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 q16DLYuV135089 for ; Mon, 6 Feb 2012 07:21:34 -0600 Received: from mail.sandeen.net (sandeen.net [63.231.237.45]) by cuda.sgi.com with ESMTP id weDKtPVzIrHURGu3 for ; Mon, 06 Feb 2012 05:21:32 -0800 (PST) Message-ID: <4F2FD3DC.3030301@sandeen.net> Date: Mon, 06 Feb 2012 07:21:32 -0600 From: Eric Sandeen 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> <4F2FB72B.9010209@rhul.ac.uk> In-Reply-To: <4F2FB72B.9010209@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 , xfs@oss.sgi.com 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. > 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. So fragmentation may not be the problem... -Eric >> 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