From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q5FCUb7E089497 for ; Fri, 15 Jun 2012 07:30:37 -0500 Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id OgONec5D6FhVWhCR for ; Fri, 15 Jun 2012 05:30:35 -0700 (PDT) Date: Fri, 15 Jun 2012 22:30:34 +1000 From: Dave Chinner Subject: Re: XFS hangs and freezes with LSI 9265-8i controller on high i/o Message-ID: <20120615123034.GC19223@dastard> References: <4FD66513.2000108@xsnews.nl> <20120612011812.GK22848@dastard> <4FD766A7.9030908@xsnews.nl> <20120613011950.GN22848@dastard> <4FD8552C.4090208@xsnews.nl> <20120614000411.GY22848@dastard> <4FD9F5B3.3040901@xsnews.nl> <20120615001602.GF7339@dastard> <4FDB1BA6.3030203@itwm.fraunhofer.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4FDB1BA6.3030203@itwm.fraunhofer.de> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Bernd Schubert Cc: Matthew Whittaker-Williams , xfs@oss.sgi.com On Fri, Jun 15, 2012 at 01:25:26PM +0200, Bernd Schubert wrote: > On 06/15/2012 02:16 AM, Dave Chinner wrote: > >Oh, I just noticed you are might be using CFQ (it's the default in > >dmesg). Don't - CFQ is highly unsuited for hardware RAID - it's > >hueristically tuned to work well on sngle SATA drives. Use deadline, > >or preferably for hardware RAID, noop. > > I'm not sure if noop is really a good recommendation even with hw > raid, especially if the the request queue size is high. This week I > did some benchmarks with a high rq write size (triggered with > sync_file_range(..., SYNC_FILE_RANGE_WRITE) ) and with noop > concuring reads then almost entirely got stalled. > With deadline read/write balance was much better, although writes > still had been preferred (with sync_file_range() and without). I > always thought deadline prefers reads and I hope I find some time > later on to investigate further what was going on. > Test had been on a netapp E5400 hw raid, so rather high end hw raid. Sounds like a case of the IO scheduler queue and/or CTQ being too deep. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs