Re: Linux I/O schedulers - CFQ & random seeks - Mailing list pgsql-performance

From Wayne Conrad
Subject Re: Linux I/O schedulers - CFQ & random seeks
Date
Msg-id 4D712978.60504@databill.com
Whole thread Raw
In response to Linux I/O schedulers - CFQ & random seeks  (Glyn Astill <glynastill@yahoo.co.uk>)
Responses Re: Linux I/O schedulers - CFQ & random seeks  (Dan Harris <fbsd@drivefaster.net>)
List pgsql-performance
On 03/04/11 10:34, Glyn Astill wrote:
 > I'm wondering (and this may be a can of worms) what peoples opinions
are on these schedulers?

When testing our new DB box just last month, we saw a big improvement in
bonnie++ random I/O rates when using the noop scheduler instead of cfq
(or any other).  We've got RAID 10/12 on a 3ware card w/ battery-backed
cache; 7200rpm drives.  Our file system is XFS with
noatime,nobarrier,logbufs=8,logbsize=256k.  How much is "big?"  I can't
find my notes for it, but I recall that the difference was large enough
to surprise us.  We're running with noop in production right now.  No
complaints.

pgsql-performance by date:

Previous
From: Glyn Astill
Date:
Subject: Linux I/O schedulers - CFQ & random seeks
Next
From: Robert Haas
Date:
Subject: Re: Slow join on partitioned table