Re: tuning for AIX 5L with large memory - Mailing list pgsql-performance

From Chris Browne
Subject Re: tuning for AIX 5L with large memory
Date
Msg-id 60brkbdu0r.fsf@dev6.int.libertyrms.info
Whole thread Raw
In response to tuning for AIX 5L with large memory  (Dan Harris <fbsd@drivefaster.net>)
List pgsql-performance
neilc@samurai.com (Neil Conway) writes:
> Christopher Browne wrote:
>> One of our sysadmins did all the "configuring OS stuff" part; I don't
>> recall offhand if there was a need to twiddle something in order to
>> get it to have great gobs of shared memory.
>
> FWIW, the section on configuring kernel resources under various
> Unixen[1] doesn't have any documentation for AIX. If someone out there
> knows which knobs need to be tweaked, would they mind sending in a doc
> patch? (Or just specifying what needs to be done, and I'll add the
> SGML.)

After verifying that nobody wound up messing with the kernel
parameters, here's a docs patch...

Index: runtime.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql-server/doc/src/sgml/runtime.sgml,v
retrieving revision 1.263
diff -c -u -r1.263 runtime.sgml
--- runtime.sgml    29 Apr 2004 04:37:09 -0000    1.263
+++ runtime.sgml    26 May 2004 16:35:43 -0000
@@ -3557,6 +3557,26 @@
       </listitem>
      </varlistentry>

+     <varlistentry>
+      <term><systemitem class="osname">AIX</></term>
+      <indexterm><primary>AIX</><secondary>IPC configuration</></>
+      <listitem>
+       <para>
+        At least as of version 5.1, it should not be necessary to do
+        any special configuration for such parameters as
+        <varname>SHMMAX</varname>, as it appears this is configured to
+        allow all memory to be used as shared memory.  That is the
+        sort of configuration commonly used for other databases such
+        as <application>DB/2</application>.</para>
+
+       <para> It may, however, be necessary to modify the global
+       <command>ulimit</command> information in
+       <filename>/etc/security/limits</filename>, as the default hard
+       limits for filesizes (<varname>fsize</varname>) and numbers of
+       files (<varname>nofiles</varname>) may be too low.
+       </para>
+      </listitem>
+     </varlistentry>

      <varlistentry>
       <term><systemitem class="osname">Solaris</></term>
--
select 'cbbrowne' || '@' || 'acm.org';
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