From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bernd Schubert Subject: md3: unsupported reshape (reduce disks) required - aborting Date: Tue, 26 Feb 2008 20:20:12 +0100 Message-ID: <200802262020.12458.bs@q-leap.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hello, while doing a md-check, there was a problem with Lustre and I had to hard-reboot. Please note, the raid was perfectly fine, I only did a manual "echo check >/sys/block/md3/md/sync_action" to increase the load. After the unclean reset/reboot the md devices don't come up, dmesg shows: [ 1169.127975] md: pers->run() failed ... [ 1193.398304] md: md3 stopped. [ 1193.401312] md: unbind [ 1193.404287] md: export_rdev(sdk1) [ 1193.407759] md: unbind [ 1193.410751] md: export_rdev(sdm1) [ 1193.414162] md: unbind [ 1193.417162] md: export_rdev(sdg1) [ 1193.420585] md: unbind [ 1193.423564] md: export_rdev(sdc1) [ 1275.761216] md: md3 stopped. [ 1275.768875] md: bind [ 1275.771869] md: bind [ 1275.775006] md: bind [ 1275.778210] md: bind [ 1275.781219] md: md3: raid array is not clean -- starting background reconstruction [ 1275.792922] raid5: md3: unsupported reshape (reduce disks) required - aborting. mdadm --force --run doesn't help. It also doesn't help to just specifiy 4 of the 6 md devices. The super-block is on all device identical as shown below. As last action I think I can only recreate the array, but I think this is the worst and most dangerous action and IMHO this is a bug. Any idea how to continue without re-creating the array? This is with linux-2.6.22.18 and mdadm v2.5.6 . pfs1n9:~# mdadm --examine /dev/inf/box-6a/1 /dev/inf/box-6a/1: Magic : a92b4efc Version : 00.91.00 UUID : c318c4c3:7c976bfe:da28f9bd:db4d93a0 Creation Time : Wed Jan 2 18:09:05 2008 Raid Level : raid6 Device Size : 1708717056 (1629.56 GiB 1749.73 GB) Array Size : 6834868224 (6518.24 GiB 6998.91 GB) Raid Devices : 6 Total Devices : 6 Preferred Minor : 3 Reshape pos'n : 225878016 (215.41 GiB 231.30 GB) Update Time : Tue Feb 26 19:40:04 2008 State : active Active Devices : 6 Working Devices : 6 Failed Devices : 0 Spare Devices : 0 Checksum : ae7a4ac1 - correct Events : 0.123769 Chunk Size : 1024K Number Major Minor RaidDevice State this 4 8 65 4 active sync /dev/sde1 0 0 8 161 0 active sync /dev/sdk1 1 1 8 33 1 active sync /dev/sdc1 2 2 8 97 2 active sync /dev/sdg1 3 3 8 193 3 active sync /dev/sdm1 4 4 8 65 4 active sync /dev/sde1 5 5 8 129 5 active sync /dev/sdi1 pfs1n9:~# Thanks in advance, Bernd -- Bernd Schubert Q-Leap Networks GmbH