From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with SMTP id p3CB2ERH146592 for ; Tue, 12 Apr 2011 06:02:14 -0500 Received: from ipmail06.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 39CA11B6DDC7 for ; Tue, 12 Apr 2011 04:05:34 -0700 (PDT) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id DhFaklWLUurTquWf for ; Tue, 12 Apr 2011 04:05:34 -0700 (PDT) Date: Tue, 12 Apr 2011 21:05:32 +1000 From: Dave Chinner Subject: Re: fs corruption Message-ID: <20110412110532.GB31057@dastard> References: <31377534.post@talk.nabble.com> <20110412094917.GY31057@dastard> <38287.10078.qm@web112901.mail.gq1.yahoo.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <38287.10078.qm@web112901.mail.gq1.yahoo.com> 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: Leo Davis Cc: xfs@oss.sgi.com On Tue, Apr 12, 2011 at 03:51:20AM -0700, Leo Davis wrote: > You have a corrupted free space btree. > > Err... apologies for my ignorance, but what is a free space btree? A tree that indexes the free space in the filesystem. Every time you write a file or remove a file you are allocating or freeing space, and these tree keep track of that free space. If you want to know - at a high level - how XFS is structured (good for understanding what a free space tree is), read this paper: http://oss.sgi.com/projects/xfs/papers/xfs_usenix/index.html It's from 1996, but still correct on all the major structural details. > I had serial trace from raid controller which i just checked and > it logged some 'Loose cabling', but this was months back..... not > sure whether that can be the cause of this.. strange if that is > the case since it's been a long time it's possible that it took a couple of months to trip over a random metadata corruption. I've seen that before in directory trees and inode clusters where corruption is not detected until next time they are read from disk.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs