From: Michael Stone <mstone+postgres@mathom.us>
To: Dan Harris <fbsd@drivefaster.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: Query plan looks OK, but slow I/O - settings advice?
Date: Sat, 20 Aug 2005 08:15:04 -0400
Message-ID: <20050820121504.GL19080@mathom.us> (raw)
In-Reply-To: <E0CDF4BA-278D-4EFA-9438-A5BA4802C158@drivefaster.net>
References: <DB28E9B548192448A4E8C8A3C1B1E475611C66@sj1-exch-01.us.corp.kailea.com>
<1124434535.3257.7.camel@noodles>
<E0CDF4BA-278D-4EFA-9438-A5BA4802C158@drivefaster.net>
On Sat, Aug 20, 2005 at 12:52:08AM -0600, Dan Harris wrote:
>On Aug 19, 2005, at 12:55 AM, Jeffrey W. Baker wrote:
>> Have you considered booting your
>>machine with elevator=deadline?
>
>Although I'm not the OP for this problem, I thought I'd try it out.
>WOW.. this should be in a Pg tuning guide somewhere.
[snip]
>16-drive RAID 10
Yeah, the default scheduler tries to optimize disk access patterns for a
single-spindle setup, and actually makes things worse if you have a
device with multiple spindles.
Mike Stone
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To: pgsql-performance@postgresql.org
Cc: mstone+postgres@mathom.us, fbsd@drivefaster.net
Subject: Re: Query plan looks OK, but slow I/O - settings advice?
In-Reply-To: <20050820121504.GL19080@mathom.us>
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