From: Mark Kirkwood <markir@coretech.co.nz>
To: pgsql-docs@postgresql.org
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Subject: Re: Instructions for Linux ipc config
Date: Sat, 05 Feb 2005 10:07:52 +1300
Message-ID: <4203E428.10302@coretech.co.nz> (raw)
In-Reply-To: <4202CD6B.3050203@coretech.co.nz>
References: <4202AE60.6000706@coretech.co.nz>
<5980.1107472704@sss.pgh.pa.us>
<4202CD6B.3050203@coretech.co.nz>
Attached are my first thoughts for the amended instructions.
Mark Kirkwood wrote:
>
> But to be on the safe side, it would make sense to do something similar
> to the BSD section, and comment about older distributions maybe needing
> to manipulate /proc/kernel/* directly.
>
Attachments:runtime.sgml.diff (text/plain, 2.7K) download--- runtime.sgml.orig Fri Feb 4 22:17:45 2005+++ runtime.sgml Fri Feb 4 22:17:57 2005@@ -4414,37 +4414,29 @@
<indexterm><primary>Linux</><secondary>IPC configuration</></>
<listitem>
<para>
- The default shared memory limit (both- <varname>SHMMAX</varname> and <varname>SHMALL</varname>) is 32- MB in 2.2 kernels, but it can be changed in the- <filename>proc</filename> file system (without reboot). For- example, to allow 128 MB:+ The default settings are only suitable for small installations + (the default max segment size is 32 MB). However the remaining+ defaults are quite generously sized, and usually do not require+ changes. The max segment size can be changed via the + <command>sysctl</command> interface. For example, to allow 128 MB, + and explicitly set the maximum total shared memory size to 2097152 + pages (the default):
<screen>
-<prompt>$</prompt> <userinput>echo 134217728 >/proc/sys/kernel/shmall</userinput>-<prompt>$</prompt> <userinput>echo 134217728 >/proc/sys/kernel/shmmax</userinput>+<prompt>$</prompt> <userinput>systcl -w kernel.shmmax=134217728</userinput>+<prompt>$</prompt> <userinput>systcl -w kernel.shmall=2097152</userinput>
</screen>
- You could put these commands into a script run at boot-time.- </para>-- <para>- Alternatively, you can use <command>sysctl</command>, if- available, to control these parameters. Look for a file- called <filename>/etc/sysctl.conf</filename> and add lines- like the following to it:-<programlisting>-kernel.shmall = 134217728-kernel.shmmax = 134217728-</programlisting>- This file is usually processed at boot time, but- <command>sysctl</command> can also be called- explicitly later.+ In addition these settings can be saved between reboots in + <filename>/etc/sysctl.conf.
</para>
<para>
- Other parameters are sufficiently sized for any application. If- you want to see for yourself look in- <filename>/usr/src/linux/include/asm-<replaceable>xxx</>/shmparam.h</>- and <filename>/usr/src/linux/include/linux/sem.h</>.+ Older distributions may not have the <command>sysctl</command> program,+ but equivalent changes can be made by manipulating the + <filename>/proc</filename> filesystem:+<screen>+<prompt>$</prompt> <userinput>echo 134217728 >/proc/sys/kernel/shmmax</userinput>+<prompt>$</prompt> <userinput>echo 2097152 >/proc/sys/kernel/shmall</userinput>+</screen>
</para>
</listitem>
</varlistentry>
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To: pgsql-docs@postgresql.org
Cc: markir@coretech.co.nz, tgl@sss.pgh.pa.us
Subject: Re: Instructions for Linux ipc config
In-Reply-To: <4203E428.10302@coretech.co.nz>
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