10b0b0a21e
most of the other spurious comments. Two comments relating to copyright have *not* been merged in from the LinuxDoc version yet -- I've contacted the original authors to ask if they would be willing to assign the copyright to the project. When I get their response the copyright comments will either be merged in, or left out, as necessary.
621 lines
24 KiB
Text
621 lines
24 KiB
Text
<!--
|
|
The FreeBSD Documentation Project
|
|
|
|
$Id: chapter.sgml,v 1.6 1999-03-08 22:04:36 nik Exp $
|
|
-->
|
|
|
|
<chapter id="backups">
|
|
<title>Backups</title>
|
|
|
|
<para>Issues of hardware compatibility are among the most troublesome in the
|
|
computer industry today and FreeBSD is by no means immune to trouble. In
|
|
this respect, FreeBSD's advantage of being able to run on inexpensive
|
|
commodity PC hardware is also its liability when it comes to support for
|
|
the amazing variety of components on the market. While it would be
|
|
impossible to provide a exhaustive listing of hardware that FreeBSD
|
|
supports, this section serves as a catalog of the device drivers included
|
|
with FreeBSD and the hardware each drivers supports. Where possible and
|
|
appropriate, notes about specific products are included. You may also
|
|
want to refer to <link linkend="kernelconfig-config"> the kernel
|
|
configuration file</link> section in this handbook for a list of
|
|
supported devices.</para>
|
|
|
|
<para>As FreeBSD is a volunteer project without a funded testing department,
|
|
we depend on you, the user, for much of the information contained in this
|
|
catalog. If you have direct experience of hardware that does or does not
|
|
work with FreeBSD, please let us know by sending e-mail to the &a.doc;.
|
|
Questions about supported hardware should be directed to the &a.questions
|
|
(see <link linkend="eresources-mail">Mailing Lists</link> for more
|
|
information). When submitting information or asking a question, please
|
|
remember to specify exactly what version of FreeBSD you are using and
|
|
include as many details of your hardware as possible.</para>
|
|
|
|
<sect1>
|
|
<title>* What about backups to floppies?</title>
|
|
|
|
<para></para>
|
|
</sect1>
|
|
|
|
<sect1 id="backups-tapebackups">
|
|
<title>Tape Media</title>
|
|
|
|
<para>The major tape media are the 4mm, 8mm, QIC, mini-cartridge and
|
|
DLT.</para>
|
|
|
|
<sect2 id="backups-tapebackups-4mm">
|
|
<title>4mm (DDS: Digital Data Storage)</title>
|
|
|
|
<para>4mm tapes are replacing QIC as the workstation backup media of
|
|
choice. This trend accelerated greatly when Conner purchased Archive,
|
|
a leading manufacturer of QIC drives, and then stopped production of
|
|
QIC drives. 4mm drives are small and quiet but do not have the
|
|
reputation for reliability that is enjoyed by 8mm drives. The
|
|
cartridges are less expensive and smaller (3 x 2 x 0.5 inches, 76 x 51
|
|
x 12 mm) than 8mm cartridges. 4mm, like 8mm, has comparatively short
|
|
head life for the same reason, both use helical scan.</para>
|
|
|
|
<para>Data thruput on these drives starts ~150kB/s, peaking at ~500kB/s.
|
|
Data capacity starts at 1.3 GB and ends at 2.0 GB. Hardware
|
|
compression, available with most of these drives, approximately
|
|
doubles the capacity. Multi-drive tape library units can have 6
|
|
drives in a single cabinet with automatic tape changing. Library
|
|
capacities reach 240 GB.</para>
|
|
|
|
<para>4mm drives, like 8mm drives, use helical-scan. All the benefits
|
|
and drawbacks of helical-scan apply to both 4mm and 8mm drives.</para>
|
|
|
|
<para>Tapes should be retired from use after 2,000 passes or 100 full
|
|
backups.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="backups-tapebackups-8mm">
|
|
<title>8mm (Exabyte)</title>
|
|
|
|
<para>8mm tapes are the most common SCSI tape drives; they are the best
|
|
choice of exchanging tapes. Nearly every site has an exabyte 2 GB 8mm
|
|
tape drive. 8mm drives are reliable, convenient and quiet. Cartridges
|
|
are inexpensive and small (4.8 x 3.3 x 0.6 inches; 122 x 84 x 15 mm).
|
|
One downside of 8mm tape is relatively short head and tape life due to
|
|
the high rate of relative motion of the tape across the heads.</para>
|
|
|
|
<para>Data thruput ranges from ~250kB/s to ~500kB/s. Data sizes start
|
|
at 300 MB and go up to 7 GB. Hardware compression, available with
|
|
most of these drives, approximately doubles the capacity. These
|
|
drives are available as single units or multi-drive tape libraries
|
|
with 6 drives and 120 tapes in a single cabinet. Tapes are changed
|
|
automatically by the unit. Library capacities reach 840+ GB.</para>
|
|
|
|
<para>Data is recorded onto the tape using helical-scan, the heads are
|
|
positioned at an angle to the media (approximately 6 degrees). The
|
|
tape wraps around 270 degrees of the spool that holds the heads. The
|
|
spool spins while the tape slides over the spool. The result is a
|
|
high density of data and closely packed tracks that angle across the
|
|
tape from one edge to the other.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="backups-tapebackups-qic">
|
|
<title>QIC</title>
|
|
|
|
<para>QIC-150 tapes and drives are, perhaps, the most common tape drive
|
|
and media around. QIC tape drives are the least expensive "serious"
|
|
backup drives. The downside is the cost of media. QIC tapes are
|
|
expensive compared to 8mm or 4mm tapes, up to 5 times the price per GB
|
|
data storage. But, if your needs can be satisfied with a half-dozen
|
|
tapes, QIC may be the correct choice. QIC is the
|
|
<emphasis>most</emphasis> common tape drive. Every site has a QIC
|
|
drive of some density or another. Therein lies the rub, QIC has a
|
|
large number of densities on physically similar (sometimes identical)
|
|
tapes. QIC drives are not quiet. These drives audibly seek before
|
|
they begin to record data and are clearly audible whenever reading,
|
|
writing or seeking. QIC tapes measure (6 x 4 x 0.7 inches; 15.2 x
|
|
10.2 x 1.7 mm). <link
|
|
linkend="backups-tapebackups-mini">Mini-cartridges</link>, which
|
|
also use 1/4" wide tape are discussed separately. Tape libraries and
|
|
changers are not available.</para>
|
|
|
|
<para>Data thruput ranges from ~150kB/s to ~500kB/s. Data capacity
|
|
ranges from 40 MB to 15 GB. Hardware compression is available on many
|
|
of the newer QIC drives. QIC drives are less frequently installed;
|
|
they are being supplanted by DAT drives.</para>
|
|
|
|
<para>Data is recorded onto the tape in tracks. The tracks run along
|
|
the long axis of the tape media from one end to the other. The number
|
|
of tracks, and therefore the width of a track, varies with the tape's
|
|
capacity. Most if not all newer drives provide backward-compatibility
|
|
at least for reading (but often also for writing). QIC has a good
|
|
reputation regarding the safety of the data (the mechanics are simpler
|
|
and more robust than for helical scan drives).</para>
|
|
|
|
<para>Tapes should be retired from use after 5,000 backups.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="backups-tapebackups-mini">
|
|
<title>* Mini-Cartridge</title>
|
|
|
|
<para></para>
|
|
</sect2>
|
|
|
|
<sect2 id="backups-tapebackups-dlt">
|
|
<title>DLT</title>
|
|
|
|
<para>DLT has the fastest data transfer rate of all the drive types
|
|
listed here. The 1/2" (12.5mm) tape is contained in a single spool
|
|
cartridge (4 x 4 x 1 inches; 100 x 100 x 25 mm). The cartridge has a
|
|
swinging gate along one entire side of the cartridge. The drive
|
|
mechanism opens this gate to extract the tape leader. The tape leader
|
|
has an oval hole in it which the drive uses to "hook" the tape. The
|
|
take-up spool is located inside the tape drive. All the other tape
|
|
cartridges listed here (9 track tapes are the only exception) have
|
|
both the supply and take-up spools located inside the tape cartridge
|
|
itself.</para>
|
|
|
|
<para>Data thruput is approximately 1.5MB/s, three times the thruput of
|
|
4mm, 8mm, or QIC tape drives. Data capacities range from 10GB to 20GB
|
|
for a single drive. Drives are available in both multi-tape changers
|
|
and multi-tape, multi-drive tape libraries containing from 5 to 900
|
|
tapes over 1 to 20 drives, providing from 50GB to 9TB of
|
|
storage.</para>
|
|
|
|
<para>Data is recorded onto the tape in tracks parallel to the direction
|
|
of travel (just like QIC tapes). Two tracks are written at once.
|
|
Read/write head lifetimes are relatively long; once the tape stops
|
|
moving, there is no relative motion between the heads and the
|
|
tape.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Using a new tape for the first time</title>
|
|
|
|
<para>The first time that you try to read or write a new, completely
|
|
blank tape, the operation will fail. The console messages should be
|
|
similar to:</para>
|
|
|
|
<screen>st0(ncr1:4:0): NOT READY asc:4,1
|
|
st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|
|
|
<para>The tape does not contain an Identifier Block (block number 0).
|
|
All QIC tape drives since the adoption of QIC-525 standard write an
|
|
Identifier Block to the tape. There are two solutions:</para>
|
|
|
|
<para><command>mt fsf 1</command> causes the tape drive to write an
|
|
Identifier Block to the tape.</para>
|
|
|
|
<para>Use the front panel button to eject the tape.</para>
|
|
|
|
<para>Re-insert the tape and &man.dump.8; data to the tape.</para>
|
|
|
|
<para>&man.dump.8; will report <literal>DUMP: End of tape
|
|
detected</literal> and the console will show: <literal>HARDWARE
|
|
FAILURE info:280 asc:80,96</literal></para>
|
|
|
|
<para>rewind the tape using: <command>mt rewind</command></para>
|
|
|
|
<para>Subsequent tape operations are successful.</para>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="backup-programs">
|
|
<title>Backup Programs</title>
|
|
|
|
<para>The three major programs are
|
|
&man.dump.8;,
|
|
&man.tar.1;,
|
|
and
|
|
&man.cpio.1;.</para>
|
|
|
|
<sect2>
|
|
<title>Dump and Restore</title>
|
|
|
|
<para>&man.dump.8; and &man.restore.8; are the traditional Unix backup
|
|
programs. They operate on the drive as a collection of disk blocks,
|
|
below the abstractions of files, links and directories that are
|
|
created by the filesystems. &man.dump.8; backs up devices, entire
|
|
filesystems, not parts of a filesystem and not directory trees that
|
|
span more than one filesystem, using either soft links &man.ln.1; or
|
|
mounting one filesystem onto another. &man.dump.8; does not write
|
|
files and directories to tape, but rather writes the data blocks that
|
|
are the building blocks of files and directories. &man.dump.8; has
|
|
quirks that remain from its early days in Version 6 of ATT Unix (circa
|
|
1975). The default parameters are suitable for 9-track tapes (6250
|
|
bpi), not the high-density media available today (up to 62,182 ftpi).
|
|
These defaults must be overridden on the command line to utilize the
|
|
capacity of current tape drives.</para>
|
|
|
|
<para>&man.rdump.8; and &man.rrestore.8; backup data across the network
|
|
to a tape drive attached to another computer. Both programs rely upon
|
|
&man.rcmd.3; and &man.ruserok.3; to access the remote tape drive.
|
|
Therefore, the user performing the backup must have
|
|
<literal>rhosts</literal> access to the remote computer. The
|
|
arguments to &man.rdump.8; and &man.rrestore.8; must suitable to use
|
|
on the remote computer. (e.g. When <command>rdump</command>'ing from
|
|
a FreeBSD computer to an Exabyte tape drive connected to a Sun called
|
|
<hostid>komodo</hostid>, use: <command>/sbin/rdump 0dsbfu 54000 13000
|
|
126 komodo:/dev/nrst8 /dev/rsd0a 2>&1</command>) Beware: there
|
|
are security implications to allowing <literal>rhosts</literal>
|
|
commands. Evaluate your situation carefully.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Tar</title>
|
|
|
|
<para>&man.tar.1; also dates back to Version 6 of ATT Unix (circa 1975).
|
|
&man.tar.1; operates in cooperation with the filesystem; &man.tar.1;
|
|
writes files and directories to tape. &man.tar.1; does not support the
|
|
full range of options that are available from &man.cpio.1;, but
|
|
&man.tar.1; does not require the unusual command pipeline that
|
|
&man.cpio.1; uses.</para>
|
|
|
|
<para>Most versions of &man.tar.1; do not support backups across the
|
|
network. The GNU version of &man.tar.1;, which FreeBSD utilizes,
|
|
supports remote devices using the same syntax as &man.rdump.8;. To
|
|
&man.tar.1; to an Exabyte tape drive connected to a Sun called
|
|
<hostid>komodo</hostid>, use: <command>/usr/bin/tar cf
|
|
komodo:/dev/nrst8 . 2>&1</command>. For versions without remote
|
|
device support, you can use a pipeline and &man.rsh.1; to send the
|
|
data to a remote tape drive. (XXX add an example command)</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Cpio</title>
|
|
|
|
<para>&man.cpio.1; is the original Unix file interchange tape program
|
|
for magnetic media. &man.cpio.1; has options (among many others) to
|
|
perform byte-swapping, write a number of different archives format,
|
|
and pipe the data to other programs. This last feature makes
|
|
&man.cpio.1; and excellent choice for installation media.
|
|
&man.cpio.1; does not know how to walk the directory tree and a list
|
|
of files must be provided thru <filename>STDIN</filename>.</para>
|
|
|
|
<para>&man.cpio.1; does not support backups across the network. You can
|
|
use a pipeline and &man.rsh.1; to send the data to a remote tape
|
|
drive. (XXX add an example command)</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Pax</title>
|
|
|
|
<para>&man.pax.1; is IEEE/POSIX's answer to &man.tar.1; and
|
|
&man.cpio.1;. Over the years the various versions of &man.tar.1;
|
|
and &man.cpio.1; have gotten slightly incompatible. So rather than
|
|
fight it out to fully standardize them, POSIX created a new archive
|
|
utility. &man.pax.1; attempts to read and write many of the various
|
|
&man.cpio.1; and &man.tar.1; formats, plus new formats of its own.
|
|
Its command set more resembles &man.cpio.1; than &man.tar.1;.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="backups-programs-amanda">
|
|
<title>Amanda</title>
|
|
|
|
<para><ulink url="../ports/misc.html#amanda-2.4.0">Amanda</ulink>
|
|
(Advanced Maryland Network Disk Archiver) is a client/server backup
|
|
system, rather than a single program. An Amanda server will backup to
|
|
a single tape drive any number of computers that have Amanda clients
|
|
and network communications with the Amanda server. A common problem
|
|
at locations with a number of large disks is the length of time
|
|
required to backup to data directly to tape exceeds the amount of time
|
|
available for the task. Amanda solves this problem. Amanda can use a
|
|
"holding disk" to backup several filesystems at the same time. Amanda
|
|
creates "archive sets": a group of tapes used over a period of time to
|
|
create full backups of all the filesystems listed in Amanda's
|
|
configuration file. The "archive set" also contains nightly
|
|
incremental (or differential) backups of all the filesystems.
|
|
Restoring a damaged filesystem requires the most recent full backup
|
|
and the incremental backups.</para>
|
|
|
|
<para>The configuration file provides fine control backups and the
|
|
network traffic that Amanda generates. Amanda will use any of the
|
|
above backup programs to write the data to tape. Amanda is available
|
|
as either a port or a package, it is not installed by default.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Do nothing</title>
|
|
|
|
<para>“Do nothing” is not a computer program, but it is the
|
|
most widely used backup strategy. There are no initial costs. There
|
|
is no backup schedule to follow. Just say no. If something happens
|
|
to your data, grin and bear it!</para>
|
|
|
|
<para>If your time and your data is worth little to nothing, then
|
|
“Do nothing” is the most suitable backup program for your
|
|
computer. But beware, Unix is a useful tool, you may find that within
|
|
six months you have a collection of files that are valuable to
|
|
you.</para>
|
|
|
|
<para>“Do nothing” is the correct backup method for
|
|
<filename>/usr/obj</filename> and other directory trees that can be
|
|
exactly recreated by your computer. An example is the files that
|
|
comprise these handbook pages-they have been generated from
|
|
<acronym>SGML</acronym> input files. Creating backups of these
|
|
<acronym>HTML</acronym> files is not necessary. The
|
|
<acronym>SGML</acronym> source files are backed up regularly.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Which Backup Program is Best?</title>
|
|
|
|
<para>&man.dump.8; <emphasis>Period.</emphasis> Elizabeth D. Zwicky
|
|
torture tested all the backup programs discussed here. The clear
|
|
choice for preserving all your data and all the peculiarities of Unix
|
|
filesystems is &man.dump.8;. Elizabeth created filesystems containing
|
|
a large variety of unusual conditions (and some not so unusual ones)
|
|
and tested each program by do a backup and restore of that
|
|
filesystems. The peculiarities included: files with holes, files with
|
|
holes and a block of nulls, files with funny characters in their
|
|
names, unreadable and unwritable files, devices, files that change
|
|
size during the backup, files that are created/deleted during the
|
|
backup and more. She presented the results at LISA V in Oct. 1991.
|
|
See <ulink
|
|
url="http://reality.sgi.com/zwicky_neu/testdump.doc.html">torture-testing
|
|
Backup and Archive Programs</ulink>.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Emergency Restore Procedure</title>
|
|
|
|
<sect3>
|
|
<title>Before the Disaster</title>
|
|
|
|
<para>There are only four steps that you need to perform in
|
|
preparation for any disaster that may occur.</para>
|
|
|
|
<para>First, print the disklabel from each of your disks
|
|
(<command>e.g. disklabel sd0 | lpr</command>), your filesystem table
|
|
(<command>/etc/fstab</command>) and all boot messages, two copies of
|
|
each.</para>
|
|
|
|
<para>Second, determine that the boot and fixit floppies
|
|
(<filename>boot.flp</filename> and <filename>fixit.flp</filename>)
|
|
have all your devices. The easiest way to check is to reboot your
|
|
machine with the boot floppy in the floppy drive and check the boot
|
|
messages. If all your devices are listed and functional, skip on to
|
|
step three.</para>
|
|
|
|
<para>Otherwise, you have to create two custom bootable floppies which
|
|
has a kernel that can mount your all of your disks and access your
|
|
tape drive. These floppies must contain:
|
|
&man.fdisk.8;, &man.disklabel.8;, &man.newfs.8;, &man.mount.8;, and
|
|
whichever backup program you use. These programs must be statically
|
|
linked. If you use &man.dump.8;, the floppy must contain
|
|
&man.restore.8;.</para>
|
|
|
|
<para>Third, create backup tapes regularly. Any changes that you make
|
|
after your last backup may be irretrievably lost. Write-protect the
|
|
backup tapes.</para>
|
|
|
|
<para>Fourth, test the floppies (either <filename>boot.flp</filename>
|
|
and <filename>fixit.flp</filename> or the two custom bootable
|
|
floppies you made in step two.) and backup tapes. Make notes of the
|
|
procedure. Store these notes with the bootable floppy, the
|
|
printouts and the backup tapes. You will be so distraught when
|
|
restoring that the notes may prevent you from destroying your backup
|
|
tapes (How? In place of <command>tar xvf /dev/rst0</command>, you
|
|
might accidently type <command>tar cvf /dev/rst0</command> and
|
|
over-write your backup tape).</para>
|
|
|
|
<para>For an added measure of security, make bootable floppies and two
|
|
backup tapes each time. Store one of each at a remote location. A
|
|
remote location is NOT the basement of the same office building. A
|
|
number of firms in the World Trade Center learned this lesson the
|
|
hard way. A remote location should be physically separated from
|
|
your computers and disk drives by a significant distance.</para>
|
|
|
|
<para>An example script for creating a bootable floppy:</para>
|
|
|
|
<programlisting>
|
|
<![ CDATA [#!/bin/sh
|
|
#
|
|
# create a restore floppy
|
|
#
|
|
# format the floppy
|
|
#
|
|
PATH=/bin:/sbin:/usr/sbin:/usr/bin
|
|
|
|
fdformat -q fd0
|
|
if [ $? -ne 0 ]
|
|
then
|
|
echo "Bad floppy, please use a new one"
|
|
exit 1
|
|
fi
|
|
|
|
# place boot blocks on the floppy
|
|
#
|
|
disklabel -w -B -b /usr/mdec/fdboot -s /usr/mdec/bootfd /dev/rfd0c fd1440
|
|
|
|
#
|
|
# newfs the one and only partition
|
|
#
|
|
newfs -t 2 -u 18 -l 1 -c 40 -i 5120 -m 5 -o space /dev/rfd0a
|
|
|
|
#
|
|
# mount the new floppy
|
|
#
|
|
mount /dev/fd0a /mnt
|
|
|
|
#
|
|
# create required directories
|
|
#
|
|
mkdir /mnt/dev
|
|
mkdir /mnt/bin
|
|
mkdir /mnt/sbin
|
|
mkdir /mnt/etc
|
|
mkdir /mnt/root
|
|
mkdir /mnt/mnt # for the root partition
|
|
mkdir /mnt/tmp
|
|
mkdir /mnt/var
|
|
|
|
#
|
|
# populate the directories
|
|
#
|
|
if [ ! -x /sys/compile/MINI/kernel ]
|
|
then
|
|
cat << EOM
|
|
The MINI kernel does not exist, please create one.
|
|
Here is an example config file:
|
|
#
|
|
# MINI -- A kernel to get FreeBSD on onto a disk.
|
|
#
|
|
machine "i386"
|
|
cpu "I486_CPU"
|
|
ident MINI
|
|
maxusers 5
|
|
|
|
options INET # needed for _tcp _icmpstat _ipstat
|
|
# _udpstat _tcpstat _udb
|
|
options FFS #Berkeley Fast File System
|
|
options FAT_CURSOR #block cursor in syscons or pccons
|
|
options SCSI_DELAY=15 #Be pessimistic about Joe SCSI device
|
|
options NCONS=2 #1 virtual consoles
|
|
options USERCONFIG #Allow user configuration with -c XXX
|
|
|
|
config kernel root on sd0 swap on sd0 and sd1 dumps on sd0
|
|
|
|
controller isa0
|
|
controller pci0
|
|
|
|
controller fdc0 at isa? port "IO_FD1" bio irq 6 drq 2 vector fdintr
|
|
disk fd0 at fdc0 drive 0
|
|
|
|
controller ncr0
|
|
|
|
controller scbus0
|
|
|
|
device sc0 at isa? port "IO_KBD" tty irq 1 vector scintr
|
|
device npx0 at isa? port "IO_NPX" irq 13 vector npxintr
|
|
|
|
device sd0
|
|
device sd1
|
|
device sd2
|
|
|
|
device st0
|
|
|
|
pseudo-device loop # required by INET
|
|
pseudo-device gzip # Exec gzipped a.out's
|
|
EOM
|
|
exit 1
|
|
fi
|
|
|
|
cp -f /sys/compile/MINI/kernel /mnt
|
|
|
|
gzip -c -best /sbin/init > /mnt/sbin/init
|
|
gzip -c -best /sbin/fsck > /mnt/sbin/fsck
|
|
gzip -c -best /sbin/mount > /mnt/sbin/mount
|
|
gzip -c -best /sbin/halt > /mnt/sbin/halt
|
|
gzip -c -best /sbin/restore > /mnt/sbin/restore
|
|
|
|
gzip -c -best /bin/sh > /mnt/bin/sh
|
|
gzip -c -best /bin/sync > /mnt/bin/sync
|
|
|
|
cp /root/.profile /mnt/root
|
|
|
|
cp -f /dev/MAKEDEV /mnt/dev
|
|
chmod 755 /mnt/dev/MAKEDEV
|
|
|
|
chmod 500 /mnt/sbin/init
|
|
chmod 555 /mnt/sbin/fsck /mnt/sbin/mount /mnt/sbin/halt
|
|
chmod 555 /mnt/bin/sh /mnt/bin/sync
|
|
chmod 6555 /mnt/sbin/restore
|
|
|
|
#
|
|
# create the devices nodes
|
|
#
|
|
cd /mnt/dev
|
|
./MAKEDEV std
|
|
./MAKEDEV sd0
|
|
./MAKEDEV sd1
|
|
./MAKEDEV sd2
|
|
./MAKEDEV st0
|
|
./MAKEDEV pty0
|
|
cd /
|
|
|
|
#
|
|
# create minimum filesystem table
|
|
#
|
|
cat > /mnt/etc/fstab <<EOM
|
|
/dev/fd0a / ufs rw 1 1
|
|
EOM
|
|
|
|
#
|
|
# create minimum passwd file
|
|
#
|
|
cat > /mnt/etc/passwd <<EOM
|
|
root:*:0:0:Charlie &:/root:/bin/sh
|
|
EOM
|
|
|
|
cat > /mnt/etc/master.passwd <<EOM
|
|
root::0:0::0:0:Charlie &:/root:/bin/sh
|
|
EOM
|
|
|
|
chmod 600 /mnt/etc/master.passwd
|
|
chmod 644 /mnt/etc/passwd
|
|
/usr/sbin/pwd_mkdb -d/mnt/etc /mnt/etc/master.passwd
|
|
|
|
#
|
|
# umount the floppy and inform the user
|
|
#
|
|
/sbin/umount /mnt]]></programlisting>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>After the Disaster</title>
|
|
|
|
<para>The key question is: did your hardware survive? You have been
|
|
doing regular backups so there is no need to worry about the
|
|
software.</para>
|
|
|
|
<para>If the hardware has been damaged. First, replace those parts
|
|
that have been damaged.</para>
|
|
|
|
<para>If your hardware is okay, check your floppies. If you are using
|
|
a custom boot floppy, boot single-user (type <literal>-s</literal>
|
|
at the <prompt>boot:</prompt> prompt). Skip the following
|
|
paragraph.</para>
|
|
|
|
<para>If you are using the <filename>boot.flp</filename> and
|
|
<filename>fixit.flp</filename> floppies, keep reading. Insert the
|
|
<filename>boot.flp</filename> floppy in the first floppy drive and
|
|
boot the computer. The original install menu will be displayed on
|
|
the screen. Select the <literal>Fixit--Repair mode with CDROM or
|
|
floppy.</literal> option. Insert the
|
|
<filename>fixit.flp</filename> when prompted.
|
|
<command>restore</command> and the other programs that you need are
|
|
located in <filename>/mnt2/stand</filename>.</para>
|
|
|
|
<para>Recover each filesystem separately.</para>
|
|
|
|
<para>Try to &man.mount.8; (e.g. <command>mount /dev/sd0a
|
|
/mnt</command>) the root partition of your first disk. If the
|
|
disklabel was damaged, use &man.disklabel.8; to re-partition and
|
|
label the disk to match the label that your printed and saved. Use
|
|
&man.newfs.8; to re-create the filesystems. Re-mount the root
|
|
partition of the floppy read-write (<command>mount -u -o rw
|
|
/mnt</command>). Use your backup program and backup tapes to
|
|
recover the data for this filesystem (e.g. <command>restore vrf
|
|
/dev/st0</command>). Unmount the filesystem (e.g. <command>umount
|
|
/mnt</command>) Repeat for each filesystem that was
|
|
damaged.</para>
|
|
|
|
<para>Once your system is running, backup your data onto new tapes.
|
|
Whatever caused the crash or data loss may strike again. An another
|
|
hour spent now, may save you from further distress later.</para>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>* I did not prepare for the Disaster, What Now?</title>
|
|
|
|
<para></para>
|
|
</sect3>
|
|
</sect2>
|
|
</sect1>
|
|
</chapter>
|
|
|
|
<!--
|
|
Local Variables:
|
|
mode: sgml
|
|
sgml-declaration: "../chapter.decl"
|
|
sgml-indent-data: t
|
|
sgml-omittag: nil
|
|
sgml-always-quote-attributes: t
|
|
sgml-parent-document: ("../handbook.sgml" "part" "chapter")
|
|
End:
|
|
-->
|