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>Number: 89900 >Category: docs >Synopsis: [PATCH] new text on backup strategies for Handbook >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-doc >State: open >Quarter: >Keywords: >Date-Required: >Class: change-request >Submitter-Id: current-users >Arrival-Date: Sat Dec 03 22:20:02 GMT 2005 >Closed-Date: >Last-Modified: >Originator: Lowell Gilbert >Release: FreeBSD 6.0-STABLE i386 >Organization: n/a >Environment: System: FreeBSD be-well.ilk.org 6.0-STABLE FreeBSD 6.0-STABLE #5: Tue Nov 29 19:56:53 EST 2005 root@be-well.ilk.org:/usr/src/sys/i386/compile/BE-WELL6 i386 >Description: This is new text discussing how to choose backup strategies. >How-To-Repeat: n/a >Fix: --- en_US.ISO8859-1/books/handbook/disks/chapter.sgml.ORIG Fri Aug 5 15:06:20 2005 +++ en_US.ISO8859-1/books/handbook/disks/chapter.sgml Sat Dec 3 16:03:31 2005 @@ -2269,8 +2269,103 @@ restore it, even if you have not asked it to!</para> </sect2> </sect1> + <sect1 id="backup-strategies"> + <title>Backup Strategies</title> + + <para> + The first requirement in devising a backup plan is to make sure that all of the + following problems are covered: + <itemizedlist> + <listitem> + <para> + disk failure + </para> + </listitem> + <listitem> + <para> + accidental file deletion + </para> + </listitem> + <listitem> + <para> + random file corruption + </para> + </listitem> + <listitem> + <para> + complete machine destruction (e.g., fire) including destruction of any on-site backups + </para> + </listitem> + </itemizedlist></para> + + <para>It is perfectly possible that some systems will be best served by + having each of these problems covered by a completely different + technique. Except for strictly personal systems with very low-value + data, it is unlikely that one technique would cover all of them.</para> + + <para>Some of the techniques in the toolbox are:</para> + <itemizedlist> + <listitem> + <para>archives of the whole system, backed up onto permanent media + offsite. This actually provides protection against all of the + possible problems listed above, but is slow and inconvenient to + restore from. You can keep copies of the backups onsite and/or + online, but there will still be inconveniences in restoring files, + especially for non-privileged users.</para> + </listitem> + + <listitem> + <para>filesystem snapshots. This is really only helpful in the + accidental file deletion scenario, but it can be + <emphasis>very</emphasis> helpful + in that case, and is quick and easy to deal with.</para> + </listitem> + + <listitem> + + <para> copies of whole filesystems and/or disks. [for example, + periodic rsync of the whole machine] This is generally most + useful in networks with unique requirements. For general + protection against disk failure, it is usually inferior to + <acronym>RAID</acronym>. For restoring accidentally deleted + files, it can be comparable to <acronym>UFS</acronym> + snapshots, but that depends on your preferences.</para> + + </listitem> + + <listitem> + + <para><acronym>RAID</acronym>. Minimizes or avoids downtime + when a disk fails. At the expense of having to deal with disk + failures more often (because you have more disks), albeit at a + much lower urgency.</para> + + </listitem> + + <listitem> + + <para>checking fingerprints of files. The + &man.mtree.8; + program is very useful for this. Although it is not a backup + technique, it helps guarantee that you will notice when you need + to resort to your backups. This is particularly important for + offline backups, and should be checked periodically. + + </listitem> + </itemizedlist> + + <para>It is quite easy to come up with even more techniques, many of them + variations on the ones listed above. Specialized requirements will + usually lead to specialized techniques (for example, backing up a live + database usually requires a method particular to the database + software as an intermediate step). The important thing is to know + what dangers you want to protect against, and how you will handle + each.</para> + + </sect1> + <sect1 id="backup-basics"> <title>Backup Basics</title> <para>The three major backup programs are >Release-Note: >Audit-Trail: >Unformatted: _______________________________________________ freebsd-doc@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-doc To unsubscribe, send any mail to "freebsd-doc-unsubscribe@freebsd.org"