From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Landman Subject: Re: rescue an alien md raid5 Date: Mon, 23 Feb 2009 13:58:48 -0500 Message-ID: <49A2F1E8.6030901@scalableinformatics.com> References: <200902231013.46082.harry.mangalam@uci.edu> Reply-To: landman@scalableinformatics.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200902231013.46082.harry.mangalam@uci.edu> Sender: linux-raid-owner@vger.kernel.org To: Harry Mangalam Cc: linux-raid List-Id: linux-raid.ids Harry Mangalam wrote: > Here's an unusual (long) tale of woe. > > We had a USRobotics 8700 NAS appliance with 4 SATA disks in RAID5: > > which was a fine (if crude) ARM-based Linux NAS until it stroked out > at some point, leaving us with a degraded RAID5 and comatose NAS > device. > > We'd like to get the files back of course and I've moved the disks to > a Linux PC, hooked them up to a cheap Silicon Image 4x SATA > controller and brought up the whole frankenmess with mdadm. It > reported a clean but degraded array: > > =============================================================== > > root@pnh-rcs:/# mdadm --detail /dev/md0 > /dev/md0: > Version : 00.90.03 > The docs and files on the USR web site imply that the native > filesystem was originally XFS, but when i try to mount it as such, I > can't: > > mount -vvv -t xfs /dev/md1 /mnt > mount: fstab path: "/etc/fstab" > mount: lock path: "/etc/mtab~" > mount: temp path: "/etc/mtab.tmp" > mount: no LABEL=, no UUID=, going to mount /dev/md1 by path > mount: spec: "/dev/md1" > mount: node: "/mnt" > mount: types: "xfs" > mount: opts: "(null)" > mount: mount(2) syscall: source: "/dev/md1", target: "/mnt", > filesystemtype: "xfs", mountflags: -1058209792, data: (null) > mount: wrong fs type, bad option, bad superblock on /dev/md1, > missing codepage or helper program, or other error > In some cases useful info is found in syslog - try > dmesg | tail or so Hmmm... is it possible that the journal is external for the XFS filesystem in question? Could you try mount -o norecovery,ro /dev/md1 /mountpoint Otherwise, could you dd the file system off there onto another (large) partition, before you try xfs_repair -- Joseph Landman, Ph.D Founder and CEO Scalable Informatics LLC, email: landman@scalableinformatics.com web : http://www.scalableinformatics.com http://jackrabbit.scalableinformatics.com phone: +1 734 786 8423 x121 fax : +1 866 888 3112 cell : +1 734 612 4615