To: Gavin Kistner <phrogz@mac.com>
cc: pgsql-admin@postgresql.org
Subject: Re: Fresh build on OS X not working (memory) 
In-reply-to: <BC88739D-8F46-4750-ADBA-C6F170EC412C@mac.com> 
References: <88181C2E-01CD-417C-8266-D5C9AF570C27@mac.com>
	<15253.1272606140@sss.pgh.pa.us>
	<BC88739D-8F46-4750-ADBA-C6F170EC412C@mac.com>
Comments: In-reply-to Gavin Kistner <phrogz@mac.com>
	message dated "Thu, 29 Apr 2010 23:58:54 -0600"
Date: Fri, 30 Apr 2010 11:57:45 -0400
Message-ID: <25928.1272643065@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Gavin Kistner <phrogz@mac.com> writes:
> On Apr 29, 2010, at 11:42 PM, Tom Lane wrote:
>> For comparison, I have these settings on my laptop:
>> pro:~ tgl$ cat /etc/sysctl.conf 
>> kern.sysv.shmmax=33554432
>> kern.sysv.shmmin=1
>> kern.sysv.shmmni=32
>> kern.sysv.shmseg=8
>> kern.sysv.shmall=8192
>> 
>> and PG starts fine for me.

> I'm not sure what magic you have in there, but this incantation copied verbatim worked for me. Thanks!

> The first sysctl.conf I tried that didn't work from from the one-click installer's README. Do you see anything about the following settings that jumps out at you as bad? Is it notable that yours don't set the maxproc*?

> kern.sysv.shmmax=1610612736
> kern.sysv.shmall=393216
> kern.sysv.shmmin=1
> kern.sysv.shmmni=32
> kern.sysv.shmseg=8
> kern.maxprocperuid=512
> kern.maxproc=2048

I have no idea why EDB recommend changing the maxproc settings, but
I doubt that's related to shared memory.  I see that they have shmmax
equal to exactly 4096 times shmall, so that's good, but there must be
some other OSX peculiarity that this is tripping over.  Maybe it's too
large ... do you actually have 1.6GB of RAM available that could
reasonably be dedicated to PG shared memory?  Another possibility is
that maybe only exact powers of 2 work well.  I'm just guessing though.

			regards, tom lane