Re: Out of memory on SELECT in 8.3.5

From: Stephen Frost <sfrost(at)snowman(dot)net>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Matt Magoffin <postgresql(dot)org(at)msqr(dot)us>, pgsql-general(at)postgresql(dot)org
Subject: Re: Out of memory on SELECT in 8.3.5
Date: 2009-02-09 16:25:45
Message-ID: 20090209162544.GE8123@tamriel.snowman.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

* Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> OTOH ... wait a minute. Have you maybe got the system configured to
> start denying memory requests before it gets into significant swapping?
> We typically suggest setting vm.overcommit_memory=2 on Linux, but
> I'm not sure whether that results in the kernel trying to avoid using
> swap at all. Maybe this really is an issue with system-wide total
> memory use rather than any one process.

Err, yea, overcommit_memory=2, a small amount of swap space, and a low
overcommit_ratio could cause this to happen... The default
ratio is 50 though, which should mean, on this system, there is about
10G available for user processes, but his usage shows only a bit over 2G
being used outside of buffers/caches (based on free output)..

Matt, can you provide the output from these:
cat /proc/sys/vm/overcommit_memory

cat /proc/sys/vm/overcommit_ratio

cat /proc/meminfo

?

Thanks,

Stephen

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Lee Hughes 2009-02-09 16:52:15 Convert Arbitrary Table to Array?
Previous Message Tom Lane 2009-02-09 15:47:15 Re: Out of memory on SELECT in 8.3.5