Update our information about OS X shared memory configuration: it's now

possible to set most of the SHM kernel parameters without a reboot.
Also, reorder the paragraph to explain the modern configuration method first.
There are probably not too many people who still care about how to do it on
OS X 10.3 or older.
This commit is contained in:
Tom Lane 2010-04-30 22:24:50 +00:00
parent 854b5eb510
commit 05f030837c

View file

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.434 2010/04/08 01:39:37 rhaas Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.435 2010/04/30 22:24:50 tgl Exp $ -->
<chapter Id="runtime">
<title>Server Setup and Operation</title>
@ -942,29 +942,8 @@ options SEMMAP=256
<indexterm><primary>MacOS X</><secondary>IPC configuration</></>
<listitem>
<para>
In OS X 10.2 and earlier, edit the file
<filename>/System/Library/StartupItems/SystemTuning/SystemTuning</>
and change the values in the following commands:
<programlisting>
sysctl -w kern.sysv.shmmax
sysctl -w kern.sysv.shmmin
sysctl -w kern.sysv.shmmni
sysctl -w kern.sysv.shmseg
sysctl -w kern.sysv.shmall
</programlisting>
</para>
<para>
In OS X 10.3 and later, these commands have been moved to
<filename>/etc/rc</> and must be edited there. Note that
<filename>/etc/rc</> is usually overwritten by OS X updates (such as
10.3.6 to 10.3.7) so you should expect to have to redo your edits
after each update.
</para>
<para>
In OS X 10.3.9 and later, instead of editing <filename>/etc/rc</>
you can create a file named <filename>/etc/sysctl.conf</>,
The recommended method for configuring shared memory in OS X
is to create a file named <filename>/etc/sysctl.conf</>,
containing variable assignments such as:
<programlisting>
kern.sysv.shmmax=4194304
@ -973,8 +952,7 @@ kern.sysv.shmmni=32
kern.sysv.shmseg=8
kern.sysv.shmall=1024
</programlisting>
This method is better than editing <filename>/etc/rc</> because
your changes will be preserved across system updates. Note that
Note that in some OS X versions,
<emphasis>all five</> shared-memory parameters must be set in
<filename>/etc/sysctl.conf</>, else the values will be ignored.
</para>
@ -989,8 +967,34 @@ kern.sysv.shmall=1024
</para>
<para>
In all OS X versions, you will need to reboot to have changes in the
shared memory parameters take effect.
In older OS X versions, you will need to reboot to have changes in the
shared memory parameters take effect. As of 10.5 it is possible to
change all but <varname>SHMMNI</> on the fly, using
<application>sysctl</>. But it's still best to set up your preferred
values via <filename>/etc/sysctl.conf</>, so that the values will be
kept across reboots.
</para>
<para>
The file <filename>/etc/sysctl.conf</> is only honored in OS X
10.3.9 and later. If you are running a previous 10.3.x release,
you must edit the file <filename>/etc/rc</>
and change the values in the following commands:
<programlisting>
sysctl -w kern.sysv.shmmax
sysctl -w kern.sysv.shmmin
sysctl -w kern.sysv.shmmni
sysctl -w kern.sysv.shmseg
sysctl -w kern.sysv.shmall
</programlisting>
Note that
<filename>/etc/rc</> is usually overwritten by OS X system updates,
so you should expect to have to redo these edits after each update.
</para>
<para>
In OS X 10.2 and earlier, instead edit these commands in the file
<filename>/System/Library/StartupItems/SystemTuning/SystemTuning</>.
</para>
</listitem>
</varlistentry>