flush to transfer the queued messages
to the provider.
5. Deactivate the connection when the queue is empty.
29.6. Ádvanced mail tools
When you start using mail, you won't probably have very sophisticated
requirements and the already described standard configuration will satisfy all
your needs. But for many users the number of daily messages will increase with
time and a more rational organization of the mail storage will become
necessary, for example subdividing mail in different mail boxes organized by
topic. If, for example, you subscribe to a mailing list, you will likely
receive many messages every day and you will want to keep them separate from
the rest of your mail. You will soon find that you are spending too much time
every day repeating the same manual operations to organize your mail boxes.
Why repeat the same operations manually when you can have a program perform
them automatically for you? There are numerous tools that you can add to your
mail system to increase its flexibility and automatically process your
messages. Amongst the most known and used there are:
* procmail, an advanced mail delivery agent and general purpose mail filter
for local mail, which automatically processes incoming mail using user
defined rulesets. It integrates smoothly with sendmail/postfix.
* spamassassin or spamprobe, to help fight spam.
* metamail, a tool to process attachments.
* formail, a mail formatter.
In the remaining part of this section a sample configuration for procmail will
be presented for a very common case: delivering automatically to a user defined
mailbox all the messages coming from a mailing list. The configuration of
postfix will be modified in order to call procmail directly (procmail will be
the local mailer used by sendmail). and a custom configuration file for
procmail will be created.
First, procmail must be installed using the package system (mail/procmail) or
pkg_add.
Next, the configuration of postfix must be changed, in order to use procmail as
local mailer:
mailbox_command = /usr/pkg/bin/procmail
The line defines the path of the procmail program (you can see where procmail
is installed with the command which procmail).
The last step is the creation of the procmail configuration file, containing
the recipes for mail delivery.
Let's say that, for example, you subscribed to a mailing list on roses whose
address is "roses@flowers.org" and that every message from the list contains
the following line in the header:
Delivered-To: roses@flowers.org
Assuming you want to automatically sort all mails going over that list into the
local mail folder "roses_list", the procmail configuration file (.procmailrc)
looks like this:
PATH=/bin:/usr/bin:/usr/pkg/bin
MAILDIR=$HOME/Mail
LOGFILE=$MAILDIR/from
:0
* ^Delivered-To: roses@flowers.org
roses_list
The previous file contains only one rule, beginning with the line containing "
:0". The following line identifies all messages containing the string "
Delivered-To: roses@flowers.org" and the last line says that the selected
messages must go to the roses_list mailbox (which you should have created in
$MAILDIR). The remaining messages will be delivered to the default mailbox.
Note that $MAILDIR is the same directory that you have configured with mutt:
set folder="~/Mail"
Of course the mailing list is only an example; procmail is a very versatile
tool which can be used to filter mail based on many criteria. As usual, refer
to the man pages for more details: procmail(1), procmailrc(5), and procmailex
(5) (this last one contains many examples of configuration files).
29.7. Îews with tin
The word news indicates the set of messages posted to the USENET newsgroups, a
service available on the Internet. Each newsgroup contains articles related to
a specific topic. Reading a newsgroup is different than reading a mailing list:
when you subscribe to a mailing list you receive the articles by mail and you
read them with a standard mail program like mutt, which you use also to send
replies. News, instead, are read directly from a news server with a dedicated
program called newsreader like, for example, tin. With tin you can subscribe to
the newsgroups that you're interested in and follow the threads. A thread is a
sequence of articles which all derive from an article that we could call "
original". In short, a message is sent to the group, someone answers, other
people answer to those who answered in the first place and so on, creating a
tree like structure of messages and replies: without a newsreader it is
impossible to understand the correct sequence of messages.
After the installation of tin (from the package collection as usual) the only
thing left to do is to write the name of the NNTP server in the file /usr/pkg/
etc/nntp/server, which you may need to create first. For example:
news.bignet.it
Once this has been done, the program can be started with the command tin. On
the screen something similar to the following example will be displayed:
$ tin
Connecting to news.bignet.it...
news.bignet.it InterNetNews NNRP server INN 1.7.2 08-Dec-1997 ready (posting ok).
Reading groups from active file...
Checking for new groups...
Reading attributes file...
Reading newsgroups file...
Creating newsrc file...
Autosubscribing groups...
Reading newsrc file...
Be patient when you connect for the first time, because tin downloads an
immense list of newsgroups to which you can subscribe and this takes several
minutes. When the download is finished, the program's main screen is displayed;
usually no groups are displayed; to see the list of groups press y. To
subscribe to a group, move on the group's name and press y.
Once that you have subscribed to some newsgroups you can start tin more quickly
with the command tin -Q. The search for new groups is disabled (-q), only
active groups are searched (-n) and newsgroup description are not loaded (-d):
it will not be possible to use the y (yank) command in tin. When tin is started
with this option it can't tell if a newsgroup is moderated or not.
Note that if you are connecting from an internal network (like in our example),
when you send ("post") a message the address at the beginning of the message
will be wrong (because it is the internal address). To solve the problem, use
the option "mail_address" in the tin configuration file (~/.tin/tinrc) or set
the REPLYTO environment variable.
Chapter0. Éntroduction to the Common Address Redundancy Protocol (CARP)
Table of Contents
30.1. CARP Operation
30.2. Configuring CARP
30.3. Enabling CARP Support
30.4. CARP Example
30.5. Advanced CARP configuration
30.6. Forcing Failover of the Master
See Section Ä.3.3, "Joel Knight's license on the CARP article" for the license
of this chapter.
CARP is the Common Address Redundancy Protocol. Its primary purpose is to allow
multiple hosts on the same network segment to share an IP address. CARP is a
secure, free alternative to the Virtual Router Redundancy Protocol and the Hot
Standby Router Protocol.
CARP works by allowing a group of hosts on the same network segment to share an
IP address. This group of hosts is referred to as a "redundancy group". The
redundancy group is assigned an IP address that is shared amongst the group
members. Within the group, one host is designated the "master" and the rest as
"backups". The master host is the one that currently "holds" the shared IP; it
responds to any traffic or ARP requests directed towards it. Each host may
belong to more than one redundancy group at a time.
One common use for CARP is to create a group of redundant firewalls. The
virtual IP that is assigned to the redundancy group is configured on client
machines as the default gateway. In the event that the master firewall suffers
a failure or is taken offline, the IP will move to one of the backup firewalls
and service will continue unaffected.
While highly redundant and fault-tolerant hardware minimizes the need for CARP,
it doesn't erase it. There's no hardware fault tolerance that's capable of
helping if someone knocks out a power cord, or if your system administrator
types reboot in the wrong window. CARP also makes it easier to make the patch
and reboot cycle transparent to users, and easier to test a software or
hardware upgrade--if it doesn't work, you can fall back to your spare until
fixed.
There are, however, situations in which CARP won't help. CARP's design does
require that the members of a group be on the same physical subnet with a
static IP address, although with the introduction of the carpdev directive,
there is no more need for IP addresses on the physical interfaces. Similarly,
services that require a constant connection to the server (such as SSH or IRC)
will not be transparently transferred to the other system--though in this case,
CARP can help with minimizing downtime. CARP by itself does not synchronize
data between applications, for example, manually duplicating data between boxes
with rsync, or whatever is appropriate for your application.
CARP supports both IPv4 and IPv6.
30.1. ÃARP Operation
The master host in the group sends regular advertisements to the local network
so that the backup hosts know it's still alive. If the backup hosts don't hear
an advertisement from the master for a set period of time, then one of them
will take over the duties of master (whichever backup host has the lowest
configured advbase and advskew values). It's possible for multiple CARP groups
to exist on the same network segment. CARP advertisements contain the Virtual
Host ID which allows group members to identify which redundancy group the
advertisement belongs to.
In order to prevent a malicious user on the network segment from spoofing CARP
advertisements, each group can be configured with a password. Each CARP packet
sent to the group is then protected by an SHA1 HMAC.
30.2. Ãonfiguring CARP
Each redundancy group is represented by a carp(4) virtual network interface. As
such, CARP is configured using ifconfig(8) The follow options are available:
carpN
The name of the carp(4) virtual interface where N is a integer that
represents the interface's number (e.g. carp0).
vhid
The Virtual Host ID. This is a unique number that is used to identify the
redundancy group to other nodes on the network. Acceptable values are from
1 to 255. This allows for multiple redundancy groups to exist on the same
network.
password
The authentication password to use when talking to other CARP-enabled hosts
in this redundancy group. This must be the same on all members of the
redundancy group.
carpdev
This optional parameter specifies the physical network interface that
belongs to this redundancy group. By default, CARP will try to determine
which interface to use by looking for a physical interface that is in the
same subnet as the ipaddress and mask combination given to the carp(4)
interface.
advbase
This optional parameter specifies how often, in seconds, to advertise that
we're a member of the redundancy group. The default is 1 second. Acceptable
values are from 1 to 255.
advskew
This optional parameter specifies how much to skew the advbase when sending
CARP advertisements. By manipulating advbase, the master CARP host can be
chosen. The higher the number, the less preferred the host will be when
choosing a master. The default is 0. Acceptable values are from 1 to 254.
state
Force a carp(4) interface into a certain state. Valid states are init,
backup, and master
ipaddress
This is the shared IP address assigned to the redundancy group. This
address does not have to be in the same subnet as the IP address on the
physical interface (if present). This address needs to be the same on all
hosts in the group, however.
mask
The subnet mask of the shared IP.
Further CARP behaviour can be controlled via sysctl(8)
net.inet.carp.allow
Accept incoming CARP packets or not. Default is 1 (yes).
net.inet.carp.preempt
Allow hosts within a redundancy group that have a better advbase and
advskew to preempt the master. In addition, this option also enables
failing over all interfaces in the event that one interface goes down. If
one physical CARP-enabled interface goes down, CARP will change advskew to
240 on all other CARP-enabled interfaces, in essence, failing itself over.
This option is 0 (disabled) by default.
net.inet.carp.log
Log bad CARP packets. Default is 0 (disabled).
net.inet.carp.arpbalance
Load balance traffic across multiple redundancy group hosts. Default is 0
(disabled). See carp(4) for more information.
30.3. Ånabling CARP Support
CARP support is not enabled by default.
To use carp(4) you need a kernel with support for the carp pseudo-device. Make
sure the following line is in your kernel configuration file:
pseudo-device carp # CARP
After configuring the carp pseudo-device in your kernel configuration, you must
recompile your kernel and reboot to enable carp(4) support.
30.4. ÃARP Example
An example CARP configuration:
# sysctl -w net.inet.carp.allow=1
# ifconfig carp0 create
# ifconfig carp0 vhid 1 pass lanpasswd \
carpdev em0 advskew 100 10.0.0.1 255.255.255.0
This sets up the following:
* Enables receipt of CARP packets (this is the default setting)
* Creates a carp(4) interface.
* Configures carp0 for virtual host #1, enables a password(lanpasswd), sets
em0 as the interface belonging to the group, and makes this host a backup
due to the advskew of 100 (assuming of course that the master is set up
with an advskew less than 100). The shared IP assigned to this group is
10.0.0.1/255.255.255.0.
Running ifconfig on carp0 shows the status of the interface:
# ifconfig carp0
carp0: flags=8802<UP,BROADCAST,SIMPLEX,MULTICAST> mtu 1500
carp: BACKUP carpdev em0 vhid 1 advbase 1 advskew 100
inet 10.0.0.1 netmask 0xffffff00 broadcast 10.0.0.255
30.5. Ádvanced CARP configuration
The following example creates a cluster of two highly-available, redundant
firewalls. The following diagram presents what we're trying to achieve:
+----| WAN/Internet |----+
| |
em1| |em1
+-----+ +-----+
| fw1 | | fw2 |
+-----+ +-----+
em0| |em0
| |
---+-------Shared LAN-------+---
Both firewalls are connected to the LAN on em0 and to a WAN/Internet connection
on em1. IP addresses are as follows:
* Firewall 1 (fw1) em0: 172.16.0.1
* Firewall 1 (fw1) em1: 192.0.2.1
* Firewall 2 (fw2) em0: 172.16.0.2
* Firewall 2 (fw2) em1: 192.0.2.2
The IP addresses we wish to share between the redundancy groups:
* WAN/Internet Shared IP: 192.0.2.100
* LAN Shared IP: 172.16.0.100
The network policy is that Firewall 1 (fw1) will be the preferred master.
The following configuration is for Firewall 1 (fw1):
#Enable preemption and group interface failover
# sysctl -w net.inet.carp.preempt=1
#Configure CARP on the LAN side
# ifconfig carp0 create
# ifconfig carp0 vhid 1 pass lanpasswd carpdev em0 \
172.16.0.100 255.255.255.0
#Configure CARP on the WAN side
# ifconfig carp1 create
# ifconfig carp1 vhid 2 pass wanpasswd carpdev em1 \
192.0.2.100 255.255.255.0
As mentioned before, our policy is for Firewall 1 to be the preferred master.
When configuring Firewall 2 we make the advskew a higher value since it's less
preferred to be the master.
The following configuration is for Firewall 2 (fw2):
#Enable preemption and group interface failover
# sysctl -w net.inet.carp.preempt=1
#Configure CARP on the LAN side
# ifconfig carp0 create
# ifconfig carp0 vhid 1 pass lanpasswd carpdev em0 \
advskew 128 172.16.0.100 255.255.255.0
#Configure CARP on the WAN side
# ifconfig carp1 create
# ifconfig carp1 vhid 2 pass wanpasswd carpdev em1 \
advskew 128 192.0.2.100 255.255.255.0
30.6. Æorcing Failover of the Master
There can be times when it's necessary to failover or demote the master node on
purpose. Examples include taking the master node down for maintenance or when
troubleshooting a problem. The objective here is to gracefully fail over
traffic to one of the backup hosts so that users do not notice any impact.
To failover, shut down the carp(4) interface on the master node. This will
cause the master to advertise itself with an "infinite" advbase and advskew.
The backup host(s) will see this and immediately take over the role of master.
# ifconfig carp0 down
Chapter1. Îetwork services
Table of Contents
31.1. The Network File System (NFS)
31.1.1. NFS setup example
31.1.2. Setting up NFS automounting for /net with amd(8)
31.2. The Network Time Protocol (NTP)
31.1. Ôhe Network File System (NFS)
Now that the network is working it is possible to share files and directories
over the network using the Network File System (NFS). From the point of view of
file sharing, the computer which gives access to its files and directories is
called the server, and the computer using these files and directories is the
client. A computer can be client and server at the same time.
* The server must enable the rpcbind, mountd lockd statd and nfs_server
daemons in /etc/rc.conf:
rpcbind=yes
mountd=yes
nfs_server=yes
lockd=yes
statd=yes
* The client must enable the rpcbind, lockd statd and nfs_client daemons in /
etc/rc.conf:
rpcbind=yes
nfs_client=yes
lockd=yes
statd=yes
* The server must list the exported directories in /etc/exports and then run
the command kill -HUP `cat /var/run/mountd.pid (hup mountd may work too!).
A client host can access a remote directory through NFS if:
* The server host exports the directory to the client. The list of
filesystems a NFS server exports can be checked with the showmount -e
command, see showmount(8):
# showmount -e 192.168.1.2
Exports list on 192.168.1.2:
/home host1 host2 host3
* The client host mounts the remote directory with the command mount
192.168.1.2:/home /home
The mount command has a rich set of options for remote directories which are
not very intuitive (to say the least).
31.1.1. ÎFS setup example
The scenario described here is the following: five client machines (cli1, ...,
cli5) share some directories on a server (buzz.toys.org). Some of the
directories exported by the server are reserved for a specific client, the
other directories are common for all client machines. All the clients boot from
the server and must mount the directories.
The directories exported from the server are:
/export/cli?/root
the five root directories for the five client machines. Each client has its
own root directory.
/export/cli?/swap
Five swap directories for the five swap machines.
/export/common/usr
/usr directory; common for all client hosts.
/usr/src
Common /usr/src directory for all client machines.
The following file systems exist on the server
/dev/ra0a on /
/dev/ra0f on /usr
/dev/ra1a on /usr/src
/dev/ra2a on /export
Each client needs the following file systems
buzz:/export/cli?/root on /
buzz:/export/common/usr on /usr
buzz:/usr/src on /usr/src
The server configuration is the following:
# /etc/exports
/usr/src -network 192.168.1.0 -mask 255.255.255.0
/export -alldirs -maproot=root -network 192.168.1.0 -mask 255.255.255.0
On the client machines /etc/fstab contains:
buzz:/export/cliX/root / nfs rw
buzz:/export/common/usr /usr nfs ro,nodev,nosuid
buzz:/usr/src /usr/src nfs rw,nodev,nosuid
Each client machine has its number substituted to the "X" character in the
first line of the previous example.
31.1.2. Óetting up NFS automounting for /net with amd(8)
31.1.2.1. Éntroduction
The problem with NFS (and other) mounts is, that you usually have to be root to
make them, which can be rather inconvenient for users. Using amd(8) you can set
up a certain directory (Commonly /net), under which one can make any NFS-mount
as a normal user, as long as the filesystem about to be accessed is actually
exported by the NFS server.
To check if a certain server exports a filesystem, and which ones, use the
showmount-command with the -e (export) switch:
$ showmount -e wuarchive.wustl.edu
Exports list on wuarchive.wustl.edu:
/export/home onc.wustl.edu
/export/local onc.wustl.edu
/export/adm/log onc.wustl.edu
/usr onc.wustl.edu
/ onc.wustl.edu
/archive Everyone
If you then want to mount a directory to access anything below it (for example
/archive/systems/unix/NetBSD), just change into that directory:
$ cd /net/wuarchive.wustl.edu/archive/systems/unix/NetBSD
The filesystem will be mounted (by amd), and you can a access any files just as
if the directory was mounted by the superuser of your system.
31.1.2.2. Áctual setup
You can set up such a /net directory with the following steps (including basic
amd configuration):
1. in /etc/rc.conf, set the following variable:
amd=yes
2. mkdir /amd
3. mkdir /net
4. Taking /usr/share/examples/amd/amd.conf, put the following into /etc/
amd.conf:
[ /net ]
map_name = /etc/amd/net
map_type = file
5. Taking /usr/share/examples/amd/net as example, put the following into /etc/
amd/net:
/defaults type:=host;rhost:=${key};fs:=${autodir}/${rhost}/root
* host==${key};type:=link;fs:=/ \
host!=${key};opts:=ro,soft,intr,nodev,nosuid,noconn
6. Reboot, or (re)start amd by hand:
# sh /etc/rc.d/amd restart
31.2. Ôhe Network Time Protocol (NTP)
It is not unusual to find that the system clock is wrong, often by several
minutes: for some strange reason it seems that computer clocks are not very
accurate. The problem gets worse if you administer many networked hosts:
keeping the clocks in sync can easily become a nightmare. To solve this
problem, the NTP protocol (version 3) comes to our aid: this protocol can be
used to synchronize the clocks of a network of workstations using one or more
NTP servers.
Thanks to the NTP protocol it is possible to adjust the clock of a single
workstation but also to synchronize an entire network. The NTP protocol is
quite complex, defining a hierarchical master-slave structure of servers
divided in strata: the top of the hierarchy is occupied by stratum 1 servers,
connected to an external clock (ex. a radio clock) to guarantee a high level of
accuracy. Underneath, stratum 2 servers synchronize their clocks with stratum
1, and so on. The accuracy decreases as we proceed towards lower levels. This
hierarchical structure avoids the congestion which could be caused by having
all hosts refer to the same (few) stratum 1 servers. If, for example, you want
to synchronize a network, you don't connect all the hosts to the same public
stratum 1 server. Instead, you create a local server which connects to the main
server and the remaining hosts synchronize their clocks with the local server.
Fortunately, to use the NTP tools you don't need to understand the details of
the protocol and of its implementation (if you are interested, refer to RFC
1305) and you only need to know how to configure and start some programs. The
base system of NetBSD already contains the necessary tools to utilize this
protocol (and other time related protocols, as we'll see), derived from the
xntp implementation. This section describes a simple method to always have a
correct system time.
First, it is necessary to find the address of the public NTP servers to use as
a reference; a detailed listing can be found at http://support.ntp.org/bin/view
/Servers/WebHome. As an example, for Italy the three stratum 1 servers
tempo.cstv.to.cnr.it, ntp1.inrim.it, and ntp2.inrim.it can be used.
Next, to adjust the system clock give the following command as root:
# ntpdate -b ntp1.inrim.it ntp2.inrim.it
(substitute the names of the servers in the example with the ones that you are
actually using. Option -b tells ntpdate to set the system time with the
settimeofday system call, instead of slewing it with adjtime (the default).
This option is suggested when the difference between the local time and the
correct time can be considerable.
As you've seen, ntpdate is not difficult to use. The next step is to start it
automatically, in order to always have the correct system time. If you have a
permanent connection to the Internet, you can start the program at boot with
the following line of /etc/rc.conf:
ntpdate=YES ntpdate_hosts="ntp1.inrim.it"
The name of the NTP server to use is specified in the ntpdate_hosts variable;
if you leave this field empty, the boot script will try to extract the name
from the /etc/ntp.conf file.
If you don't have a permanent Internet connection (ex. you have a dial-up modem
connection through an ISP) you can start ntpdate from the ip-up script, as
explained in Chapter6, Setting up TCP/IP on NetBSD in practice. In this case
add the following line to the ip-up script:
/usr/sbin/ntpdate -s -b ntp1.inrim.it
(the path is mandatory or the script will probably not find the executable).
Option -s diverts logging output from the standard output (this is the default)
to the system syslog(3) facility, which means that the messages from ntpdate
will usually end up in /var/log/messages.
Besides ntpdate there are other useful NTP commands. It is also possible to
turn one of the local hosts into an NTP server for the remaining hosts of the
network. The local server will synchronize its clock with a public server. For
this type of configuration you must use the ntpd daemon and create the /etc/
ntp.conf configuration file. For example:
server ntp1.inrim.it
server ntp2.inrim.it
ntpd can be started too from rc.conf, using the relevant option:
ntpd=YES
NTP is not your only option if you want to synchronize your network: you can
also use the timed daemon or the rdate(8) command as well. timed was developed
for 4.3BSD.
Timed too uses a master-slave hierarchy: when started on a host, timed asks the
network time to a master and adjusts the local clock accordingly. A mixed
structure, using both timed and ntpd can be used. One of the local hosts gets
the correct time from a public NTP server and is the timed master for the
remaining hosts of network, which become its clients and synchronize their
clocks using timed. This means that the local server must run both NTP and
timed; care must be taken that they don't interfere with each other (timed must
be started with the -F hostname option so that it doesn't try to adjust the
local clock).
Finally, rdate(8) can be used to synchronize once against a given host, much
like ntpdate(8). The host in question must have the "time" service (port 37)
enabled in /etc/inetd.conf.
Part Ö. Âuilding the system
Table of Contents
32. Obtaining the sources
32.1. Preparing directories
32.2. Terminology
32.3. Downloading tarballs
32.3.1. Downloading sources for a NetBSD release
32.3.2. Downloading sources for a NetBSD stable branch
32.3.3. Downloading sources for a NetBSD-current development branch
32.4. Fetching by CVS
32.4.1. Fetching a NetBSD release
32.4.2. Fetching a NetBSD stable branch
32.4.3. Fetching the NetBSD-current development branch
32.4.4. Saving some cvs(1) options
33. Crosscompiling NetBSD with build.sh
33.1. Building the toolchain
33.2. Configuring the kernel manually
33.3. Building the kernel manually
33.4. Building the kernel with build.sh
33.5. Building the userland
33.6. Building the X Window System
33.7. Changing build behaviour
33.7.1. Changing the Destination Directory
33.7.2. Static Builds
33.7.3. Using build.sh options
33.7.4. make(1) variables used during build
34. Compiling the kernel
34.1. Requirements and procedure
34.2. Installing the kernel sources
34.3. Creating the kernel configuration file
34.4. Building the kernel manually
34.4.1. Configuring the kernel manually
34.4.2. Generating dependencies and recompiling manually
34.5. Building the kernel using build.sh
34.6. Installing the new kernel
34.7. If something went wrong
35. Updating an existing system from sources
35.1. Manual build and update procedure
35.1.1. Building a new userland
35.1.2. Building a new kernel
35.1.3. Installing the kernel and userland
35.1.4. Updating the system configuration files
35.1.5. Summary
35.2. Using sysinst
35.3. Using sysbuild and sysupgrade
35.3.1. Tweak: Building as non-root
35.3.2. Tweak: Setting up nightly builds
35.4. More details about the updating of configuration and startup files
35.4.1. Using etcupdate with source files
35.4.2. Using etcupdate with binary distribution sets
35.4.3. Using etcmanage instead of etcupdate
36. Building NetBSD installation media
36.1. Creating standard installation images with build.sh
36.2. Creating custom live disk images
Chapter2. Ïbtaining the sources
Table of Contents
32.1. Preparing directories
32.2. Terminology
32.3. Downloading tarballs
32.3.1. Downloading sources for a NetBSD release
32.3.2. Downloading sources for a NetBSD stable branch
32.3.3. Downloading sources for a NetBSD-current development branch
32.4. Fetching by CVS
32.4.1. Fetching a NetBSD release
32.4.2. Fetching a NetBSD stable branch
32.4.3. Fetching the NetBSD-current development branch
32.4.4. Saving some cvs(1) options
To read the NetBSD sources from your local disk or to build the system, you
need to download the NetBSD sources. This chapter explains a number of
different ways to obtain the NetBSD sources, although the preferred method is
to download the tarballs and then update via cvs(1).
32.1. Ðreparing directories
Traditionally, the NetBSD kernel and userland sources are placed in /usr/src.
This directory is not present by default in the NetBSD installation and you
will need to create it first. As it is in a system directory, you will need
root access to create the directory and make sure your normal user account can
write to it. For demonstration purposes, it is assumed that the non-root login
is carlo. Please replace it with a valid login name on your system:
$ su
Password: ********
# mkdir /usr/src
# chown <carlo> /usr/src
If you want the sources to the X Window System, you should prepare /usr/xsrc as
well:
# mkdir /usr/xsrc
# chown <carlo> /usr/xsrc
Note
Please note that for the subsequent steps, root access is neither needed nor
recommended, so this preparation step should be done first. All CVS operations
can (and should) be done as normal user, so relinquish your root privileges:
# exit
$
32.2. Ôerminology
Before starting to fetch or download the required files, you may want to know
the definitions of "Formal releases", "Maintenance branches" and other related
terms. That information is available under the NetBSD release glossary and
graphs.
32.3. Äownloading tarballs
It is sometimes faster to begin by downloading a source tarball. You can
download tarballs (see tar(1)) from ftp.NetBSD.org (or any other mirror) for a
number of releases or branches. These tarballs include the CVS directories, so
you can continue to update your source tree using cvs(1), as explained in the
CVS section.
Note that source tarballs for stable branches are only updated every three
days.
32.3.1. Äownloading sources for a NetBSD release
The source files to a release do not change after the release has been made.
The tarballs for the sources of a specific release are available under /pub/
NetBSD/NetBSD-<RELEASE-NUMBER>/source/sets/ on ftp.NetBSD.org (or a mirror),
where <RELEASE-NUMBER> is the release you want to fetch (for example, 9.1).
To fetch the sources of a NetBSD release using tarballs, simply do:
$ ftp -i ftp://ftp.NetBSD.org/pub/NetBSD/NetBSD-9.1/source/sets/
Trying 2001:470:a085:999::21:21 ...
Connected to ftp.NetBSD.org.
220 ftp.NetBSD.org FTP server (NetBSD-ftpd 20180428) ready.
331 Guest login ok, type your name as password.
[...]
250 CWD command successful.
ftp> mget *.tgz
local: gnusrc.tgz remote: gnusrc.tgz
229 Entering Extended Passive Mode (|||61968|)
150 Opening BINARY mode data connection for 'gnusrc.tgz' (152604808 bytes).
[...]
ftp> quit
221-
221 Thank you for using the FTP service on ftp.NetBSD.org.
You should now have 5 files:
$ ls *.tgz
gnusrc.tgz sharesrc.tgz src.tgz syssrc.tgz xsrc.tgz
You now must extract them all:
$ for file in *.tgz
> do
> tar -xzf $file -C /
> done
32.3.2. Äownloading sources for a NetBSD stable branch
$ ftp -i ftp://ftp.NetBSD.org/pub/NetBSD/NetBSD-release-9/tar_files/src/
Trying 2001:470:a085:999::21:21 ...
Connected to ftp.NetBSD.org.
220 ftp.NetBSD.org FTP server (NetBSD-ftpd 20180428) ready.
331 Guest login ok, type your name as password.
[...]
250 CWD command successful.
ftp> mget *.tar.gz
local: bin.tar.gz remote: bin.tar.gz
229 Entering Extended Passive Mode (|||56011|)
150 Opening BINARY mode data connection for 'bin.tar.gz' (996075 bytes).
[...]
ftp> quit
221-
Data traffic for this session was 429024351 bytes in 25 files.
Total traffic for this session was 429035139 bytes in 26 transfers.
221 Thank you for using the FTP service on ftp.NetBSD.org.
You should now have 25 files:
$ ls *.tar.gz
bin.tar.gz doc.tar.gz libexec.tar.gz tools.tar.gz
common.tar.gz etc.tar.gz regress.tar.gz top-level.tar.gz
compat.tar.gz external.tar.gz rescue.tar.gz usr.bin.tar.gz
config.tar.gz extsrc.tar.gz sbin.tar.gz usr.sbin.tar.gz
crypto.tar.gz games.tar.gz share.tar.gz
dist.tar.gz include.tar.gz sys.tar.gz
distrib.tar.gz lib.tar.gz tests.tar.gz
You now must extract them all:
$ for file in *.tar.gz
> do
> tar -xzf $file -C /usr
> done
32.3.3. Äownloading sources for a NetBSD-current development branch
To download the NetBSD-current tarballs, located under /pub/NetBSD/
NetBSD-current/tar_files/src, just follow the same steps as in Section2.3.2,
"Downloading sources for a NetBSD stable branch", but using this path.
You may also want to fetch the X Window System sources, available under: /pub/
NetBSD/NetBSD-current/tar_files/xsrc.
32.4. Æetching by CVS
CVS (Concurrent Versions System) can be used to fetch the NetBSD source tree or
to keep the NetBSD source tree up to date with respect to changes made to the
NetBSD sources. There are two main source modules available through cvs(1), "
src" and "xsrc".
The list of currently maintained branches is available under src/doc/BRANCHES
(see the "Status" entry on the "Release branches" section).
Caution!
Be sure to take care in selecting the correct and desired branch tag so you
don't accidentally downgrade your source tree.
Before you can do an initial (full) checkout of the NetBSD sources via
anonymous CVS, you must set the CVSROOT environment variable, which tells cvs
(1) where to fetch the files from:
$ export CVSROOT="anoncvs@anoncvs.NetBSD.org:/cvsroot"
Make sure that the environment variable CVS_RSH is set to "ssh".
$ export CVS_RSH="ssh"
In the examples below, we use the -P option, which tells CVS to prune empty
directories.
32.4.1. Æetching a NetBSD release
The source files to a release do not change after the release has been made.
To get the NetBSD (kernel and userland) sources for a specific release, run the
following command after setting CVSROOT as shown above:
$ cd /usr
$ cvs checkout -r <TAG> -P src
Where <TAG> is the release tag to be checked out, e.g., "netbsd-9-1-RELEASE".
If you want to fetch a later patchlevel, you would use, e.g., "
netbsd-9-1-RELEASE".
For example, in order to fetch the sources for NetBSD 9.1, you would use the "
netbsd-9-1-RELEASE" tag:
$ cvs checkout -r netbsd-9-1-RELEASE -P src
To fetch the X Window System source, just "checkout" the "xsrc" module. For
example:
$ cvs checkout -r netbsd-9-1-RELEASE -P xsrc
32.4.2. Æetching a NetBSD stable branch
NetBSD stable branches are a flavor of "Maintenance branches". Please consult
the Section2.2, "Terminology".
If you want to follow a stable branch, just pass the branch name to the cvs(1)
-r option.
For example, if you want to fetch the most recent version of "netbsd-9", you
just need to use that tag:
$ cd /usr
$ cvs checkout -r netbsd-9 -P src
And for the "xsrc" module:
$ cvs checkout -r netbsd-9 -P xsrc
If you have checked out sources from a stable branch in /usr/src and want to
update them to get the latest security and bug fixes, run:
$ cd /usr/src
$ cvs update -dP
The same applies to the "xsrc" module, but in that case you will have to change
your working directory to /usr/xsrc first.
32.4.3. Æetching the NetBSD-current development branch
To obtain the NetBSD-current source just omit "-r <BRANCH>" and replace it with
"-A":
$ cd /usr
$ cvs checkout -A -P src
The "xsrc" module is obtained the same way:
$ cd /usr
$ cvs checkout -A -P xsrc
To update your NetBSD-current source tree, add the -A flag:
$ cd /usr/src
$ cvs update -A -dP
The same applies to the "xsrc" module, but in that case you will have to change
your working directory to /usr/xsrc first.
32.4.4. Óaving some cvs(1) options
If you find yourself typing the same options to CVS over and over again, you
may want to make those options the default by adding them to .cvsrc in your
home directory. In the following example, cvs update will add any missing
newly-added directories to your tree, as well as delete any newly-empty
directories. Also shown are examples of how to make cvs rdiff and cvs diff use
the unified diff(1) format. The final line in the example causes CVS to be a
bit more quiet in its operation.
Example2.1.cvsrc
update -dP
rdiff -u
diff -u
cvs -q
Chapter3. Ãrosscompiling NetBSD with build.sh
Table of Contents
33.1. Building the toolchain
33.2. Configuring the kernel manually
33.3. Building the kernel manually
33.4. Building the kernel with build.sh
33.5. Building the userland
33.6. Building the X Window System
33.7. Changing build behaviour
33.7.1. Changing the Destination Directory
33.7.2. Static Builds
33.7.3. Using build.sh options
33.7.4. make(1) variables used during build
NetBSD uses a framework, build.sh, to build both the operating system's kernel
and the whole userland for either the same platform as the host machine, or for
a different platform, using cross-compilation. build.sh will take care of
creating all the tools required to build NetBSD for a given platform, and make
them available ready to use for development work.
In this chapter, we will show how to use build.sh to first create a toolchain,
including compiler, assembler, linker and so on, then use it to cross-compile a
NetBSD kernel and userspace for AArch64 on an AMD64 host machine. While native
kernel builds are covered in Chapter4, Compiling the kernel, using the
build.sh script is generally preferred for building the entire of NetBSD.
Before starting, we have placed the sources in a subdirectory of our user's
home directory: /home/nia/cvs/src. While /usr/src is the traditional location
for NetBSD sources, as described in Chapter2, Obtaining the sources, we would
like to build the operating system as an unprivileged (non-root) user.
A more detailed description of the build.sh framework can be found in Luke
Mewburn and Matthew Green's paper and their presentation from BSDCon 2003 as
well as in /usr/src/BUILDING.
33.1. Âuilding the toolchain
The first step to do cross-development is to get all the necessary tools
available. In NetBSD terminology, this is called the "toolchain", and it
includes BSD-compatible make(1), C/C++ compilers, linker, assembler, config(8),
as well as a fair number of tools that are only required when crosscompiling a
full NetBSD release, which we won't cover here.
The command to create the toolchain is quite simple, using NetBSD's src/
build.sh script. Please note that all the commands here can be run as normal
(non-root) user:
$ cd /home/nia/cvs/src
$ ./build.sh -U -O ~/obj -j2 -m evbarm -a aarch64 tools
* The "-U" option indicates we are doing an unprivileged build, as a non-root
user, typically with the source code located somewhere other than /usr/src
* The "-O" option specifies the directory to use for compiled object files.
* The "-j2" option specifies the number of parallel builds to run. You may
wish to set this to the number of CPU cores on your host system.
* The "-a evbarm -m aarch64" options indicate we are building for a machine
type of evbarm with a CPU type of aarch64. You can list the available
machines and CPU types:
$ ./build.sh list-arch
If the tools have been built previously and they only need to be updated, then
the update option "-u" can be used to only rebuild tools that have changed:
$ ./build.sh -U -u -O ~/obj -j2 -m evbarm -a aarch64 tools
When the tools are built, information about them and several environment
variables is printed out:
===> Tools built to /home/nia/obj/tooldir.NetBSD-9.99.81-amd64
===> build.sh ended: Sun Apr 18 12:10:58 CEST 2021
===> Summary of results:
build.sh command: ./build.sh -U -u -O /home/nia/obj -j2 -m evbarm -a aarch64 tools
build.sh started: Sun Apr 18 11:17:46 CEST 2021
NetBSD version: 9.99.81
MACHINE: evbarm
MACHINE_ARCH: aarch64
Build platform: NetBSD 9.99.81 amd64
HOST_SH: /bin/sh
No $TOOLDIR/bin/nbmake, needs building.
Bootstrapping nbmake
MAKECONF file: /etc/mk.conf
TOOLDIR path: /home/nia/obj/tooldir.NetBSD-9.99.81-amd64
DESTDIR path: /home/nia/obj/destdir.evbarm
RELEASEDIR path: /home/nia/obj/releasedir
Created /home/nia/obj/tooldir.NetBSD-9.99.81-amd64/bin/nbmake
Updated makewrapper: /home/nia/obj/tooldir.NetBSD-9.99.81-amd64/bin/nbmake-evbarm
Tools built to /home/nia/obj/tooldir.NetBSD-9.99.81-amd64
build.sh ended: Sun Apr 18 12:10:58 CEST 2021
During the build, object directories are used consistently, i.e. special
directories are kept that keep the platform-specific object files and compile
results. In our example, they will be kept in directories named "obj.evbarm" as
we build for AArch64 as target platform.
The toolchain itself is part of this, but as it's hosted and compiled for an
amd64 system, it will get placed in its own directory indicating where to
cross-build from. Here's where our toolchain is located:
$ pwd
/home/nia/cvs/src
$ ls -d ~/obj/tooldir*
/home/nia/obj/tooldir.NetBSD-9.99.81-amd64
So, the general rule of thumb is for a given "host" and "target" system
combination, the cross-compiler will be placed in the "tooldir.host" directory
by default. A full list of all tools created for cross-compiling the whole
NetBSD operating system includes:
$ ls ~/obj/tooldir.NetBSD-9.99.81-amd64/bin
aarch64--netbsd-addr2line nbconfig nbmkcsmapper
aarch64--netbsd-ar nbcrunchgen nbmkdep
aarch64--netbsd-as nbctags nbmkesdb
aarch64--netbsd-c++ nbctfconvert nbmklocale
aarch64--netbsd-c++filt nbctfmerge nbmknod
aarch64--netbsd-cpp nbcvslatest nbmktemp
aarch64--netbsd-dbsym nbdb nbmkubootimage
aarch64--netbsd-elfedit nbdisklabel nbmsgc
aarch64--netbsd-fdisk nbdtc nbmtree
aarch64--netbsd-g++ nbeqn nbnroff
aarch64--netbsd-gcc nbfile nbpax
aarch64--netbsd-gcc-9.3.0 nbgenassym nbpaxctl
aarch64--netbsd-gcc-ar nbgencat nbperf
aarch64--netbsd-gcc-nm nbgmake nbpic
aarch64--netbsd-gcc-ranlib nbgpt nbpwd_mkdb
aarch64--netbsd-gcov nbgrep nbrefer
aarch64--netbsd-gcov-dump nbgroff nbrpcgen
aarch64--netbsd-gcov-tool nbhexdump nbsed
aarch64--netbsd-install nbhost-mkdep nbslc
aarch64--netbsd-ld nbindxbib nbsoelim
aarch64--netbsd-ld.bfd nbinstall-info nbsortinfo
aarch64--netbsd-mdsetimage nbinstallboot nbstat
aarch64--netbsd-nm nbjoin nbstrfile
aarch64--netbsd-objcopy nblex nbsunlabel
aarch64--netbsd-objdump nbllvm-tblgen nbtbl
aarch64--netbsd-ranlib nblorder nbtexi2dvi
aarch64--netbsd-readelf nbm4 nbtexi2pdf
aarch64--netbsd-size nbmake nbtexindex
aarch64--netbsd-strings nbmake-evbarm nbtic
aarch64--netbsd-strip nbmakefs nbtsort
nbasn1_compile nbmakeinfo nbuudecode
nbawk nbmakekeys nbxz
nbcap_mkdb nbmakestrs nbyacc
nbcat nbmakewhatis nbzic
nbcksum nbmandoc
nbcompile_et nbmenuc
As you can see, most of the tools that are available native on NetBSD are
present with some program prefix to identify the target platform for tools that
are specific to a certain target platform.
One important tool that should be pointed out here is "nbmake-evbarm". This is
a shell wrapper for a BSD compatible make(1) command that's setup to use all
the right commands from the cross-compilation toolchain. Using this wrapper
instead of /usr/bin/make allows crosscompiling programs that were written using
the NetBSD Makefile infrastructure (see src/share/mk). We will use this make(1)
wrapper in a second to cross compile the kernel!
33.2. Ãonfiguring the kernel manually
Now that we have a working toolchain available, the "usual" steps for building
a kernel are needed - create a kernel config file, run config(1), then build.
As the config(1) program used to create header files and Makefile for a kernel
build is platform specific, we need to use the "nbconfig" program that's part
of our new toolchain. That aside, the procedure is just as like compiling a
"native" NetBSD kernel. Commands involved here are:
$ cd /home/nia/cvs/src/sys/arch/evbarm/conf
$ cp GENERIC64 MYKERNEL
$ vi MYKERNEL
$ /home/nia/obj/tooldir.NetBSD-9.99.81-amd64/bin/nbconfig MYKERNEL
That's all. This command has created a directory ../compile/MYKERNEL with a
number of header files defining information about devices to compile into the
kernel, a Makefile that is setup to build all the needed files for the kernel,
and link them together.
33.3. Âuilding the kernel manually
We have all the files and tools available to crosscompile our AArch64-based
kernel from our Intel-based host system, so let's get to it! After changing in
the directory created in the previous step, we need to use the toolchain's
nbmake-evbarm shell wrapper, which just calls make(1) with all the necessary
settings for crosscompiling for an AArch64 platform:
$ cd ../compile/MYKERNEL/
$ /home/nia/obj/tooldir.NetBSD-9.99.81-amd64/bin/nbmake-evbarm depend
$ /home/nia/obj/tooldir.NetBSD-9.99.81-amd64/bin/nbmake-evbarm
This will churn away a bit, then spit out a kernel:
...
text data bss dec hex filename
11131832 3627920 1738912 16498664 fbbfe8 netbsd
...
$ ls -lh netbsd
-rwxr-xr-x 1 nia wheel 16M Apr 18 12:46 netbsd
$ file netbsd
netbsd: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), statically linked, for NetBSD 9.99.81, not stripped
Note
Since we are building for AArch64, a few other kernel images in different
formats were built, including netbsd.img and netbsd.bin for the U-Boot /boot
partition. On systems with more standard boot procedures, you only need to
worry about netbsd.
Now the kernel in the file netbsd can be transferred to a machine (via scp,
rsync, etc.) and booted.
After configuring and crosscompiling the kernel, the next logical step is to
crosscompile the whole system, and bring it into a distribution-ready format.
Before doing so, an alternative approach to crosscompiling a kernel will be
shown in the next section, using the build.sh script to do configuration and
crosscompilation of the kernel in one step.
33.4. Âuilding the kernel with build.sh
A cross compiled kernel can be done manually as described in the previous
sections, or by the easier method of using build.sh, which will be shown here.
Preparation of the kernel config file is the same as described above:
$ cd /home/nia/cvs/src/sys/arch/evbarm/conf
$ cp GENERIC64 MYKERNEL
$ vi MYKERNEL
Then edit MYKERNEL and once finished, all that needs to be done is to use
build.sh to build the kernel (it will also configure it, running the steps
shown above):
$ cd /home/nia/cvs/src
$ ./build.sh -U -u -j2 -O ~/obj -m evbarm -a aarch64 kernel=MYKERNEL
Notice that update ("-u") was specified, the tools are already built, there is
no reason to rebuild all of the tools. Once the kernel is built, build.sh will
print out the location of it along with other information:
...
===> Summary of results:
build.sh command: ./build.sh -O /home/nia/obj -U -u -j2 -m evbarm -a aarch64 kernel=MYKERNEL
build.sh started: Sun Apr 18 12:25:16 CEST 2021
NetBSD version: 9.99.81
MACHINE: evbarm
MACHINE_ARCH: aarch64
Build platform: NetBSD 9.99.81 amd64
HOST_SH: /bin/sh
MAKECONF file: /etc/mk.conf
TOOLDIR path: /home/nia/obj/tooldir.NetBSD-9.99.81-amd64
DESTDIR path: /home/nia/obj/destdir.evbarm
RELEASEDIR path: /home/nia/obj/releasedir
Updated makewrapper: /home/nia/obj/tooldir.NetBSD-9.99.81-amd64/bin/nbmake-evbarm
Building kernel without building new tools
Building kernel: MYKERNEL
Build directory: /home/nia/obj/sys/arch/evbarm/compile/MYKERNEL
Kernels built from MYKERNEL:
/home/nia/obj/sys/arch/evbarm/compile/MYKERNEL/netbsd
build.sh ended: Sun Apr 18 12:46:26 CEST 2021
===> .
The path to the kernel built is of interest here: /home/nia/obj/sys/arch/evbarm
/compile/MYKERNEL/netbsd, it can be used the same way as described above.
33.5. Âuilding the userland
By now it is probably becoming clear that the toolchain actually works in
stages. First the toolchain is built, then a kernel. Since build.sh will
attempt to rebuild the tools at every invocation, using "update" saves time. It
is probably also clear that outside of a few options, the build.sh semantics
are basically build.sh command. So, it stands to reason that building the whole
userland and/or a release is a matter of using the right commands.
It should be no surprise that building and creating a release would look like
the following:
$ ./build.sh -U -u -j2 -O ~/obj -m evbarm -a aarch64 release
These commands will compile the full NetBSD userland and put it into the
destination object directory, and then build a release from it in a release
subdirectory.
33.6. Âuilding the X Window System
The NetBSD project has its own copy of the X Window System's which contains
changes to make X function well on as many of the platforms supported by NetBSD
as possible. Due to this, it is desirable to use the X Window System version
available from and for NetBSD, which can also be crosscompiled much like the
kernel and base system. To do so, the "xsrc" sources must be checked out from
CVS into just as "src" and "pkgsrc" were as described in Chapter2, Obtaining
the sources.
After this, X can be crosscompiled for the target platform by adding the -x
switch to build.sh, e.g. when creating a full release:
$ ./build.sh -U -u -O ~/obj -j2 -x -X /home/nia/cvs/xsrc -m evbarm -a aarch64 release
The -x option automatically sets the variable to build X11, and -X points to
the directory containing the X11 sources.
33.7. Ãhanging build behaviour
The build system has a lot of variables that can be used to direct things like
where certain files go, what (if any) tools are used and so on. A look in src/
BUILDING covers most of them. In this section some examples of changing default
settings are given, each following its own ways.
33.7.1. Ãhanging the Destination Directory
Many people like to track NetBSD-current and perform cross compiles of
architectures that they use. The logic for this is simple, sometimes a new
feature or device becomes available and someone may wish to use it. By keeping
track of changes and building every now and again, one can be assured that
these architectures can build their own release.
It is reasonable to assume that if one is tracking and building for more than
one architecture, they might want to keep the builds in a different location
than the default. There are two ways to go about this, either use a script to
set the new DESTDIR, or simply do so interactively. In any case, it can be set
the same way as any other variable (depending on your shell of course).
For sh(1), or ksh(1), this is:
$ export DESTDIR=/usr/builds/evbarm-aarch64
For csh(1), the command is:
$ setenv DESTDIR /usr/builds/evbarm-aarch64
Simple enough. When the build is run, the binaries and files will be sent to /
usr/builds.
33.7.2. Ótatic Builds
The NetBSD toolchain builds and links against shared libraries by default. Many
users still prefer to be able to link statically. Sometimes a small system can
be created without having shared libraries, which is a good example of doing a
full static build. If a particular build machine will always need one
environment variable set in a particular way, then it is easiest to simply add
the changed setting to /etc/mk.conf.
To make sure a build box always builds statically, simply add the following
line to /etc/mk.conf:
LDSTATIC=-static
33.7.3. Õsing build.sh options
Besides variables in environment and /etc/mk.conf, the build process can be
influenced by a number of switches to the build.sh script itself, as we have
already seen when forcing unprivileged (non-root) builds, selecting the target
architecture or preventing deletion of old files before the build. All these
options can be listed by running build.sh -h:
$ cd /home/nia/cvs/src
$ build.sh -h
Usage: build.sh [-EhnoPRrUuxy] [-a arch] [-B buildid] [-C cdextras]
[-c compiler] [-D dest] [-j njob] [-M obj] [-m mach]
[-N noisy] [-O obj] [-R release] [-S seed] [-T tools]
[-V var=[value]] [-w wrapper] [-X x11src] [-Y extsrcsrc]
[-Z var]
operation [...]
Build operations (all imply "obj" and "tools"):
build Run "make build".
distribution Run "make distribution" (includes DESTDIR/etc/ files).
release Run "make release" (includes kernels & distrib media).
Other operations:
help Show this message and exit.
makewrapper Create nbmake-${MACHINE} wrapper and nbmake.
Always performed.
cleandir Run "make cleandir". [Default unless -u is used]
dtb Build devicetree blobs.
obj Run "make obj". [Default unless -o is used]
tools Build and install tools.
install=idir Run "make installworld" to `idir' to install all sets
except `etc'. Useful after "distribution" or "release"
kernel=conf Build kernel with config file `conf'
kernel.gdb=conf Build kernel (including netbsd.gdb) with config
file `conf'
releasekernel=conf Install kernel built by kernel=conf to RELEASEDIR.
kernels Build all kernels
installmodules=idir Run "make installmodules" to `idir' to install all
kernel modules.
modules Build kernel modules.
rumptest Do a linktest for rump (for developers).
sets Create binary sets in
RELEASEDIR/RELEASEMACHINEDIR/binary/sets.
DESTDIR should be populated beforehand.
distsets Same as "distribution sets".
sourcesets Create source sets in RELEASEDIR/source/sets.
syspkgs Create syspkgs in
RELEASEDIR/RELEASEMACHINEDIR/binary/syspkgs.
iso-image Create CD-ROM image in RELEASEDIR/images.
iso-image-source Create CD-ROM image with source in RELEASEDIR/images.
live-image Create bootable live image in
RELEASEDIR/RELEASEMACHINEDIR/installation/liveimage.
install-image Create bootable installation image in
RELEASEDIR/RELEASEMACHINEDIR/installation/installimage.
disk-image=target Create bootable disk image in
RELEASEDIR/RELEASEMACHINEDIR/binary/gzimg/target.img.gz.
params Display various make(1) parameters.
list-arch Display a list of valid MACHINE/MACHINE_ARCH values,
and exit. The list may be narrowed by passing glob
patterns or exact values in MACHINE or MACHINE_ARCH.
Options:
-a arch Set MACHINE_ARCH to arch. [Default: deduced from MACHINE]
-B buildid Set BUILDID to buildid.
-C cdextras Append cdextras to CDEXTRA variable for inclusion on CD-ROM.
-c compiler Select compiler:
clang
gcc
[Default: gcc]
-D dest Set DESTDIR to dest. [Default: destdir.MACHINE]
-E Set "expert" mode; disables various safety checks.
Should not be used without expert knowledge of the build
system.
-h Print this help message.
-j njob Run up to njob jobs in parallel; see make(1) -j.
-M obj Set obj root directory to obj; sets MAKEOBJDIRPREFIX.
Unsets MAKEOBJDIR.
-m mach Set MACHINE to mach. Some mach values are actually
aliases that set MACHINE/MACHINE_ARCH pairs.
[Default: deduced from the host system if the host
OS is NetBSD]
-N noisy Set the noisyness (MAKEVERBOSE) level of the build:
0 Minimal output ("quiet")
1 Describe what is occurring
2 Describe what is occurring and echo the actual
command
3 Ignore the effect of the "@" prefix in make commands
4 Trace shell commands using the shell's -x flag
[Default: 2]
-n Show commands that would be executed, but do not execute them.
-O obj Set obj root directory to obj; sets a MAKEOBJDIR pattern.
Unsets MAKEOBJDIRPREFIX.
-o Set MKOBJDIRS=no; do not create objdirs at start of build.
-P Set MKREPRO and MKREPRO_TIMESTAMP to the latest source
CVS timestamp for reproducible builds.
-R release Set RELEASEDIR to release. [Default: releasedir]
-r Remove contents of TOOLDIR and DESTDIR before building.
-S seed Set BUILDSEED to seed. [Default: NetBSD-majorversion]
-T tools Set TOOLDIR to tools. If unset, and TOOLDIR is not set in
the environment, nbmake will be (re)built
unconditionally.
-U Set MKUNPRIVED=yes; build without requiring root privileges,
install from an UNPRIVED build with proper file permissions.
-u Set MKUPDATE=yes; do not run "make cleandir" first.
Without this, everything is rebuilt, including the tools.
-V var=[value] Set variable `var' to `value'.
-w wrapper Create nbmake script as wrapper.
[Default: ${TOOLDIR}/bin/nbmake-${MACHINE}]
-X x11src Set X11SRCDIR to x11src. [Default: /usr/xsrc]
-x Set MKX11=yes; build X11 from X11SRCDIR
-Y extsrcsrc Set EXTSRCSRCDIR to extsrcsrc. [Default: /usr/extsrc]
-y Set MKEXTSRC=yes; build extsrc from EXTSRCSRCDIR
-Z var Unset ("zap") variable `var'.
As can be seen, a number of switches can be set to change the standard build
behaviour. A number of them has already been introduced, others can be set as
appropriate.
33.7.4. íake(1) variables used during build
Several variables control the behaviour of NetBSD builds. Unless otherwise
specified, these variables may be set in either the process environment or in
the make(1) configuration file specified by MAKECONF. For a definitive list of
these options, see BUILDING and share/mk/bsd.README files in the toplevel
source directory.
BUILDID
Identifier for the build. The identifier will be appended to object
directory names, and can be consulted in the make(1) configuration file in
order to set additional build parameters, such as compiler flags.
DESTDIR
Directory to contain the built NetBSD system. If set, special options are
passed to the compilation tools to prevent their default use of the host
system's /usr/include, /usr/lib, and so forth. This pathname should not end
with a slash (/) character (For installation into the system's root
directory, set DESTDIR to an empty string). The directory must reside on a
filesystem which supports long filenames and hard links.
Defaults to an empty string if USETOOLS is "yes"; unset otherwise. Note:
build.sh will provide a default (destdir.MACHINE in the top-level .OBJDIR)
unless run in "expert" mode.
EXTERNAL_TOOLCHAIN
If defined by the user, points to the root of an external toolchain (e.g. /
usr/local/gnu). This enables the cross-build framework even when default
toolchain is not available (see TOOLCHAIN_MISSING below).
Default: Unset
MAKEVERBOSE
The verbosity of build messages. Supported values:
+-------------------------------------------------------------------------+
|0|No descriptive messages are shown. |
|-+-----------------------------------------------------------------------|
|1|Descriptive messages are shown. |
|-+-----------------------------------------------------------------------|
|2|Descriptive messages are shown (prefixed with a '#') and command output|
| |is not suppressed. |
+-------------------------------------------------------------------------+
Default: 2
MKCATPAGES
Can be set to "yes" or "no". Indicates whether preformatted plaintext
manual pages will be created during a build.
Default: "yes"
MKDOC
Can be set to "yes" or "no". Indicates whether system documentation
destined for DESTDIR/usr/share/doc will be installed during a build.
Default: "yes"
MKHOSTOBJ
Can be set to "yes" or "no". If set to "yes", then for programs intended to
be run on the compile host, the name, release and architecture of the host
operating system will be suffixed to the name of the object directory
created by "make obj". This allows for multiple host systems to compile
NetBSD for a single target. If set to "no", then programs built to be run
on the compile host will use the same object directory names as programs
built to be run on the target.
Default: "no"
MKINFO
Can be set to "yes" or "no". Indicates whether GNU info files, used for the
documentation of most of the compilation tools, will be created and
installed during a build.
Default: "yes"
MKLINT
Can be set to "yes" or "no". Indicates whether lint(1) will be run against
portions of the NetBSD source code during the build, and whether lint
libraries will be installed into DESTDIR/usr/libdata/lint
Default: "yes"
MKMAN
Can be set to "yes" or "no". Indicates whether manual pages will be
installed during a build.
Default: "yes"
MKNLS
Can be set to "yes" or "no". Indicates whether Native Language System
locale zone files will be compiled and installed during a build.
Default: "yes"
MKOBJ
Can be set to "yes" or "no". Indicates whether object directories will be
created when running "make obj". If set to "no", then all built files will
be located inside the regular source tree.
Default: "yes"
MKPIC
Can be set to "yes" or "no". Indicates whether shared objects and libraries
will be created and installed during a build. If set to "no", the entire
build will be statically linked.
Default: Platform dependent. As of this writing, all platforms except sh3
default to "yes"
MKPICINSTALL
Can be set to "yes" or "no". Indicates whether the ar(1) format libraries
(lib*_pic.a), used to generate shared libraries, are installed during a
build.
Default: "yes"
MKPROFILE
Can be set to "yes" or "no". Indicates whether profiled libraries
(lib*_p.a) will be built and installed during a build.
Default: "yes"; however, some platforms turn off MKPROFILE by default at
times due to toolchain problems with profiled code.
MKSHARE
Can be set to "yes" or "no". Indicates whether files destined to reside in
DESTDIR/usr/share will be built and installed during a build. If set to "no
", then all of MKCATPAGES, MKDOC, MKINFO, MKMAN and MKNLS will be set to "
no" unconditionally.
Default: "yes"
MKTTINTERP
Can be set to "yes" or "no". For X builds, decides if the TrueType bytecode
interpreter is turned on. See freetype.org for details.
Default: "no"
MKUNPRIVED
Can be set to "yes" or "no". Indicates whether an unprivileged install will
occur. The user, group, permissions and file flags will not be set on the
installed items; instead the information will be appended to a file called
METALOG in DESTDIR. The contents of METALOG are used during the generation
of the distribution tar files to ensure that the appropriate file ownership
is stored.
Default: "no"
MKUPDATE
Can be set to "yes" or "no". Indicates whether all install operations
intended to write to DESTDIR will compare file timestamps before
installing, and skip the install phase if the destination files are
up-to-date. This also has implications on full builds (See below).
Default: "no"
MKLLVM
Can be set to "yes" or "no". Indicates whether Clang should be built and
installed as the host compiler.
Default: "no"
MKX11
Can be set to "yes" or "no". Indicates whether X11 is built from X11SRCDIR.
Default: "yes"
TOOLDIR
Directory to hold the host tools, once built. This directory should be
unique to a given host system and NetBSD source tree. (However, multiple
targets may share the same TOOLDIR; the target-dependent files have unique
names). If unset, a default based on the uname(1) information of the host
platform will be created in the .OBJDIR of src.
Default: Unset.
USETOOLS
Indicates whether the tools specified by TOOLDIR should be used as part of
a build in progress. Must be set to "yes" if cross-compiling.
+-------------------------------------------------------------------------+
| yes |Use the tools from TOOLDIR. |
|-----+-------------------------------------------------------------------|
| |Do not use the tools from TOOLNAME, but refuse to build native |
| no |compilation tool components that are version-specific for that |
| |tool. |
|-----+-------------------------------------------------------------------|
| |Do not use the tools from TOOLNAME, even when building native tool |
| |components. This is similar to the traditional NetBSD build method,|
|never|but does not verify that the compilation tools in use are |
| |up-to-date enough in order to build the tree successfully. This may|
| |cause build or runtime problems when building the whole NetBSD |
| |source tree. |
+-------------------------------------------------------------------------+
Default: "yes" if building all or part of a whole NetBSD source tree
(detected automatically); "no" otherwise (to preserve traditional semantics
of the bsd.*.mk make(1) include files).
X11SRCDIR
Directory containing the X11 source.
Default: "usr/xsrc"
The following variables only affect the top level Makefile and do not affect
manually building subtrees of the NetBSD source code.
INSTALLWORLDDIR
Location for the "make installworld" target to install to.
Default: "/"
MKOBJDIRS
Can be set to "yes" or "no". Indicates whether object directories will be
created automatically (via a "make obj" pass) at the start of a build.
Default: "no"
MKUPDATE
Can be set to "yes" or "no". If set, then addition to the effects described
for MKUPDATE=yes above, this implies the effect of NOCLEANDIR (i.e., "make
cleandir" is avoided).
Default: "no"
NOCLEANDIR
If set, avoids the "make cleandir" phase of a full build. This has the
effect of allowing only changed files in a source tree to recompiled. This
can speed up builds when updating only a few files in the tree.
Default: Unset
NODISTRIBDIRS
If set, avoids the "make distrib-dirs" of a full build. This skips running
mtree(8) on DESTDIR, useful on systems where building as an unprivileged
user, or where it is known that the system wide mtree files have not
changed.
Default: Unset
NOINCLUDES
If set, avoids the "make includes" phase of a full build. This has the
effect of preventing make(1) from thinking that some programs are
out-of-date simply because system include files have changed. However, this
option should not be trusted when updating the entire NetBSD source tree
arbitrarily; it is suggested to use MKUPDATE=yes in that case.
Default: Unset
RELEASEDIR
If set, specifies the directory to which a release(7) layout will be
written at the end of a "make release".
Default: Unset
TOOLCHAIN_MISSING
Set to "yes" on platforms for which there is no working in-tree toolchain,
or if you need/wish using native system toolchain (i.e. non-cross tools
available via your shell search path).
Default: depends on target platform; on platforms with in-tree toolchain is
set to "no".
Chapter4. Ãompiling the kernel
Table of Contents
34.1. Requirements and procedure
34.2. Installing the kernel sources
34.3. Creating the kernel configuration file
34.4. Building the kernel manually
34.4.1. Configuring the kernel manually
34.4.2. Generating dependencies and recompiling manually
34.5. Building the kernel using build.sh
34.6. Installing the new kernel
34.7. If something went wrong
There are several reasons you might want to compile a NetBSD kernel:
* you can install bug-fixes, security updates, or new functionality by
rebuilding the kernel from updated sources.
* by removing unused device drivers and kernel sub-systems from your
configuration, you can dramatically reduce kernel size and, therefore,
memory usage and attack surface. Care must be taken when doing this, since
it can result in an unusable system. Always back up old working kernels.
* you can access additional features by enabling kernel options or
sub-systems, some of which are experimental or disabled by default.
* you can get a deeper knowledge of the system.
34.1. Òequirements and procedure
To recompile the kernel you must have installed the compiler set (comp.tgz).
The basic steps to an updated or customised kernel then are:
1. Install or update the kernel sources
2. Create or modify the kernel configuration file
3. Building the kernel from the configuration file, either manually or using
build.sh
4. Install the kernel
34.2. Énstalling the kernel sources
You can get the kernel sources from AnonCVS (see Chapter2, Obtaining the
sources), or from the syssrc.tgz tarball that is located in the source/sets/
directory of the release that you are using.
If you chose to use AnonCVS to fetch the entire source tree, be patient, the
operation can last many minutes, because the repository contains thousands of
files.
If you have a source tarball, you can extract it as root:
# cd /
# tar zxf /path/to/syssrc.tgz
Even if you used the tarball from the release, you may wish to use AnonCVS to
update the sources with changes that have been applied since the release. This
might be especially relevant if you are updating the kernel to include the fix
for a specific bug, including a vulnerability described in a NetBSD Security
Advisory. You might want to get the latest sources on the relevant release or
critical updates branch for your version, or Security Advisories will usually
contain information on the dates or revisions of the files containing the
specific fixes concerned. See Section2.4, "Fetching by CVS" for more details
on the CVS commands used to update sources from these branches.
Once you have the sources available, you can create a custom kernel: this is
not as difficult as you might think. In fact, a new kernel can be created in a
few steps which will be described in the following sections.
34.3. Ãreating the kernel configuration file
Note
The directories described in this section are amd64 specific. Users of other
architectures must substitute the appropriate directories, see the
subdirectories of src/sys/arch for a list.
The kernel configuration file defines the type, the number and the
characteristics of the devices supported by the kernel as well as several
kernel configuration options. For the amd64 port, kernel configuration files
are located in the /usr/src/sys/arch/amd64/conf directory.
Please note that the names of the kernel configuration files are historically
in all uppercase, so they are easy to distinguish from other files in that
directory:
$ cd /usr/src/sys/arch/amd64/conf/
$ ls
ALL INSTALL XEN3_DOM0 kern.ldscript.kaslr
CVS INSTALL_XEN3_DOMU XEN3_DOMU majors.amd64
GENERIC MODULAR files.amd64 std.amd64
GENERIC_KASLR Makefile.amd64 kern.ldscript std.xen
GENERIC_USERMODE NOCOMPAT kern.ldscript.Xen
The easiest way to create a new file is to copy an existing one and modify it.
Usually the best choice on most platforms is the GENERIC configuration, as it
contains most drivers and options. In the configuration file there are comments
describing the options; a more detailed description is found in the options(4)
man page. So, the usual procedure is:
$ cp GENERIC MYKERNEL
$ vi MYKERNEL
The modification of a kernel configuration file basically involves three
operations:
1. support for hardware devices is included/excluded in the kernel (for
example, SCSI support can be removed if it is not needed.)
2. support for kernel features is enabled/disabled (for example, enable NFS
client support, enable Linux compatibility, ...)
3. tuning kernel parameters.
Lines beginning with "#" are comments; lines are disabled by commenting them
and enabled by removing the comment character. It is better to comment lines
instead of deleting them; it is always possible uncomment them later.
The output of the dmesg(8) command can be used to determine which lines can be
disabled. For each line of the type:
XXX at YYY
both XXX and YYY must be active in the kernel configuration file. You'll
probably have to experiment a bit before achieving a minimal configuration but
on a desktop system without SCSI and PCMCIA you can halve the kernel size.
You could also examine the options in the configuration file and disable the
ones that you don't need. Each option has a short comment describing it, which
is normally sufficient to understand what the option does. Many options have a
longer and more detailed description in the options(4) man page.
34.4. Âuilding the kernel manually
Based on your kernel configuration file, either one of the standard
configurations or your customised configuration, a new kernel must be built.
These steps can either be performed manually, or using the build.sh command
that was introduced in section Chapter3, Crosscompiling NetBSD with build.sh.
This section will give instructions on how to build a native kernel using
manual steps, the following section Section4.5, "Building the kernel using
build.sh" describes how to use build.sh to do the same.
* Configure the kernel
* Generate dependencies
* Compile the kernel
34.4.1. Ãonfiguring the kernel manually
When you've finished modifying the kernel configuration file (which we'll call
MYKERNEL), you should issue the following command:
$ config MYKERNEL
If MYKERNEL contains no errors, the config(1) program will create the necessary
files for the compilation of the kernel, otherwise it will be necessary to
correct the errors before running config(1) again.
Notes for cross-compiling
As the config(1) program used to create header files and Makefile for a kernel
build is platform specific, it is necessary to use the nbconfig program that's
part of a newly created toolchain (created for example with
/usr/src/build.sh -m sparc64 tools
). That aside, the procedure is just as like compiling a "native" NetBSD
kernel. The command is for example:
% /usr/src/tooldir.NetBSD-9.0-amd64/bin/nbconfig MYKERNEL
This command has created a directory ../compile/MYKERNEL with a number of
header files defining information about devices to compile into the kernel, a
Makefile that is setup to build all the needed files for the kernel, and link
them together.
34.4.2. Çenerating dependencies and recompiling manually
Dependencies generation and kernel compilation is performed by the following
commands:
$ cd ../compile/MYKERNEL
$ make depend
$ make
It can happen that the compilation stops with errors; there can be a variety of
reasons but the most common cause is an error in the configuration file which
didn't get caught by config(1). Sometimes the failure is caused by a hardware
problem (often faulty RAM chips): the compilation puts a higher stress on the
system than most applications do. Another typical error is the following:
option B, active, requires option A which is not active. A full compilation of
the kernel can last from some minutes to several hours, depending on the
hardware.
The result of a successful make command is the netbsd file in the compile
directory, ready to be installed.
Notes for cross-compiling
For crosscompiling a sparc64 kernel, it is necessary to use the crosscompiler
toolchain's nbmake-sparc64 shell wrapper, which calls make(1) with all the
necessary settings for crosscompiling for a sparc64 platform:
% cd ../compile/MYKERNEL/
% /usr/src/tooldir.NetBSD-9.0-amd64/bin/nbmake-sparc64 depend
% /usr/src/tooldir.NetBSD-9.0-amd64/bin/nbmake-sparc64
This will churn away a bit, then spit out a kernel:
...
text data bss dec hex filename
5016899 163728 628752 5809379 58a4e3 netbsd
% ls -l netbsd
-rwxr-xr-x 1 feyrer 666 5874663 Dec 2 23:17 netbsd
% file netbsd
netbsd: ELF 64-bit MSB executable, SPARC V9, version 1 (SYSV), statically linked, not stripped
Now the kernel in the file netbsd can either be transferred to an UltraSPARC
machine (via NFS, FTP, scp, etc.) and booted from a possible harddisk, or
directly from the cross-development machine using NFS.
34.5. Âuilding the kernel using build.sh
After creating and possibly editing the kernel config file, the manual steps of
configuring the kernel, generating dependencies and recompiling can also be
done using the src/build.sh script, all in one go:
$ cd /usr/src
$ ./build.sh kernel=MYKERNEL
This will perform the same steps as above, with one small difference: before
compiling, all old object files will be removed, to start with a fresh build.
This is usually overkill, and it's fine to keep the old file and only rebuild
the ones whose dependencies have changed. To do this, add the -u option to
build.sh:
$ cd /usr/src
$ ./build.sh -u kernel=MYKERNEL
At the end of its job, build.sh will print out the location where the new
compiled kernel can be found. It can then be installed.
34.6. Énstalling the new kernel
Whichever method was used to produce the new kernel file, it must now be
installed. The new kernel file should be copied to the root directory, after
saving the previous version.
# mv /netbsd /netbsd.old
# mv netbsd /
Customization can considerably reduce the kernel's size. In the following
example netbsd.old is the install kernel and netbsd is the new kernel.
-rwxr-xr-x 3 root wheel 3523098 Dec 10 00:13 /netbsd
-rwxr-xr-x 3 root wheel 7566271 Dec 10 00:13 /netbsd.old
The new kernel is activated after rebooting:
# shutdown -r now
34.7. Éf something went wrong
When the computer is restarted it can happen that the new kernel doesn't work
as expected or even doesn't boot at all. Don't worry: if this happens, just
reboot with the previously saved kernel and remove the new one (it is better to
reboot "single user"):
* Reboot the machine
* Press the space bar at the boot prompt during the 5 seconds countdown
boot:
* Type
> boot netbsd.old -s
* Now issue the following commands to restore the previous version of the
kernel:
# fsck /
# mount /
# mv netbsd.old netbsd
# reboot
This will give you back the working system you started with, and you can revise
your custom kernel config file to resolve the problem. In general, it's wise to
start with a GENERIC kernel first, and then make gradual changes.
Chapter5. Õpdating an existing system from sources
Table of Contents
35.1. Manual build and update procedure
35.1.1. Building a new userland
35.1.2. Building a new kernel
35.1.3. Installing the kernel and userland
35.1.4. Updating the system configuration files
35.1.5. Summary
35.2. Using sysinst
35.3. Using sysbuild and sysupgrade
35.3.1. Tweak: Building as non-root
35.3.2. Tweak: Setting up nightly builds
35.4. More details about the updating of configuration and startup files
35.4.1. Using etcupdate with source files
35.4.2. Using etcupdate with binary distribution sets
35.4.3. Using etcmanage instead of etcupdate
A common mechanism for upgrading a NetBSD system to a newer version is by
rebuilding the system from sources and installing the results. This works both
for stable releases such as NetBSD 9.1 and for NetBSD-current. In particular,
if you are running a stable NetBSD release in a production environment, you are
encouraged to perform this procedure regularly in order to incorporate any
security fixes that have been applied to the branch since its release.
There are a variety of ways of achieving the goal of rebuilding NetBSD from
source, and this chapter will guide you through the variety of options that are
available. The chapter starts by showing first what the manual procedure looks
like, and proceeds to describe some of automation tools that simplify the
process.
Note
Please remember to check src/UPDATING for the latest changes and special
instructions that may be involved in upgrading the system.
35.1. Íanual build and update procedure
Most of the following steps can be done as ordinary user. Only the installation
of a new kernel and the userland will require root privileges. Although /usr is
choosen as the working directory in the following examples, the procedure can
also take place in a user's home directory. Ordinary users have normally not
the permissions to make changes in /usr, but this can be changed by root.
Having up-to-date sources is a prerequisite for the following steps.
Section2.4, "Fetching by CVS" informs about the ways to retrieve or update
the sources for a release, stable or current branch (using CVS).
Please always refer to the output of build.sh -h and the files UPDATING and
BUILDING for details - it's worth it, there are many options that can be set on
the command line or in /etc/mk.conf
35.1.1. Âuilding a new userland
The first step is to build the userland:
$ cd /usr/src
$ ./build.sh -O ../obj -T ../tools -U distribution
35.1.2. Âuilding a new kernel
The next step will build the kernel:
$ cd /usr/src
$ ./build.sh -O ../obj -T ../tools -U kernel=<KERNEL>
35.1.3. Énstalling the kernel and userland
Installing the new kernel, rebooting (to ensure that the new kernel works) and
installing the new userland are the final steps of the updating procedure:
$ cd /usr/src
$ su
# mv /netbsd /netbsd.old
# mv /usr/obj/sys/arch/<ARCH>/compile/<KERNEL>/netbsd /
# shutdown -r now
...
$ cd /usr/src
$ su
# ./build.sh -O ../obj -T ../tools -U install=/
If the new kernel netbsd does not boot successfully, you can fall back on
booting the netbsd.old kernel.
35.1.4. Õpdating the system configuration files
Updating your system's configuration files is done in two steps. First,
postinstall(8) is used to check and fix things that can be easily automated.
Afterwards, etcupdate(8) is used to merge the remaining configuration file
changes.
# /usr/sbin/postinstall -s /usr/src check
# /usr/sbin/postinstall -s /usr/src fix
# /usr/sbin/etcupdate -s /usr/src
Optionally reboot to ensure all running services are using the new binaries:
# shutdown -r now
35.1.5. Óummary
1. From the root of the source tree:
$ cd /usr/src
2. Build the userland:
$ ./build.sh -O ../obj -T ../tools -U -u distribution
3. Build the kernel:
$ ./build.sh -O ../obj -T ../tools -U -u kernel=GENERIC
4. Install the kernel:
$ cd ../obj/sys/arch/<ARCH>/compile/GENERIC
$ su
# mv /netbsd /netbsd.old
# cp netbsd /netbsd
5. Reboot into the new kernel:
# shutdown -r now
6. Install the new userland:
$ cd /usr/src
$ su
# ./build.sh -O ../obj -T ../tools -U install=/
7. Update the system and configuration files;:
# /usr/sbin/etcupdate -s /usr/src
Note
In the procedure above, the -u option indicates an update process, and that a
make clean operation should not be run before starting the build. This is
useful when doing an update from a previous build and/or a fresh build. The -U
option allows the entire build by a non-root user followed with an install by
root.
35.2. Õsing sysinst
It is also possible to use sysinst to install a freshly built system. The steps
are as follows:
1. Build a complete release:
$ ./build.sh -O ../obj -T ../tools -U -u -x release
2. The resulting install sets will be in the /usr/obj/releasedir/ directory.
3. Copy the install kernel to the root directory of your NetBSD system, reboot
from it, and upgrade with sysinst (see Chapter, Upgrading NetBSD).
35.3. Õsing sysbuild and sysupgrade
The sysbuild and sysupgrade tools (currently available in pkgsrc/sysutils/
sysbuild and pkgsrc/sysutils/sysupgrade respectively) automate the full process
of rebuilding NetBSD from sources (including the retrieval of the sources from
a CVS repository) and installing the results with minimal effort.
Both of these tools have configuration files to determine how to build a
release and how to install it. Among other things, these specify the CVS
repository to use, what architecture to build for, where to place the build
files and what steps to perform during an upgrade. The files can be found in /
usr/pkg/etc/sysbuild/default.conf and /usr/pkg/etc/sysupgrade.conf. The default
configuration of both tools should let you get started with minimal effort.
In their simplest form, you can do a full NetBSD build and upgrade your system
to it by running these commands:
# sysbuild build
# sysupgrade auto ~/sysbuild/release/$(uname -m)
And that's all that it takes. These invocations will do the following:
1. Download the source trees from CVS into /usr/src and /usr/xsrc. The latter
is only fetched if your system has X11. And, if you already have the
sources in your system, this will only update them to the newest version.
2. Build a new release into ~/sysbuild/<machine>/. This per-machine directory
will include subdirectories like obj, destdir, etc. The build results will
be left in ~/sysbuild/release/<machine>/.
3. Install a new kernel and unpack the new sets using the just-built release
files.
4. Run both etcupdate and postinstall to aid you in merging new configuration
changes into your system.
For more details, please see the included sysbuild(1) and sysupgrade(8) manual
pages, as well as the comments in the referenced configuration files.
35.3.1. Ôweak: Building as non-root
The commands above depict the most basic and simple invocation of the tools
using the default configuration files. One drawback is that you require root
access during the build of the source tree so that sysbuild can upgrade the
source trees under /usr/src and /usr/xsrc. It is recommended that you avoid
building as root once you are familiar with the procedure, and this section
show what is needed to do so with sysbuild.
In order to build as non-root, you can either choose to store your source trees
out of /usr (easiest) or give permissions to your user to modify the trees
under /usr (good if you want to share the source tree with more than one user).
If you want to store the source trees under your home directory, which is
convenient for development purposes, simply edit /usr/pkg/etc/sysbuild.conf and
add these settings:
SRCDIR="${HOME}/sysbuild/src"
[ ! -f /etc/mtree/set.xbase ] || XSRCDIR="${HOME}/sysbuild/xsrc"
Once this is done, the "sysbuild build" invocation show above should just work
under your unprivileged user. The upgrade procedure then becomes:
$ sysbuild build
... become root ...
# sysupgrade auto ~/sysbuild/release/$(uname -m)
The other alternative, in case you want to maintain your source trees in the
locations described by hier(7), is to do the following as root:
# mkdir -p /usr/src /usr/xsrc
# chown -R <your-user>:wsrc /usr/src /usr/xsrc
... and optionally add <your-user> to wsrc in /etc/group ...
After this, the default configuration file of sysbuild will let you place the
files in these locations and let you do unprivileged builds.
35.3.2. Ôweak: Setting up nightly builds
The pkgsrc/sysutils/sysbuild-user package can be used to configure and maintain
an unprivileged system user to perform periodic (e.g. nightly) builds from
source. This can come in very handy to closely track NetBSD-current.
The installed user is appropriately named sysbuild, and is configured by
default to run a full system build overnight. The results are left in /home/
sysbuild/release/<machine>/, which is the convenient default of sysupgrade's
release directory. Any build failures will be reported to you by email.
The behavior of sysbuild for this unprivileged user is configured in /home/
sysbuild/default.conf.
You can interact with sysbuild under this unprivileged user by running commands
of the form:
# su - sysbuild /usr/pkg/bin/sysbuild ...
35.4. Íore details about the updating of configuration and startup files
etcupdate is a script to help users compare, merge and install new
configuration and startup files (files found in the etc.tgz distribution set)
in /dev, /etc and /root after performing an operating system upgrade. The
upgrade of the operating system could have been performed either by compiling
sources or by extracting the distribution binaries.
35.4.1. Õsing etcupdate with source files
In case where the sources are in /usr/src the following command should be
enough:
# etcupdate
But what if your NetBSD sources are in an alternative location, such as in /
home/jdoe/netbsd/src? Don't worry, tell etcupdate the location of your source
tree with -s srcdir and it will work just fine:
# etcupdate -s /home/jdoe/netbsd/src
35.4.2. Õsing etcupdate with binary distribution sets
Sometimes it's not convenient to have the sources around but you still want to
update the configuration and startup files. The solution is to feed etc.tgz (or
xetc.tgz) to etcupdate via the -s tgzfile switch.
# etcupdate -s /some/where/etc.tgz
35.4.3. Õsing etcmanage instead of etcupdate
The etcmanage perl script (available from pkgsrc/sysutils/etcmanage or as
binary package) is an alternative to etcupdate. It should be used in the
following way, in combination with postinstall(8):
# /usr/pkg/bin/etcmanage
# /usr/sbin/postinstall
Chapter6. Âuilding NetBSD installation media
Table of Contents
36.1. Creating standard installation images with build.sh
36.2. Creating custom live disk images
36.1. Ãreating standard installation images with build.sh
For some architectures, you can build a disk or ISO image that boots into an
installer. This is accomplished by running ./build.sh with the targets
install-image (for an USB stick) or iso-image (for a DVD or CD):
$ ./build.sh -U -u -j2 -m amd64 -O ~/obj tools
$ ./build.sh -U -u -j2 -m amd64 -O ~/obj release
$ ./build.sh -U -u -j2 -m amd64 -O ~/obj install-image
Many other ./build.sh targets are available, see Chapter3, Crosscompiling
NetBSD with build.sh.
36.2. Ãreating custom live disk images
Sometimes you may want to create your own customized pre-installed ("live")
images instead of using the precompiled images, for e.g. mass deployment on
embedded systems. This section outlines the steps to do so.
1. You must build a release of NetBSD so there are binaries to fill the image.
See Chapter3, Crosscompiling NetBSD with build.sh for instructions.
2. You must write or pick a sh(1) script from src/distrib/utils/embedded/conf.
Examine the default configurations, and if necessary, customize one to your
needs. The scripts can alter and add to the system configuration files.
3. Run the utility:
$ export MKDTB=no
$ ./distrib/utils/embedded/mkimage -D obj/destdir.amd64 -K sys/arch/amd64/compile/obj/GENERIC/netbsd -h amd64 -x ./example-amd64-image.img
+ In this case, we are building an image for the amd64.conf
configuration, so we specify -h amd64.
+ We want to include the X11 sets, so we specify -x.
+ We need to specify the device type of the root filesystem with e.g. -r
sd. Typically, this is ld(4) for SD/MMC devices, and sd(4) for USB
sticks.
+ We specify MKDTB=no in the environment to avoid building device tree
blobs, which are only used on ARM and MIPS.
4. Make any final additions to the image. This can include installing packages
with pkg_add(1), etc. We mount the image as a virtual disk using vndconfig
(8):
# vndconfig vnd0 ./example-amd64-image.img
# mount /dev/vnd0a /mnt
# pkg_add -P /mnt -K /usr/pkg/pkgdb -v darkstat-3.0.719.tgz
# umount /mnt
5. Write the image to your live media:
# dd if=example-amd64-image.img ibs=1m | progress dd of=/dev/rsd0 obs=1m
Appendix Á. Énformation
Table of Contents
A.1. Where to get this document
A.2. Guide history
A.1. ×here to get this document
This document is currently available in the following formats:
* HTML
* PDF
* gzip'd PostScript
In addition, this guide is also sold on occasion in printed form at tradeshows
and exhibitions, with all profits being donated to the NetBSD Foundation. On
demand printing may at some point be available as well. If you are interested
in obtaining a printed and bound copy of this document, please contact <
www@NetBSD.org>.
A.2. Çuide history
This guide was born as a collection of sparse notes that Federico Lupi, the
original author of the NetBSD Guide, wrote mostly for himself. When he realized
that they could be useful to other NetBSD users he started collecting them and
created the first version of the guide using the groff formatter. In order to "
easily" get a wider variety of output formats (e.g. HTML and PostScript/PDF),
he made the "mistake" of moving to SGML/DocBook, which is the current format of
the sources. Maintainership was picked up by the NetBSD project and its
developers later, and the format was changed to XML/DocBook later due to better
tools and slightly more knowhow on customisations.
The following open source tools were used to write and format the guide:
* the vi editor which ships with NetBSD (nvi).
* the libxslt parser from GNOME for transforming XML/DocBook into HTML.
* the TeX system from the NetBSD packages collection. TeX is used as a
backend to produce the PS and PDF formats.
* the tgif program for drawing the figures.
* the gimp and xv programs for converting between image formats and making
small modifications to the figures.
Many thanks to all the people involved in the development of these great tools.
Appendix Â. Ãontributing to the NetBSD guide
Table of Contents
B.1. Sending contributions
B.2. XML/DocBook template
There is an interest for both introductory and advanced documentation on
NetBSD: this is probably a sign of the increased popularity of this operating
system and of a growing user base. It is therefore important to keep adding new
material to this guide and improving the existing text.
Whatever your level of expertise with NetBSD, you can contribute to the
development of this guide. This appendix explains how, and what you should know
before you start.
If you are a beginner and you found this guide helpful, please send your
comments and suggestions to <www@NetBSD.org>. For example, if you tried
something described here and it didn't work for you, or if you think that
something is not clearly explained, or if you have an idea for a new chapter,
etc: this type of feedback is very useful.
If you are an intermediate or advanced user, please consider contributing new
material to the guide: you could write a new chapter or improve an existing
one.
Whatever you choose to do, don't start working before having contacted us, in
order to avoid duplicating efforts.
B.1. Óending contributions
If you want to contribute some material to the guide you have several options,
depending on the amount of text you want to write. If you just want to send a
small fix, the easiest way to get it into the guide is to send it to <
www@NetBSD.org> via e-mail. If you plan to write a substantial amount of text,
such as a section or a chapter, you can choose among many formats:
* XML/DocBook; this is the preferred format. If you choose to use this
format, please get the guide sources and use them as a template for the
indentation and text layout, in order to keep the formatting consistent.
* text; if the formatting is kept simple, it is not difficult to convert text
to XML format.
* other formats are also accepted if you really can't use any of the previous
ones.
B.2. ØML/DocBook template
For the guide I use a formatting style similar to a program. The following is a
template:
<chapter id="chap-xxxxx">
<title>This is the title of the chapter</title>
<para>
This is the text of a paragraph. This is the text of a paragraph.
This is the text of a paragraph. This is the text of a paragraph.
This is the text of a paragraph.
</para>
<!-- ============================================================= -->
<sect1>
<title>This is the title of a sect1</title>
<para>
This is the text of a paragraph. This is the text of a paragraph.
This is the text of a paragraph. This is the text of a paragraph.
This is the text of a paragraph.
</para>
<!-- ........................................................... -->
<sect2>
<title>This is the title of a sect2</title>
<para>
A sect2 is nested inside a sect1.
</para>
</sect2>
</sect1>
<!-- ============================================================= -->
<sect1>
<title>This is the title of another sect1</title>
<para>
An itemized list:
<itemizedlist>
<listitem>
<para>
text
</para>
</listitem>
<listitem>
<para>
text
</para>
</listitem>
</itemizedlist>
</para>
</sect1>
</chapter>
The defaults are:
* two spaces for each level of indentation
* lines not longer than 72 characters.
* use separator lines (comments) between sect1/sect2.
Appendix Ã. Çetting started with XML/DocBook
Table of Contents
C.1. What is XML/DocBook
C.2. Installing the necessary tools
C.3. Using the tools
C.4. Links
This appendix describes the installation of the tools needed to produce a
formatted version of the NetBSD guide. Besides that it contains instructions
that describe how to build the guide..
C.1. ×hat is XML/DocBook
XML (eXtensible Markup Language) is a language which is used to define other
languages based on markups, i.e. with XML you can define the grammar (i.e. the
valid constructs) of markup languages. HTML, for example, can be defined using
XML. If you are a programmer, think of XML like the BNF (Backus-Naur Form): a
tool used to define grammars.
DocBook is a markup template defined using XML; DocBook lists the valid tags
that can be used in a DocBook document and how they can be combined together.
If you are a programmer, think of DocBook as the grammar of a language
specified with the BNF. For example, it says that the tags:
<para> ... </para>
define a paragraph, and that a <para> can be inside a <sect1> but that a
<sect1> cannot be inside a <para>.
Therefore, when you write a document, you write a document in DocBook and not
in XML: in this respect DocBook is the counterpart of HTML (although the markup
is richer and a few concepts are different).
The DocBook specification (i.e. the list of tags and rules) is called a DTD
(Document Type Definition).
In short, a DTD defines how your source documents look like but it gives no
indication about the format of your final (compiled) documents. A further step
is required: the DocBook sources must be converted to some other representation
like, for example, HTML or PDF. This step is performed by a tool like Jade,
which applies the DSSSL transforms to the source document. DSSSL (Document
Style Semantics and Specification Language) is a format used to define the
stylesheets necessary to perform the conversion from DocBook to other formats.
The build structure for the guide also supports the XSL (Extensible Stylesheet
Language) stylesheet language. The xsltproc program is used for transforming
XML with XSL stylesheets.
C.2. Énstalling the necessary tools
All the tools that are needed to generate the guide in various formats can be
installed through the netbsd-www, netbsd-doc, and netbsd-doc-print
meta-packages. Together the netbsd-doc and netbsd-www packages install
everything that is needed to generate the HTML version of the guide. To be able
to generate printable formats, such as Postscript and PDF, install the
netbsd-doc-print meta-package.
Supposing that a current pkgsrc tree is installed at /usr/pkgsrc, you can
install all these meta-packages with:
$ cd /usr/pkgsrc/meta-pkgs/netbsd-www
$ make install
$ cd /usr/pkgsrc/meta-pkgs/netbsd-doc
$ make install
$ cd /usr/pkgsrc/meta-pkgs/netbsd-doc-print
$ make install
C.3. Õsing the tools
This section provides an overview of how the guide can be compiled from XML to
any of the following target formats: html, html-split, ascii, ps, and pdf.
Creating all formats is the default. To produce any of the above output
formats, run make with the format(s) as argument.
Let's look at a few examples.
Before looking at the output generated in any of the above-mentioned formats,
integrity of the XML structure has to be ensured. This can be done by running
make lint:
$ cd htdocs/docs/guide/en
$ make lint
Fix any errors you may get. When working on the contents of the guide, you may
want to produce the HTML version to have a look at it for proofreading:
$ cd htdocs/docs/guide/en
$ make html-split
After this, please update the Postscript and PDF versions of the guide too. The
command for this is:
$ cd htdocs/docs/guide/en
$ make pdf
Before you go and commit the generated files, please make sure that you commit
the XML files first, then re-generated all formats, i.e. the procedure would be
something like:
$ cd htdocs/docs/guide/en
$ cvs commit *.xml
$
$ make lint
$ make
$ make install-doc
$
$ cd ..
$ cvs commit en download
When running make with no argument, all formats will be re-generated. This is
the default way to build the guide for the NetBSD.org website.
C.4. Ìinks
The official DocBook home page is where you can find the definitive
documentation on DocBook. You can also read online or download a copy of the
book DocBook: The Definitive Guide by Norman Walsh and Leonard Muellner.
For DSSSL start looking at http://nwalsh.com.
XSL is described at http://www.w3.org/Style/XSL/.
Jade/OpenJade sources and info can be found on the OpenJade Home Page.
If you want to produce Postscript and PDF documents from your DocBook source,
look at the home page of JadeTex.
Appendix Ä. Ácknowledgements
Table of Contents
D.1. Original acknowledgements
D.2. Current acknowledgements
D.3. Licenses
D.3.1. Federico Lupi's original license of this guide
D.3.2. Networks Associates Technology's license on the PAM article
D.3.3. Joel Knight's license on the CARP article
The NetBSD Guide was originally written by Federico Lupi who managed the
sources, coordinated updates, and merged all contributions on his own. Since
then, it has been updated and maintained by the NetBSD www team. The Guide has
progressed thanks to the contributions of many people who have volunteered
their time and effort, supplied material and sent in suggestions and
corrections.
D.1. Ïriginal acknowledgements
Federico's original credits are:
* Paulo Aukar
* Grant Beattie, converted to XML DocBook.
* Manolo De Santis, Audio Chapter
* Eric Delcamp, Boot Floppies
* Hubert Feyrer, who contributed the Introduction to TCP/IP Networking in
Chapter5, Introduction to TCP/IP Networking including Next generation
Internet protocol - IPv6 and the section on getting IPv6 Connectivity &
Transition via 6to4 He also helped with the SGML to XML transition.
* Jason R. Fink
* Daniel de Kok, audio and linux chapters fixes.
* Reinoud Koornstra, CVS chapter and rebuilding /dev in the Misc chapter.
* Brian A. Seklecki <lavalamp@burghcom.com> who contributed the CCD Chapter.
* Guillain Seuillot
* Martti Kuparinen, RAIDframe documentation.
* David Magda
D.2. Ãurrent acknowledgements
This document is currently maintained by the NetBSD www team. Thanks to their
efforts, the document is kept up to date and available online at all times. In
addition, special thanks go to (in alphabetical order):
* Hubert Feyrer, for getting the guide up to speed for NetBSD 2.0, and for
making numerous improvements to all chapters.
* Jason R. Fink, for maintaining this document and integrating changes.
* Joel Knight for the Chapter0, Introduction to the Common Address
Redundancy Protocol (CARP). See Section Ä.3.3, "Joel Knight's license on
the CARP article" for the accompanying license.
* Daniel de Kok, for constant contributions of new chapters, maintenance of
existing chapters and his translation work.
* Hiroki Sato, for allowing us to build PDF and PS versions of this document.
* Jan Schaumann, for maintenance work and www/htdocs management.
* Lubomir Sedlacik, for some details on using CGD for swap in Section5.6,
"Suggestions and Warnings".
* Dag-Erling Smøògrav, for the article on Chapter9, Pluggable
Authentication Modules (PAM). See Section Ä.3.2, "Networks Associates
Technology's license on the PAM article" for the accompanying license.
* Florian Stöèr, for Section5.4, "Example: encrypted CDs/DVDs".
D.3. Ìicenses
D.3.1. Æederico Lupi's original license of this guide
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software must
display the following acknowledgement: This product includes software
developed by Federico Lupi for the NetBSD Project.
4. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
OF SUCH DAMAGE.
D.3.2. Îetworks Associates Technology's license on the PAM article
Copyrightc)001-2003 Îetworks Ássociates Ôechnology, Énc.
All òights òeserved.
This óoftware ÷as äeveloped æor ôhe ÆreeBSD Ðroject ây ÔhinkSec ÁS ánd
Network Ássociates Ìaboratories, ôhe Óecurity Òesearch Äivision ïf
Network Ássociates, Énc. under ÄARPA/SPAWAR ãontract Î66001-01-C-8035
("CBOSS"), ás ðart ïf ôhe ÄARPA ÃHATS òesearch ðrogram.
Redistribution ánd õse én óource ánd âinary æorms, ÷ith ïr ÷ithout
modification, áre ðermitted ðrovided ôhat ôhe æollowing ãonditions
are íet:
1. Òedistributions ïf óource ãode íust òetain ôhe ábove ãopyright
îotice, ôhis ìist ïf ãonditions ánd ôhe æollowing äisclaimer.
2. Òedistributions én âinary æorm íust òeproduce ôhe ábove ãopyright
îotice, ôhis ìist ïf ãonditions ánd ôhe æollowing äisclaimer én ôhe
äocumentation ánd/or ïther íaterials ðrovided ÷ith ôhe äistribution.
3. Ôhe îame ïf ôhe áuthor íay îot âe õsed ôo åndorse ïr ðromote
ðroducts äerived ærom ôhis óoftware ÷ithout ópecific ðrior ÷ritten
ðermission.
THIS ÓOFTWARE ÉS ÐROVIDED ÂY ÔHE ÁUTHOR ÁND ÃONTRIBUTORS à`AS ÉS'' ÁND
ANY ÅXPRESS ÏR ÉMPLIED ×ARRANTIES, ÉNCLUDING, ÂUT ÎOT ÌIMITED ÔO, ÔHE
IMPLIED ×ARRANTIES ÏF ÍERCHANTABILITY ÁND ÆITNESS ÆOR Á ÐARTICULAR ÐURPOSE
ARE ÄISCLAIMED. IN ÎO ÅVENT ÓHALL ÔHE ÁUTHOR ÏR ÃONTRIBUTORS ÂE ÌIABLE
FOR ÁNY ÄIRECT, ÉNDIRECT, ÉNCIDENTAL, ÓPECIAL, ÅXEMPLARY, ÏR ÃONSEQUENTIAL
DAMAGESINCLUDING, ÂUT ÎOT ÌIMITED ÔO, ÐROCUREMENT ÏF ÓUBSTITUTE ÇOODS
OR ÓERVICES; ÌOSS ÏF ÕSE, ÄATA, ÏR ÐROFITS; ÏR ÂUSINESS ÉNTERRUPTION)
HOWEVER ÃAUSED ÁND ÏN ÁNY ÔHEORY ÏF ÌIABILITY, ×HETHER ÉN ÃONTRACT, ÓTRICT
LIABILITY, ÏR ÔORTINCLUDING ÎEGLIGENCE ÏR ÏTHERWISE) ÁRISING ÉN ÁNY ×AY
OUT ÏF ÔHE ÕSE ÏF ÔHIS ÓOFTWARE, ÅVEN ÉF ÁDVISED ÏF ÔHE ÐOSSIBILITY ÏF
SUCH ÄAMAGE.
D.3.3. Êoel Knight's license on the CARP article
Copyrightc)005 Êoel Ënightenabled@myrealbox.com>
Permission ôo õse, ãopy, íodify, ánd äistribute ôhis äocumentation æor
any ðurpose ÷ith ïr ÷ithout æee és èereby çranted, ðrovided ôhat ôhe
above ãopyright îotice ánd ôhis ðermission îotice áppear én áll ãopies.
THE ÄOCUMENTATION ÉS ÐROVIDEDAS ÉS" ÁND ÔHE ÁUTHOR ÄISCLAIMS ÁLL
WARRANTIES ×ITH ÒEGARD ÔO ÔHIS ÄOCUMENTATION ÉNCLUDING ÁLL ÉMPLIED
WARRANTIES ÏF ÍERCHANTABILITY ÁND ÆITNESS. ÉN ÎO ÅVENT ÓHALL ÔHE
AUTHOR ÂE ÌIABLE ÆOR ÁNY ÓPECIAL, ÄIRECT, ÉNDIRECT, ÏR ÃONSEQUENTIAL
DAMAGES ÏR ÁNY ÄAMAGES ×HATSOEVER ÒESULTING ÆROM ÌOSS ÏF ÕSE, ÄATA ÏR
PROFITS, ×HETHER ÉN ÁN ÁCTION ÏF ÃONTRACT, ÎEGLIGENCE ÏR ÏTHER
TORTIOUS ÁCTION, ÁRISING ÏUT ÏF ÏR ÉN ÃONNECTION ×ITH ÔHE ÕSE ÏR
PERFORMANCE ÏF ÔHIS ÄOCUMENTATION
Appendix Å. Âibliography
Table of Contents
Bibliography
Bibliography
[AeleenFrisch] Aeleen Frisch. Copyright 1991. O'Reilly & Associates.
Essential System Administration.
[CraigHunt] Craig Hunt. Copyright 1993. O'Reilly & Associates. TCP/IP Network
Administration.
[RFC1034] P. V. Mockapetris. Copyright 1987. RFC 1034: Domain names -
concepts and facilities.
[RFC1035] P. V. Mockapetris. Copyright 1987. RFC 1035: Domain names -
implementation and specification.
[RFC1055] J. L. Romkey. Copyright 1988. RFC 1055: Nonstandard for
transmission of IP datagrams over serial lines: SLIP.
[RFC1331] W. Simpson. Copyright 1992. RFC 1331: The Point-to-Point Protocol
(PPP) for the Transmission of Multi-protocol Datagrams over Point-to-Point
Links.
[RFC1332] G. McGregor. Copyright 1992. RFC 1332: The PPP Internet Protocol
Control Protocol (IPCP).
[RFC1933] R. Gilligan and E. Nordmark. Copyright 1996. RFC 1933: Transition
Mechanisms for IPv6 Hosts and Routers.
[RFC2004] C. Perkins. Copyright 1996. RFC 2003: IP Encapsulation within IP.
[RFC2401] S. Kent and R. Atkinson. Copyright 1998. RFC 2401: Security
Architecture for the Internet Protocol.
[RFC2411] R. Thayer, N. Doraswamy, and R. Glenn. Copyright 1998. RFC 2411: IP
Security Document Roadmap.
[RFC2461] T. Narten, E. Nordmark, and W. Simpson. Copyright 1998. RFC 2461:
Neighbor Discovery for IP Version 6 (IPv6).
[RFC2529] B. Carpenter and C. Jung. Copyright 1999. RFC 2529: Transmission of
IPv6 over IPv4 Domains without Explicit Tunnels.
[RFC3024] G. Montenegro. Copyright 2001. RFC 3024: Reverse Tunneling for
Mobile IP.
[RFC3027] M. Holdrege and P. Srisuresh. Copyright 2001. RFC 3027: Protocol
Complications with the IP Network Address Translator.
[RFC3056] B. Carpenter and K. Moore. Copyright 2001. RFC 3056: Connection of
IPv6 Domains via IPv4 Clouds.
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