<!-- $NetBSD: chap-rf.xml,v 1.19 2019/04/21 20:47:12 khorben Exp $ -->
<!-- I should have written this 2 years ago. With the import of Vinum
and recent enhancements to sysinst, this document may be depreciated
before I finish it. Hopefully it will be useful for the lifetime of
NetBSD 2.0 ~BAS/lava -->
<chapter id="chap-rf">
<title>NetBSD RAIDframe</title>
<sect1 id="chap-rf-intro">
<title>RAIDframe Introduction</title>
<sect2 id="chap-rf-intro-about">
<title>About RAIDframe</title>
<para>&os; uses the <ulink
url="http://www.pdl.cmu.edu/RAIDframe/">CMU RAIDframe</ulink>
software for its RAID subsystem. &os; is the primary
platform for RAIDframe development. RAIDframe can also be
found in OpenBSD and older
versions of FreeBSD. &os;
also has another in-kernel RAID level 0 system in its
&man.ccd.4; subsystem (see
<xref linkend="chap-ccd" />). You
should possess some <ulink
url="http://www.acnc.com/04_00.html">basic knowledge</ulink>
about RAID concepts and terminology before continuing. You
should also be at least familiar with the different levels of
RAID - Adaptec provides an <ulink
url="http://www.adaptec.com/en-US/_common/compatibility/_education/RAID_level_compar_wp.htm">
excellent reference</ulink>, and the &man.raid.4; manpage
contains a short overview too.</para>
</sect2>
<sect2 id="chap-rf-intro-warning">
<title>A warning about Data Integrity, Backups, and High
Availability </title>
<para>RAIDframe is a Software RAID implementation,
as opposed to Hardware RAID. As such, it does not need special disk
controllers supported by &os;. System
administrators should give a
great deal of consideration to whether software RAID or
hardware RAID is more appropriate for their
<quote>Mission Critical</quote> applications. For some projects
you might consider the use of many of the hardware RAID devices
<ulink url="http://www.NetBSD.org/support/hardware/">supported by
&os;</ulink>. 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.</para>
<para>Depending on the RAID level used, RAIDframe does provide
redundancy in the event of a hardware failure. However, it is
<emphasis>not</emphasis> 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.</para>
<para>Once more for good measure: <emphasis>Back up your
data!</emphasis></para>
</sect2>
<sect2 id="chap-rf-intro-gettingHelp">
<title>Getting Help</title>
<para>If you encounter problems using RAIDframe, you have several
options for obtaining help. </para>
<procedure>
<step>
<para>Read the RAIDframe man pages: &man.raid.4; and
&man.raidctl.8; thoroughly. </para>
</step>
<step>
<para>Search the mailing list archives. Unfortunately,
there is no &os; 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 <ulink
url="http://mail-index.NetBSD.org/netbsd-users/">netbsd-users@NetBSD.org</ulink>,
<ulink
url="http://mail-index.NetBSD.org/current-users/">current-users@NetBSD.org</ulink>.
Also search the list for the &os; platform on which you are
using RAIDframe:
port-<replaceable>${ARCH}</replaceable>@NetBSD.org.</para>
</step>
<step>
<para>Search the <ulink
url="http://www.NetBSD.org/support/send-pr.html">Problem Report
database</ulink>.</para>
</step>
<step>
<para>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
&man.dmesg.8; output from <filename>
/var/run/dmesg.boot</filename>, your kernel &man.config.5; , your
<filename>/etc/raid[0-9].conf</filename>, any relevant errors on
<filename>/dev/console</filename>,
<filename>/var/log/messages</filename>, or to
<filename>stdout/stderr</filename> of &man.raidctl.8;.
The output of <command>raidctl -s</command> (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.</para>
</step>
</procedure>
</sect2>
</sect1>
<sect1 id="chap-rf-initsetup">
<title>Setup RAIDframe Support</title>
<para>The use of RAID will require software and hardware
configuration changes.</para>
<sect2 id="chap-rf-init-kern">
<title>Kernel Support</title>
<para>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:</para>
<programlisting>pseudo-device raid 8 # RAIDframe disk driver
options RAID_AUTOCONFIG # auto-configuration of RAID components</programlisting>
<para>The RAID support must be detected by the &os; kernel, which
can be checked by looking at the output of the &man.dmesg.8;
command.</para>
<screen>&rprompt; <command>dmesg|grep -i raid</command>
Kernelized RAIDframe activated</screen>
<para>Historically, the kernel must also contain static mappings between bus
addresses and device nodes in <filename>/dev</filename>. This
used to
ensure consistency of devices within RAID sets in the event of a
device failure after reboot. Since &os; 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.</para>
</sect2>
<sect2 id="chap-rf-init-powercache">
<title>Power Redundancy and Disk Caching</title>
<para>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.</para>
<para>The &man.dkctl.8; utility can be used for this on
all kinds of disks that support the operation (SCSI, EIDE, SATA,
...):
</para>
<screen>
&rprompt; <command>dkctl <replaceable>wd0</replaceable> getcache</command>
/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
&rprompt; <command>dkctl <replaceable>wd0</replaceable> setcache rw</command>
&rprompt; <command>dkctl <replaceable>wd0</replaceable> getcache</command>
/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</screen>
</sect2>
</sect1>
<!-- Start beginning of tabbing audit here -->
<sect1 id="chap-rf-ex-raid1root">
<title>Example: RAID-1 Root Disk</title>
<para>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:</para>
<itemizedlist>
<listitem>
<para>Continue normal operations until a maintenance
window can be scheduled.</para>
</listitem>
<listitem>
<para>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).
</para>
</listitem>
</itemizedlist>
<figure id="RL1-DLD">
<title>RAID-1 Disk Logical Layout</title>
<mediaobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-raidL1-diskdia.eps" format="EPS" />
</imageobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-raidL1-diskdia.png" format="PNG" />
</imageobject>
</mediaobject>
</figure>
<para>Because RAID-1 provides both redundancy and performance
improvements, its most practical application is on critical
"system" partitions such as <filename>/</filename>,
<filename>/usr</filename>, <filename>/var</filename>,
<filename>swap</filename>, etc., where read operations are more
frequent than write operations. For other file systems, such as
<filename>/home</filename> or
<filename>/var/<replaceable>{application}</replaceable></filename>,
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. </para>
<note>
<para>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.</para>
</note>
<sect2 id="chap-rf-ex-raid1root-PPO">
<title>Pseudo-Process Outline </title>
<para>Although a much more refined process could be developed
using a custom copy of &os; installed on custom-developed
removable media, presently the &os; install media lacks
RAIDframe tools and support, so the following pseudo process has
become the de facto standard for setting up RAID-1 Root.</para>
<procedure>
<step>
<para>Install a stock &os; onto Disk0 of your system.</para>
<figure id="R1R-PP0-1">
<title>Perform generic install onto Disk0/wd0</title>
<mediaobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp1.eps" format="EPS" />
</imageobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp1.png" format="PNG" />
</imageobject>
</mediaobject>
</figure>
</step>
<step>
<para>Use the installed system on Disk0/wd0 to setup
a RAID Set composed of Disk1/wd1 only.</para>
<figure id="R1R-PP0-2">
<title>Setup RAID Set</title>
<mediaobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp2.eps" format="EPS" />
</imageobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp2.png" format="PNG" />
</imageobject>
</mediaobject>
</figure>
</step>
<step>
<para>Reboot the system off the Disk1/wd1 with the newly
created RAID volume. </para>
<figure id="R1R-PP0-3">
<title>Reboot using Disk1/wd1 of RAID</title>
<mediaobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp3.eps" format="EPS" />
</imageobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp3.png" format="PNG" />
</imageobject>
</mediaobject>
</figure>
</step>
<step>
<para>Add / re-sync Disk0/wd0 back into the RAID set.</para>
<figure id="R1R-PP0-4">
<title>Mirror Disk1/wd1 back to Disk0/wd0</title>
<mediaobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp4.eps" format="EPS" />
</imageobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-r1r-pp4.png" format="PNG" />
</imageobject>
</mediaobject>
</figure>
</step>
</procedure>
</sect2>
<sect2 id="chap-rf-ex-raid1root-hardware">
<title>Hardware Review</title>
<para>At present, the alpha, amd64, i386, pmax, sparc, sparc64, and
vax &os; 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.</para>
<para>This article assumes two identical
IDE disks (<devicename>/dev/wd<replaceable>{0,1}</replaceable></devicename>)
which we are going to mirror (RAID-1). These disks are identified
as:</para>
<screen>&rprompt; <command>grep ^wd /var/run/dmesg.boot</command>
<![CDATA[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)]]></screen>
<note>
<para>If you are using SCSI, replace
<filename>/dev/{,r}wd{0,1} </filename> with
<filename>/dev/{,r}sd{0,1}</filename></para>
</note>
<para>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.</para>
<note>
<para>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.</para>
</note>
<tip>
<para>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.</para>
</tip>
</sect2>
<sect2 id="chap-rf-install">
<title>Initial Install on Disk0/wd0</title>
<para>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
<xref linkend="chap-inst" />.</para>
<tip>
<para>On x86, during the sysinst install, when prompted if
you want to "use the entire disk for &os;", answer
"yes".</para>
</tip>
<para>Once the installation is complete, you should examine the
&man.disklabel.8; and &man.fdisk.8; / &man.sunlabel.8; outputs on
the system: </para>
<screen>&rprompt; <command>df</command>
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/wd0a 9487886 502132 8511360 5% /</screen>
<para>On x86:</para>
<screen>&rprompt; <command>disklabel -r wd0</command>
<![CDATA[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)
]]>
&rprompt; <command>fdisk /dev/rwd0d</command>
<![CDATA[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
]]></screen>
<para>On Sparc64 the command / output differs slightly: </para>
<screen>&rprompt; <command>disklabel -r wd0</command>
<![CDATA[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)
]]>
&rprompt; <command>sunlabel /dev/rwd0c</command>
<![CDATA[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)
]]></screen>
</sect2>
<sect2 id="chap-rf-second-disk">
<title>Preparing Disk1/wd1</title>
<para>Once you have a stock install of &os; 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 &man.disklabel.8; to
allocate the entire second disk to the RAID-1 set.</para>
<tip>
<para>The best way to ensure that Disk1/wd1 is completely
empty is to 'zero' out the first few sectors of the disk with
&man.dd.1; . This will erase the MBR (x86) or Sun disk label
(sparc64), as well as the &os; 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.</para>
</tip>
<note>
<para>On sparc64, use <filename>/dev/rwd1c</filename> instead of
<filename>/dev/rwd1d</filename>!</para>
</note>
<screen>&rprompt; <command>dd if=/dev/zero of=/dev/rwd1d bs=8k count=1</command>
1+0 records in
1+0 records out
8192 bytes transferred in 0.003 secs (2730666 bytes/sec)</screen>
<para>Once this is complete, on x86, verify that both the MBR and
&os; disk labels are gone. On sparc64, verify that the Sun Disk
label is gone as well.</para>
<para>On x86:</para>
<screen>&rprompt; <command>fdisk /dev/rwd1d</command>
<![CDATA[
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.
]]>
&rprompt; <command>disklabel -r wd1</command>
<![CDATA[
[...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)
]]></screen>
<para>On sparc64:</para>
<screen>&rprompt; <command>sunlabel /dev/rwd1c</command>
<![CDATA[
sunlabel: bogus label on `/dev/wd1c' (bad magic number)
]]>
&rprompt; <command>disklabel -r wd1</command>
<![CDATA[
[...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
]]></screen>
<para>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 &os;
partition active or the system will not boot. You must also create
a &os; disklabel on Disk1/wd1 that will enable a RAID volume to
exist upon it. On sparc64, you will need to simply
&man.disklabel.8; the second disk which will write the proper Sun
Disk Label.</para>
<tip>
<para>&man.disklabel.8; will use your shell' s environment
variable <varname>$EDITOR</varname> variable to edit the
disklabel. The default is &man.vi.1; </para>
</tip>
<para>On x86:</para>
<screen>&rprompt; <command>fdisk -0ua /dev/rwd1d</command>
<![CDATA[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
]]>
&rprompt; <command>disklabel -r -e -I wd1</command>
<![CDATA[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)
]]></screen>
<para>On sparc64:</para>
<screen>&rprompt; <command>disklabel -r -e -I wd1</command>
<![CDATA[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)
]]>
&rprompt; <command>sunlabel /dev/rwd1c </command>
<![CDATA[sunlabel> P
a: start cyl = 0, size = 19541088 (19386/0/0 - 9541.55Mb)
c: start cyl = 0, size = 19541088 (19386/0/0 - 9541.55Mb)
]]></screen>
<note>
<para>On x86, the <command>c:</command> and
<command>d:</command> slices are reserved. <command>c:</command>
represents the &os; portion of the disk. <command>d:</command>
represents the entire disk. Because we want to allocate the
entire &os; MBR partition to RAID, and because
<command>a:</command> resides within the bounds of
<command>c:</command>, the <command>a:</command> and
<command>c:</command> 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, <command>c:</command> represents the entire
&os; partition in the Sun disk label and <command>d:</command>
is not reserved. Also note that sparc64's <command>c:</command>
and <command>a:</command> 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).</para>
</note>
</sect2>
<sect2 id="chap-rf-configuring-raid">
<title>Initializing the RAID Device</title>
<para>Next we create the configuration file for the RAID set /
volume. Traditionally, RAIDframe configuration files belong in
<filename>/etc </filename> 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
<filename>/etc</filename>.</para>
<screen>&rprompt; <command>vi /var/tmp/raid0.conf</command>
START array
1 2 0
START disks
absent
/dev/wd1a
START layout
128 1 1 1
START queue
fifo 100</screen>
<para>Note that <filename>absent</filename> 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.</para>
<para>Next we configure the RAID device and initialize the serial
number to something unique. In this example we use a
"YYYYMMDD<replaceable>Revision</replaceable>" 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.</para>
<para>After that we initialize the RAID set for the first time,
safely ignoring the errors regarding the bogus component.</para>
<screen>&rprompt; <command>raidctl -v -C /var/tmp/raid0.conf raid0</command>
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)
&rprompt; <command>raidctl -v -I 2009122601 raid0</command>
&rprompt; <command>raidctl -v -i raid0</command>
Initiating re-write of parity
raid0: Error re-writing parity!
Parity Re-write status:
&rprompt; <command>tail -1 /var/log/messages</command>
Dec 26 00:00:30 /netbsd: raid0: Error re-writing parity!
&rprompt; <command>raidctl -v -s raid0</command>
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.</screen>
</sect2>
<sect2 id="chap-rf-setup-filesystems">
<title>Setting up Filesystems</title>
<caution>
<para>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.</para>
</caution>
<para>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 <filename>/</filename> as
<command>/dev/raid0a</command> and the rest allocated to
<filename>swap</filename> as
<command>/dev/raid0b</command>.</para>
<caution>
<para>This is an unrealistic disk layout for a production
server; the &os; Guide can expand on proper partitioning
technique. See <xref linkend="chap-inst" /></para>
</caution>
<note>
<para>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.</para>
</note>
<note>
<para>In our example, the space allocated to the underlying
<filename>a:</filename> slice composing the RAID set differed
between x86 and sparc64, therefore the total sectors of the RAID
volumes differs:</para>
</note>
<para>On x86:</para>
<screen> &rprompt; <command>disklabel -r -e -I raid0</command>
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*)</screen>
<para>On sparc64:</para>
<screen>&rprompt; <command>disklabel -r -e -I raid0</command>
[...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)</screen>
<para>Next, format the newly created <filename>/</filename>
partition as a 4.2BSD FFSv1 File System:</para>
<screen>&rprompt; <command>newfs -O 1 /dev/rraid0a</command>
/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,
...............................................................................
&rprompt; <command>fsck -fy /dev/rraid0a</command>
** /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)</screen>
</sect2>
<sect2 id="chap-rf-moving-files">
<title>Migrating System to RAID</title>
<para>The new RAID filesystems are now ready for use. We mount
them under <filename>/mnt</filename> and copy all files from the
old system. This can be done using &man.dump.8; or &man.pax.1;.</para>
<screen>&rprompt; <command>mount /dev/raid0a /mnt</command>
&rprompt; <command>df -h /mnt</command>
Filesystem Size Used Avail %Cap Mounted on
/dev/raid0a 8.9G 2.0K 8.5G 0% /mnt
&rprompt; <command>cd /; pax -v -X -rw -pe . /mnt</command>
[...snip...]</screen>
<para>The &os; install now exists on the RAID filesystem. We need
to fix the mount-points in the new copy of
<filename>/etc/fstab</filename> or the system will not come up
correctly. Replace instances of <filename>wd0</filename> with
<filename>raid0</filename>.</para>
<para>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 <filename>/etc/rc.conf</filename>.</para>
<screen>&rprompt; <command>vi /mnt/etc/rc.conf</command>
swapoff=YES</screen>
<para>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.</para>
<tip>
<para>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.</para>
</tip>
<caution>
<para>Although it may seem logical to install the 1st stage boot block into
<filename>/dev/rwd1<replaceable>{c,d}</replaceable></filename>
with &man.installboot.8; , this is no longer the case since &os; 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.</para>
</caution>
<para>On x86, install the boot loader into <filename>/dev/rwd1a
</filename>:</para>
<screen>&rprompt; <command>/usr/sbin/installboot -o timeout=30 -v /dev/rwd1a /usr/mdec/bootxx_ffsv2</command>
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</screen>
<note>
<para>As of &os; 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
<filename>/usr/mdec/bootxx_ffsv<replaceable>{1,2}</replaceable></filename>
when running the &man.installboot.8; command.</para>
<para>To find out which filesystem type is currently in use, the
command &man.file.1; or &man.dumpfs.8; can be used:</para>
<screen>&rprompt; <command>/usr/bin/file -s /dev/rwd1a</command>
/usr/bin/file -s /dev/rwd1a
/dev/rwd1a: Unix Fast File system [v2] (little-endian), last mounted on ...</screen>
<para>or</para>
<screen>&rprompt; <command>/usr/sbin/dumpfs -s /dev/rwd1a</command>
file system: /dev/rwd1a
format FFSv2
endian little-endian
...</screen>
</note>
<para>On sparc64, install the boot loader into
<filename>/dev/rwd1a </filename> as well, however the "-o" flag is
unsupported (and un-needed thanks to OpenBoot):</para>
<screen>&rprompt; <command>/usr/sbin/installboot -v /dev/rwd1a /usr/mdec/bootblk</command>
File system: /dev/rwd1a
Primary bootstrap: /usr/mdec/bootblk
Bootstrap start sector: 1
Bootstrap byte count: 5140
Writing bootstrap</screen>
<para>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.</para>
<screen>&rprompt; <command>raidctl -v -A root raid0</command>
raid0: Autoconfigure: Yes
raid0: Root: Yes
&rprompt; <command>tail -2 /var/log/messages</command>
raid0: New autoconfig value is: 1
raid0: New rootpartition value is: 1
&rprompt; <command>raidctl -v -s raid0</command>
[...snip...]
Autoconfig: Yes
Root partition: Yes
Last configured as: raid0
[...snip...]
&rprompt; <command>shutdown -r now</command></screen>
<warning>
<para>Always use &man.shutdown.8; when shutting
down. Never simply use &man.reboot.8;. &man.reboot.8; will
not properly run shutdown RC scripts and will not safely disable
swap. This will cause dirty parity at every
reboot.</para>
</warning>
</sect2>
<sect2 id="chap-rf-boot-with-raid1">
<title>The first boot with RAID</title>
<para>At this point, temporarily configure your system to boot
Disk1/wd1. See notes in
<xref linkend="chap-rf-adding-test-boot" />
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.</para>
<screen>&rprompt; <command>egrep -i "raid|root" /var/run/dmesg.boot</command>
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
&rprompt; <command>df -h</command>
Filesystem Size Used Avail Capacity Mounted on
/dev/raid0a 8.9G 196M 8.3G 2% /
kernfs 1.0K 1.0K 0B 100% /kern
&rprompt; <command>swapctl -l</command>
Device 1K-blocks Used Avail Capacity Priority
/dev/raid0b 262592 0 262592 0% 0
&rprompt; <command>raidctl -s raid0</command>
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.</screen>
</sect2>
<sect2 id="chap-rf-adding-first-disk">
<title>Adding Disk0/wd0 to RAID</title>
<para>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 &os; 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.</para>
<screen>&rprompt; <command>disklabel -r wd1 > /tmp/disklabel.wd1</command>
&rprompt; <command>disklabel -R -r wd0 /tmp/disklabel.wd1</command></screen>
<para>As a last-minute sanity check, you might want to use
&man.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.</para>
<screen>&rprompt; <command>disklabel -r wd0 > /tmp/disklabel.wd0</command>
&rprompt; <command>disklabel -r wd1 > /tmp/disklabel.wd1</command>
&rprompt; <command>diff /tmp/disklabel.wd0 /tmp/disklabel.wd1</command>
&rprompt; <command>fdisk /dev/rwd0 > /tmp/fdisk.wd0</command>
&rprompt; <command>fdisk /dev/rwd1 > /tmp/fdisk.wd1</command>
&rprompt; <command>diff /tmp/fdisk.wd0 /tmp/fdisk.wd1</command>
&rprompt; <command>mkdir /root/RFbackup</command>
&rprompt; <command>cp -p /tmp/{disklabel,fdisk}* /root/RFbackup</command></screen>
<para>Once you are certain, add Disk0/wd0 as a spare
component, and start reconstruction:</para>
<screen>&rprompt; <command>raidctl -v -a /dev/wd0a raid0</command>
/netbsd: Warning: truncating spare disk /dev/wd0a to 241254528 blocks
&rprompt; <command>raidctl -v -s raid0</command>
Components:
component0: failed
/dev/wd1a: optimal
Spares:
/dev/wd0a: spare
[...snip...]
&rprompt; <command>raidctl -F component0 raid0</command>
RECON: initiating reconstruction on col 0 -> spare at col 2
11% |**** | ETA: 04:26 \</screen>
<para>Depending on the speed of your hardware, the reconstruction
time will vary. You may wish to watch it on another
terminal:</para>
<screen>&rprompt; <command>raidctl -S raid0</command>
Reconstruction is 0% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.
Reconstruction status:
17% |****** | ETA: 03:08 -</screen>
<para>After reconstruction, both disks should be
<quote>optimal</quote>.</para>
<screen>&rprompt; <command>tail -f /var/log/messages</command>
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
&rprompt; <command>raidctl -v -s raid0</command>
Components:
component0: spared
/dev/wd1a: optimal
Spares:
/dev/wd0a: used_spare
[...snip...]</screen>
<para>When the reconstruction is finished we need to install the
boot loader on the Disk0/wd0. On x86, install the boot loader
into <filename>/dev/rwd0a</filename>:</para>
<screen>&rprompt; <command>/usr/sbin/installboot -o timeout=15 -v /dev/rwd0a /usr/mdec/bootxx_ffsv2</command>
File system: /dev/rwd0a
Primary bootstrap: /usr/mdec/bootxx_ffsv2
Boot options: timeout 15, flags 0, speed 9600, ioaddr 0, console pc</screen>
<para>On sparc64:</para>
<screen>&rprompt; <command>/usr/sbin/installboot -v /dev/rwd0a /usr/mdec/bootblk</command>
File system: /dev/rwd0a
Primary bootstrap: /usr/mdec/bootblk
Bootstrap start sector: 1
Bootstrap byte count: 5140
Writing bootstrap</screen>
<para>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.</para>
<screen>&rprompt; <command>shutdown -r now</command></screen>
</sect2>
<sect2 id="chap-rf-adding-test-boot">
<title>Testing Boot Blocks</title>
<para>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.</para>
<para>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.</para>
<figure id="Award-BIOS-2">
<title>Award BIOS i386 Boot Disk1/wd1</title>
<mediaobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-awardbios2.eps" format="EPS" />
</imageobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-awardbios2.png" format="PNG" />
</imageobject>
</mediaobject>
</figure>
<para>Save changes and exit.</para>
<screen>>> 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</screen>
<para>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:</para>
<figure id="Award-BIOS-1">
<title>Award BIOS i386 Boot Disk0/wd0</title>
<mediaobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-awardbios1.eps" format="EPS" />
</imageobject>
<imageobject>
<imagedata fileref="&imagesdir;/rf-awardbios1.png" format="PNG" />
</imageobject>
</mediaobject>
</figure>
<para>Save changes and exit.</para>
<screen>>> 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.
</screen>
<para>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.</para>
<para>On sparc64, use the Sun OpenBoot <command>devalias</command>
to confirm that both disks are bootable:</para>
<screen>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.
<command>ok devalias</command>
[...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...]
<command>ok boot disk0 netbsd</command>
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...]</screen>
<para>And the second disk:</para>
<screen><command>ok boot disk2 netbsd</command>
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...]</screen>
<para>At each boot, the following should appear in the &os;
kernel &man.dmesg.8; :</para>
<screen>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</screen>
<para>Once you are certain that both disks are bootable, verify
the RAID parity is clean after each reboot:</para>
<screen>&rprompt; <command>raidctl -v -s raid0</command>
Components:<emphasis><command>
/dev/wd0a: optimal
/dev/wd1a: optimal</command></emphasis>
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
<emphasis><command>Parity status: clean</command></emphasis>
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.</screen>
</sect2>
</sect1>
</chapter>