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 q16BJQmX125545 for ; Mon, 6 Feb 2012 05:19:26 -0600 Received: from gse-mta-17.emailfiltering.com (ixe-mta-17-tx.emailfiltering.com [194.116.198.149]) by cuda.sgi.com with ESMTP id B5tbUlfoX00KuHSy (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Mon, 06 Feb 2012 03:19:24 -0800 (PST) Message-ID: <4F2FB72B.9010209@rhul.ac.uk> Date: Mon, 6 Feb 2012 11:19:07 +0000 From: Tom Crane MIME-Version: 1.0 Subject: Re: xfs_repair segfaults with ag_stride option References: <4F293FCC.7010101@rhul.ac.uk> <20120202124248.GA12107@infradead.org> <4F2F23F3.9000402@rhul.ac.uk> <4F2F6C00.5050108@sandeen.net> In-Reply-To: <4F2F6C00.5050108@sandeen.net> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Eric Sandeen Cc: Christoph Hellwig , T.Crane@rhul.ac.uk, xfs@oss.sgi.com Eric Sandeen wrote: > On 2/5/12 6:50 PM, Tom Crane wrote: > >> Hi Christoph, >> Many thanks for the quick response and the patch. It was a big help. >> I was able to repair our 60TB FS in about 30 hours. I have a couple >> of questions; >> >> (1) The steps in the progress report seem a little strange. See the >> attachment. Is this expected? >> >> (2) This may be a little out of band but I have heard second hand >> reports from another sysadmin that the xfs tools which come with SLC5 >> (our current Linux distro) should not be relied upon and that SLC6 >> should be used. Our 60TB FS is significantly fragmented (~40%) and I >> would very much like to run xfs_fsr on it. Given that I have built >> the latest xfsprogs, is there any reason I should be afraid of >> running xfs_fsr, on the FS which comes with SLC5? Unfortunately I >> don't have ~60TB spare storage space elsewhere to backup the FS >> before defragging. What would you advise?> >> Many thanks >> > > 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 Some users on our compute farm with large jobs (lots of I/O) find they take longer than with some of our other scratch arrays hosted on other machines. We also typically find many nfsd tasks in an uninterruptible wait state (sync_page), waiting for data to be copied in from the FS. > you see perf problems which you know you can attribute to fragmentation, > I might not worry about it. > > You can also check the fragmentation of individual files with the > xfs_bmap tool. > > -Eric > Thanks for your advice. Cheers Tom. > >> Tom. >> >> Christoph Hellwig wrote: >> >>> Hi Tom, >>> >>> On Wed, Feb 01, 2012 at 01:36:12PM +0000, Tom Crane wrote: >>> >>> >>>> Dear XFS Support, >>>> I am attempting to use xfs_repair to fix a damaged FS but always >>>> get a segfault if and only if -o ag_stride is specified. I have >>>> tried ag_stride=2,8,16 & 32. The FS is approx 60T. I can't find >>>> reports of this particular problem on the mailing list archive. >>>> Further details are; >>>> >>>> xfs_repair version 3.1.7, recently downloaded via git repository. >>>> uname -a >>>> Linux store3 2.6.18-274.17.1.el5 #1 SMP Wed Jan 11 11:10:32 CET 2012 >>>> x86_64 x86_64 x86_64 GNU/Linux >>>> >>>> >>> Thanks for the detailed bug report. >>> >>> Can you please try the attached patch? >>> >>> >>> >> _______________________________________________ >> xfs mailing list >> xfs@oss.sgi.com >> http://oss.sgi.com/mailman/listinfo/xfs >> > > _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs