Integrate tape backups into Backup Basics chapter.

This improves the flow as tar/dump are already covered.
The next commit will fix the formatting.

Sponsored by:	iXsystems
This commit is contained in:
Dru Lavigne 2014-04-09 18:14:01 +00:00
parent 3e479671b9
commit 6bb8c68447
Notes: svn2git 2020-12-08 03:00:23 +00:00
svn path=/head/; revision=44509

View file

@ -1675,89 +1675,6 @@ cd0: Attempt to query device size failed: NOT READY, Medium not present - tray c
Collection.</para>
</sect1>
<sect1 xml:id="backups-tapebackups">
<title>Creating and Using Data Tapes</title>
<indexterm><primary>tape media</primary></indexterm>
<para>While tape technology has continued to evolve,
modern backup systems tend to combine
off-site backups with local removable media.
&os; supports any tape drive that
uses <acronym>SCSI</acronym>, such as <acronym>LTO</acronym> or
<acronym>DAT</acronym>. There is limited support for <acronym>SATA</acronym>
and <acronym>USB</acronym> tape drives.</para>
<para>For <acronym>SCSI</acronym> tape devices, &os; uses the &man.sa.4; driver and the
<filename>/dev/sa0</filename>, <filename>/dev/nsa0</filename>,
and <filename>/dev/esa0</filename> devices. The physical device name is
<filename>/dev/sa0</filename>. When
<filename>/dev/nsa0</filename> is used, the backup application will
not rewind the
tape after writing a file, which allows writing more than one
file to a tape. Using <filename>/dev/esa0</filename>
ejects the tape after the device is closed.</para>
<para>This section summarizes how to configure and use a
<acronym>SCSI</acronym> tape device on &os;.</para>
<sect2>
<title xml:id="tapes-mt">Using a Tape Drive for Backups</title>
<indexterm>
<primary>tape media</primary>
<secondary>mt</secondary>
</indexterm>
<para>In &os;, <command>mt</command> is used to control
operations of the tape drive, such as seeking through files on
a tape or writing tape control marks to the tape. For
example, the first three files on a tape can be
preserved by skipping past them before writing a new
file:</para>
<screen>&prompt.root; <userinput>mt -f /dev/nsa0 fsf 3</userinput></screen>
<para>This utility supports many operations. Refer to
&man.mt.1; for details.</para>
<para>To write a single file to tape using
<command>tar</command>, specify the name of the tape device
and the file to backup:</para>
<screen>&prompt.root; <userinput>tar cvf /dev/sa0 <replaceable>file</replaceable></userinput></screen>
<para>To recovering files from a <command>tar</command> archive on tape into
the current directory:</para>
<screen>&prompt.root; <userinput>tar xvf /dev/sa0</userinput></screen>
<para>To backup a <acronym>UFS</acronym> file system, use
<command>dump</command>. This examples backs up
<filename>/usr</filename> without rewinding the tape when
finished:</para>
<screen>&prompt.root; <userinput>dump -0aL -b64 -f /dev/nsa0 /usr</userinput></screen>
<para>To interactively restore files from a <command>dump</command> file on
tape into the current directory:</para>
<screen>&prompt.root; <userinput>restore -i -f /dev/nsa0</userinput></screen>
</sect2>
<sect2>
<title xml:id="tapes-othersofware">Other Tape Software</title>
<para>Third-party programs are available to simplify tape
backup. The most popular are
<application>Amanda</application> and
<application>Bacula</application>. These programs aim to make
backups easier and more convenient, or to automate complex
backups of multiple machines. The Ports Collection contains
both these and other tape utility applications.</para>
</sect2>
</sect1>
<sect1 xml:id="backup-basics">
<title>Backup Basics</title>
@ -2009,6 +1926,65 @@ cd0: Attempt to query device size failed: NOT READY, Medium not present - tray c
</example>
</sect2>
<sect2 xml:id="backups-tapebackups">
<title>Using Data Tapes for Backups</title>
<indexterm><primary>tape media</primary></indexterm>
<para>While tape technology has continued to evolve,
modern backup systems tend to combine
off-site backups with local removable media.
&os; supports any tape drive that
uses <acronym>SCSI</acronym>, such as <acronym>LTO</acronym> or
<acronym>DAT</acronym>. There is limited support for <acronym>SATA</acronym>
and <acronym>USB</acronym> tape drives.</para>
<para>For <acronym>SCSI</acronym> tape devices, &os; uses the &man.sa.4; driver and the
<filename>/dev/sa0</filename>, <filename>/dev/nsa0</filename>,
and <filename>/dev/esa0</filename> devices. The physical device name is
<filename>/dev/sa0</filename>. When
<filename>/dev/nsa0</filename> is used, the backup application will
not rewind the
tape after writing a file, which allows writing more than one
file to a tape. Using <filename>/dev/esa0</filename>
ejects the tape after the device is closed.</para>
<para>In &os;, <command>mt</command> is used to control
operations of the tape drive, such as seeking through files on
a tape or writing tape control marks to the tape. For
example, the first three files on a tape can be
preserved by skipping past them before writing a new
file:</para>
<screen>&prompt.root; <userinput>mt -f /dev/nsa0 fsf 3</userinput></screen>
<para>This utility supports many operations. Refer to
&man.mt.1; for details.</para>
<para>To write a single file to tape using
<command>tar</command>, specify the name of the tape device
and the file to backup:</para>
<screen>&prompt.root; <userinput>tar cvf /dev/sa0 <replaceable>file</replaceable></userinput></screen>
<para>To recovering files from a <command>tar</command> archive on tape into
the current directory:</para>
<screen>&prompt.root; <userinput>tar xvf /dev/sa0</userinput></screen>
<para>To backup a <acronym>UFS</acronym> file system, use
<command>dump</command>. This examples backs up
<filename>/usr</filename> without rewinding the tape when
finished:</para>
<screen>&prompt.root; <userinput>dump -0aL -b64 -f /dev/nsa0 /usr</userinput></screen>
<para>To interactively restore files from a <command>dump</command> file on
tape into the current directory:</para>
<screen>&prompt.root; <userinput>restore -i -f /dev/nsa0</userinput></screen>
</sect2>
<sect2 xml:id="backups-programs-amanda">
<title>Third-Party Backup Utilities</title>
@ -2018,7 +1994,9 @@ cd0: Attempt to query device size failed: NOT READY, Medium not present - tray c
<para>The &os; Ports Collection provides many third-party
utilities which can be used to schedule the creation of
backups. Many of these applications are client/server based
backups, simplify tape backup, and make
backups easier and more convenient.
Many of these applications are client/server based
and can be used to automate the backups of a single system or
all of the computers in a network.</para>