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From: Andy Colson <andy@squeakycode.net>
To: Craig Ringer <craig@postnewspapers.com.au>
To: pgsql-performance@postgresql.org
Subject: Re: a heavy duty operation on an "unused" table kills my server
Date: Thu, 14 Jan 2010 08:49:36 -0600
Message-ID: <4B4F2F00.7070401@squeakycode.net> (raw)
In-Reply-To: <4B4EAD76.9030305@postnewspapers.com.au>
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	<4B4EAD76.9030305@postnewspapers.com.au>

On 1/13/2010 11:36 PM, Craig Ringer wrote:
> Robert Haas wrote:
>
>> I'm kind of surprised that there are disk I/O subsystems that are so
>> bad that a single thread doing non-stop I/O can take down the whole
>> server.  Is that normal?
>
> No.
>
>> Does it happen on non-Windows operating
>> systems?
>
> Yes. My 3ware 8500-8 on a Debian Sarge box was so awful that launching a
> terminal would go from a 1/4 second operation to a 5 minute operation
> under heavy write load by one writer. I landed up having to modify the
> driver to partially mitigate the issue, but a single user on the
> terminal server performing any sort of heavy writing would still
> absolutely nuke performance.

On a side note, on linux, would using the deadline scheduler resolve that?

-Andy



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