From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q1890iFb052324 for ; Wed, 8 Feb 2012 03:00:44 -0600 Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id Z2xTU5s0tAcr5MsK for ; Wed, 08 Feb 2012 01:00:42 -0800 (PST) Date: Wed, 8 Feb 2012 20:00:41 +1100 From: Dave Chinner Subject: Re: xfs_repair segfaults with ag_stride option Message-ID: <20120208090041.GJ20305@dastard> References: <4F293FCC.7010101@rhul.ac.uk> <20120202124248.GA12107@infradead.org> <4F2F23F3.9000402@rhul.ac.uk> <4F2F6C00.5050108@sandeen.net> <4F2FB72B.9010209@rhul.ac.uk> <4F2FD3DC.3030301@sandeen.net> <4F316236.7050607@rhul.ac.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4F316236.7050607@rhul.ac.uk> 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: Tom Crane Cc: Christoph Hellwig , Eric Sandeen , xfs@oss.sgi.com On Tue, Feb 07, 2012 at 05:41:10PM +0000, Tom Crane wrote: > Eric Sandeen wrote: > >On 2/6/12 5:19 AM, Tom Crane wrote: > >>Eric Sandeen wrote: > > > >... > > > >>>Newer tools are fine to use on older filesystems, there should be no > >>Good! > >> > >>>issue there. > >>> > >>>running fsr can cause an awful lot of IO, and a lot of file reorganization. > >>>(meaning, they will get moved to new locations on disk, etc). > >>> > >>>How bad is it, really? How did you arrive at the 40% number? Unless > >>xfs_db -c frag -r > > > >which does: > > > > answer = (double)(extcount_actual - extcount_ideal) * 100.0 / > > (double)extcount_actual; > > > >If you work it out, if every file was split into only 2 extents, you'd have > >"50%" - and really, that's not bad. 40% is even less bad. > > Here is a list of some of the more fragmented files, produced using, > xfs_db -r /dev/mapper/vg0-lvol0 -c "frag -v" | head -1000000 | sort > -k4,4 -g | tail -100 > > >inode 1323681 actual 12496 ideal 2 > >inode 1324463 actual 12633 ideal 2 ..... > >inode 1320625 actual 20579 ideal 2 > >inode 1335016 actual 22701 ideal 2 > >inode 753185 actual 33483 ideal 2 > >inode 64515 actual 37764 ideal 2 > >inode 76068 actual 41394 ideal 2 > >inode 76069 actual 65898 ideal 2 Ok, so that looks like you have a fragmentation problem here. What is the workload that is generating these files? Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs