RE: Linux, i/o scheduler and ASM

From: Kyle Brokaw <>
Date: Mon, 18 Apr 2011 10:37:35 -0600
Message-ID: <44CF9CE12FA17241B429870F1DAA5B460741B66D1C_at_LP-EXMBVS01.CO.IHC.COM>

We are in the middle of doing a POC and converting our 10tb Oracle AIX based DB to Red Hat Linux using Database Replay. When we replayed using the deadline scheduler it dropped our replay from 36 hours to 34. Not a huge gain but it definitely helped.

Kyle Brokaw

From: [] On Behalf Of Amaral, Rui Sent: Monday, April 18, 2011 10:25 AM
To: ''; Cc:
Subject: RE: Linux, i/o scheduler and ASM

Same here under a similar scenario - about 10% improvement on a load of 1 terabyte worth of data.

From: [] On Behalf Of K Gopalakrishnan Sent: Monday, April 18, 2011 12:18 PM
Subject: Re: Linux, i/o scheduler and ASM


Played with scheduler a while ago on a storage benchmark, (don't have the exact numbers handy) You will not see any noticeable difference during normal workload. But with overloaded (or fully loaded) systems, deadline scheduler works better than CFQ. The difference was in the range of 5-8% IIRC.


On Mon, Apr 18, 2011 at 10:51 AM, CRISLER, JON A (ATTCORP) <<>> wrote: Has anybody played around with changing the Linux I/O scheduler when using ASM (11gR2) ? I am wondering if any performance differences are to be found in using CFQ vs. Deadline vs other options, especially in a large RAC / SAN environment. Right now we are using CFQ, and in my previous experiments on filesystems I did not get any noticeable difference in changing to deadline.

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-- Received on Mon Apr 18 2011 - 11:37:35 CDT

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