Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261834AbVD1DJD (ORCPT ); Wed, 27 Apr 2005 23:09:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261837AbVD1DJD (ORCPT ); Wed, 27 Apr 2005 23:09:03 -0400 Received: from bee.hiwaay.net ([216.180.54.11]:30107 "EHLO bee.hiwaay.net") by vger.kernel.org with ESMTP id S261834AbVD1DI5 (ORCPT ); Wed, 27 Apr 2005 23:08:57 -0400 Date: Wed, 27 Apr 2005 22:08:56 -0500 From: Chris Adams To: linux-kernel@vger.kernel.org Subject: Re: RFH: ext3 on EVMS on SW-RAID1 problem Message-ID: <20050428030856.GA699498@hiwaay.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050427114648.GA17153@titan.lahn.de> User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2761 Lines: 79 Once upon a time, Philipp Matthias Hahn said: >One of our university fileservers shows strange problems since last >friday. Syslog show the following messages: > attempt to access beyond end of device > dm-8: rw=0, want=8589934592, limit=262142 >The strange thing: If I mount a disk-image of that volume via loop, >everything works fine! > >The server was running Debian sarge with an unpatched 2.6.11.6 than, but >is running an 2.6.11.7 now and still shows the same problem. >EVMS is version 2.5.2-1 and DevMapper is version 1.01.00-4. I see a similar problem under recent Fedora Core 3 kernels with LVM2. It appears when I create a snapshot of a volume. See Red Hat's Bugzilla: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=152162 Exact steps I used to reproduce the problem (which also results in file corruption, even when reading from the non-snapshot volume). I used a scratch partition, /dev/sda8: ######################################################################## # create the software RAID as a 2 device mirror with 1 missing mdadm -C -l 1 -n 2 /dev/md0 /dev/sda8 missing # create the LVM setup pvcreate /dev/md0 vgcreate lvtest /dev/md0 lvcreate -L100m -n test lvtest # make a filesystem and put some data on it mke2fs -j /dev/lvtest/test mount /dev/lvtest/test /mnt cp --preserve=all -r /boot/* /mnt/ umount /mnt blockdev --flushbufs /dev/lvtest/test # now mount it, create a snapshot, and see the result mount /dev/lvtest/test /mnt lvcreate -s -L10m -n snap /dev/lvtest/test diff -ur /boot /mnt ######################################################################## The output I got from diff was: diff: /mnt/System.map-2.6.10-1.766_FC3: Input/output error and I got a bunch of messages like: attempt to access beyond end of device dm-4: rw=0, want=8300006146, limit=204800 Buffer I/O error on device dm-4, logical block 4150003072 from the kernel. These only seem to appear sometimes - other times I get file corruption (although the corruption appears to be block-aligned). If I then do: ######################################################################## lvremove /dev/lvtest/snap umount /mnt blockdev --flushbufs /dev/lvtest/test mount /dev/lvtest/test /mnt diff -ur /boot /mnt ######################################################################## It compares with no errors. -- Chris Adams Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/