From: Tom Lane <tgl@sss.pgh.pa.us>
To: Gavin Kistner <phrogz@mac.com>
Cc: pgsql-admin@postgresql.org
Subject: Re: Fresh build on OS X not working (memory)
Date: Sat, 01 May 2010 18:52:19 -0400
Message-ID: <10669.1272754339@sss.pgh.pa.us> (raw)
In-Reply-To: <7169B689-E23A-4B3C-B935-E88F2F2558EA@mac.com>
References: <88181C2E-01CD-417C-8266-D5C9AF570C27@mac.com>
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<BC88739D-8F46-4750-ADBA-C6F170EC412C@mac.com>
<25928.1272643065@sss.pgh.pa.us>
<16976.1272663334@sss.pgh.pa.us>
<7169B689-E23A-4B3C-B935-E88F2F2558EA@mac.com>
Gavin Kistner <phrogz@mac.com> writes:
> On Apr 30, 2010, at 3:35 PM, Tom Lane wrote:
>> Does the theory of a pre-existing smaller shmem segment make sense from
>> your end? In particular, had you previously had another Postgres server
>> running on that machine, and perhaps killed it ungracefully?
> It seems probably that you have hit the nail squarely on the head. I had installed from the one-click (which was working with the memory changes supplied in the README), and IIRC I tried to kill a few processes in preparation for a manual uninstall before I found the supplied uninstall app. I then compiled and installed from source. When that failed as described earlier, all changes I made to the settings were (as you guessed) through the sysctl -w option without a reboot. The first reboot I had was after I replaced my sysctl.conf wholesale with yours, and all was well.
Yeah, I was able to reproduce the problem locally by kill -9'ing the
postmaster and then enlarging max_connections in postgresql.conf before
trying to restart. In your case it might've been caused by the new
version needing a bit more shared memory rather than by any change in
parameter settings, but the basic issue seems pretty clear now.
I've applied a patch to our CVS to make PG behave more sanely in this
case. It does do the right thing if it recognizes that the shmget
failure is due to a pre-existing segment, but we weren't being
sufficiently careful about distinguishing that from a bad size request.
Thanks for the report!
regards, tom lane
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To: pgsql-admin@postgresql.org
Cc: tgl@sss.pgh.pa.us, phrogz@mac.com
Subject: Re: Fresh build on OS X not working (memory)
In-Reply-To: <10669.1272754339@sss.pgh.pa.us>
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