Huge whitespace changes. Translators can ignore this commit completely.
Rationale: All the changes to the DocBook handbook so far have been careful to keep whitespace changes to a minimum. This is so the translators have as easy a job as possible in identifying exactly what's changed. This has meant the English version has become more and more 'ugly'. Lines indented by the wrong amount, some lines longer than 130 characters, others shorter than 20, gaps of 3 or 4 lines between paragraphs (and sometimes within paragraphs). This makes it difficult to follow the structure of the document, and needlessly complicates fixing SGML problems. It also makes the source practically useless as a teaching aid; the more baroque the source looks, the less likely people are to dive in and contribute. This commit fixes all that -- and boy was it tedious. The snag is, it's touched almost every line in every file in the Handbook. Technically, the changes were made by running (in Emacs) sgml-indent-or-tab (bound to the TAB key) on almost each line (except those in <programlisting>, <screen>, <literallayout>, and other verbatim sections), and then running sgml-fill-element (bound to C-c C-q) on most paragraphs. FWIW, this is the first, only, and last change of this type contemplated.
This commit is contained in:
Nik Clayton
parent
62a7d13816
commit
1e28ab5a96
Notes:
svn2git
2020-12-08 03:00:23 +00:00
svn path=/head/; revision=4472
93 changed files with 123203 additions and 116140 deletions
|
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@ -9,10 +9,10 @@
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impossible to provide a exhaustive listing of hardware that FreeBSD
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supports, this section serves as a catalog of the device drivers included
|
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with FreeBSD and the hardware each drivers supports. Where possible and
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appropriate, notes about specific products are included. You may also want
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to refer to <link linkend="kernelconfig-config"> the kernel configuration
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file</link> section in this handbook for a list of supported
|
||||
devices.</para>
|
||||
appropriate, notes about specific products are included. You may also
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want to refer to <link linkend="kernelconfig-config"> the kernel
|
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configuration file</link> section in this handbook for a list of
|
||||
supported devices.</para>
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<para>As FreeBSD is a volunteer project without a funded testing department,
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we depend on you, the user, for much of the information contained in this
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|
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@ -37,8 +37,7 @@
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DLT.</para>
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<sect2 id="backups-tapebackups-4mm">
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<title>4mm (DDS: Digital Data
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Storage)</title>
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<title>4mm (DDS: Digital Data Storage)</title>
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<para>4mm tapes are replacing QIC as the workstation backup media of
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choice. This trend accelerated greatly when Conner purchased Archive,
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@ -52,9 +51,9 @@
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<para>Data thruput on these drives starts ~150kB/s, peaking at ~500kB/s.
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Data capacity starts at 1.3 GB and ends at 2.0 GB. Hardware
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compression, available with most of these drives, approximately
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doubles the capacity. Multi-drive tape library units can have 6 drives
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in a single cabinet with automatic tape changing. Library capacities
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reach 240 GB.</para>
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doubles the capacity. Multi-drive tape library units can have 6
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drives in a single cabinet with automatic tape changing. Library
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capacities reach 240 GB.</para>
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<para>4mm drives, like 8mm drives, use helical-scan. All the benefits
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and drawbacks of helical-scan apply to both 4mm and 8mm drives.</para>
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@ -65,32 +64,32 @@
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<sect2 id="backups-tapebackups-8mm">
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<title>8mm (Exabyte)</title>
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<para>8mm tapes are the most common SCSI tape drives; they are the best
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choice of exchanging tapes. Nearly every site has an exabyte 2 GB 8mm
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tape drive. 8mm drives are reliable, convenient and quiet. Cartridges
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tape drive. 8mm drives are reliable, convenient and quiet. Cartridges
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are inexpensive and small (4.8 x 3.3 x 0.6 inches; 122 x 84 x 15 mm).
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One downside of 8mm tape is relatively short head and tape life due to
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the high rate of relative motion of the tape across the heads.</para>
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<para>Data thruput ranges from ~250kB/s to ~500kB/s. Data sizes start at
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300 MB and go up to 7 GB. Hardware compression, available with most of
|
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these drives, approximately doubles the capacity. These drives are
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available as single units or multi-drive tape libraries with 6 drives
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and 120 tapes in a single cabinet. Tapes are changed automatically by
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the unit. Library capacities reach 840+ GB.</para>
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<para>Data thruput ranges from ~250kB/s to ~500kB/s. Data sizes start
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at 300 MB and go up to 7 GB. Hardware compression, available with
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most of these drives, approximately doubles the capacity. These
|
||||
drives are available as single units or multi-drive tape libraries
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with 6 drives and 120 tapes in a single cabinet. Tapes are changed
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automatically by the unit. Library capacities reach 840+ GB.</para>
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|
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<para>Data is recorded onto the tape using helical-scan, the heads are
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positioned at an angle to the media (approximately 6 degrees). The
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tape wraps around 270 degrees of the spool that holds the heads. The
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spool spins while the tape slides over the spool. The result is a high
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density of data and closely packed tracks that angle across the tape
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from one edge to the other.</para>
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spool spins while the tape slides over the spool. The result is a
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high density of data and closely packed tracks that angle across the
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tape from one edge to the other.</para>
|
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</sect2>
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<sect2 id="backups-tapebackups-qic">
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<title>QIC</title>
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<para>QIC-150 tapes and drives are, perhaps, the most common tape drive
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and media around. QIC tape drives are the least expensive "serious"
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backup drives. The downside is the cost of media. QIC tapes are
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|
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@ -100,21 +99,22 @@
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<emphasis>most</emphasis> common tape drive. Every site has a QIC
|
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drive of some density or another. Therein lies the rub, QIC has a
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||||
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>
|
||||
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
|
||||
<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
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@ -128,7 +128,7 @@
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|||
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<para></para>
|
||||
</sect2>
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||||
|
||||
|
||||
<sect2 id="backups-tapebackups-dlt">
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||||
<title>DLT</title>
|
||||
|
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|
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@ -156,19 +156,17 @@
|
|||
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
|
||||
<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>
|
||||
|
|
@ -178,12 +176,11 @@ st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|||
|
||||
<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>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>&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>
|
||||
|
||||
|
|
@ -195,92 +192,89 @@ st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|||
<title>Backup Programs</title>
|
||||
|
||||
<para>The three major programs are
|
||||
&man.dump.8;,
|
||||
&man.tar.1;,
|
||||
&man.dump.8;,
|
||||
&man.tar.1;,
|
||||
and
|
||||
&man.cpio.1;.</para>
|
||||
&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.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
|
||||
<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>
|
||||
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>&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>
|
||||
<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; 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>
|
||||
<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>
|
||||
<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">
|
||||
|
|
@ -290,9 +284,9 @@ st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|||
(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
|
||||
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
|
||||
|
|
@ -312,9 +306,9 @@ st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|||
<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>
|
||||
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
|
||||
|
|
@ -334,19 +328,20 @@ st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|||
<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>
|
||||
<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>
|
||||
|
|
@ -370,14 +365,14 @@ st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|||
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>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>
|
||||
|
|
@ -385,19 +380,19 @@ st0(ncr1:4:0): Logical unit is in process of becoming ready</screen>
|
|||
<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>
|
||||
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>
|
||||
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>
|
||||
|
||||
|
|
@ -554,7 +549,7 @@ chmod 644 /mnt/etc/passwd
|
|||
#
|
||||
/sbin/umount /mnt]]></programlisting>
|
||||
</sect3>
|
||||
|
||||
|
||||
<sect3>
|
||||
<title>After the Disaster</title>
|
||||
|
||||
|
|
@ -586,13 +581,13 @@ chmod 644 /mnt/etc/passwd
|
|||
/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>
|
||||
&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
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue