Document possible problems with NFS tablespaces.

This commit is contained in:
Bruce Momjian 2007-11-04 21:40:02 +00:00
parent 5e0377ae7e
commit 3372380cc4
1 changed files with 27 additions and 1 deletions

View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.55 2007/11/04 19:43:33 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.56 2007/11/04 21:40:02 momjian Exp $ -->
<chapter id="managing-databases">
<title>Managing Databases</title>
@ -495,5 +495,31 @@ SELECT spcname FROM pg_tablespace;
the old tablespace locations.)
</para>
<sect2 id="manage-ag-tablespaces-nfs">
<title>Network File Systems</title>
<indexterm zone="manage-ag-tablespaces-nfs">
<primary>Network File Systems</primary>
</indexterm>
<indexterm><primary><acronym>NFS</></><see>Network File Systems</></>
<indexterm><primary>Network Attached Storage (<acronym>NAS</>)</><see>Network File Systems</></>
<para>
Many installations create tablespace on network file systems.
Sometimes this is done directly via <acronym>NFS</>, or by using a
Network Attached Storage (<acronym>NAS</>) device that uses
<acronym>NFS</> internally. <productname>PostgreSQL</> does nothing
special for <acronym>NFS</> file systems, meaning it assumes
<acronym>NFS</> behaves exactly like locally-connected drives. If
client and server <acronym>NFS</> implementations have non-standard
semantics, this can cause reliability problems (see <ulink
url="http://www.time-travellers.org/shane/papers/NFS_considered_harmful.html"></ulink>).
Specifically, delayed (asynchonous) writes to the <acronym>NFS</>
server can cause reliability problems; if possible, mount
<acronym>NFS</> file systems synchonously to avoid this.
</para>
</sect2>
</sect1>
</chapter>