Re: OOM killer problem - how to read the kernel log?

From: Douglas McNaught
Date: Fri Nov 09 2007 - 17:31:19 EST


"Tobias Brox" <tobixen@xxxxxxxxx> writes:

> We have a database server which we've had some problems with, we've
> had some serious crashes (particularly during postgres vacuuming)
> which couldn't be fixed without hardware reboot. We assumed that the
> problem would go away by itself after upgrading the server to a new
> box with 32G of RAM ... but, alas, one of the first days in operation
> it first killed lots of postgres children during the evening, and
> finally it crashed and required hardware reboot. The box is certainly
> not out of memory, but after reading some posts here, I've understood
> that memory management is a complex issue.
>
> We're running 32 bits linux, maybe it would help to upgrade to 64 bits?

Big-time. There are a lot of "artificial" internal kernel memory
limits in the 32-bit architecture, so you can run up against those
(triggering the OOM killer) even if you have plenty of application
memory.

32GB in the box actually might be counter-productive unless you're
running 64-bit, because just tracking that much memory will consume
precious low kernel RAM.

-Doug
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