<chapter Id="failure">
 <title>Database Failures</title>

 <para>
  Database failures (or the possibility of such) must be assumed to be
  lurking, ready to strike at some time in the future. A prudent
  database administrator will plan for the inevitability of failures
  of all possible kinds, and will have appropriate plans and
  procedures in place <emphasis>before</emphasis> the failure occurs.
 </para>

 <para>
  Database recovery is necessary in the event of hardware or software
  failure. There are several categories of failures; some of these
  require relatively minor adjustments to the database, while others
  may depend on the existance of previously prepared database dumps
  and other recovery data sets. It should be emphasized that if your
  data is important and/or difficult to regenerate, then you should
  have considered and prepared for various failure scenarios.
 </para>

 <sect1>
  <title>Disk Filled</title>

  <para>
   A filled data disk may result in subsequent corruption of database
   indexes, but not of the fundamental data tables. If the WAL files
   are on the same disk (as is the case for a default configuration)
   then a filled disk during database initialization may result in
   corrupted or incomplete WAL files. This failure condition is
   detected and the database will refuse to start up. You must free
   up additional space on the disk (or move the WAL area to another
   disk; see <xref linkend="wal-configuration">) and then restart the
   <application>postmaster</application> to recover from this condition.
  </para>
 </sect1>

 <sect1>
  <title>Disk Failed</title>

  <para>
   Failure of any disk (or of a logical storage device such as a RAID
   subsystem) involved with an active database will require
   that the database be recovered from a previously prepared database
   dump. This dump must be prepared using
   <application>pg_dumpall</application>, and updates to the database
   occuring after the database installation was dumped will be lost. 
  </para>
 </sect1>

<!--
 <sect1>
  <title>File Corrupted</title>

  <para>
  </para>
 </sect1>

 <sect1>
  <title>Table Corrupted</title>

  <para>
  </para>
 </sect1>

 <sect1>
  <title></title>

  <para>
  </para>
 </sect1>

 <sect1>
  <title></title>

  <para>
  </para>
 </sect1>

 <sect1>
  <title></title>

  <para>
  </para>
 </sect1>
-->

</chapter>

<!-- Keep this comment at the end of the file
Local variables:
mode:sgml
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document: ("postgres.sgml" "set" "book" "chapter")
sgml-default-dtd-file:"./reference.ced"
sgml-exposed-tags:nil
sgml-local-ecat-files:nil
End:
-->
