From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?TGFzc2UgS8Okcmtrw6RpbmVu?= Subject: Manually hacking superblocks Date: Fri, 13 Apr 2007 11:11:23 +0300 Message-ID: <461F3B2B.4030006@trn.iki.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids I managed to mess up a RAID-5 array by mdadm -adding a few failed disks back, trying to get the array running again. Unfortunately, -add didn't do what I expected, but instead made spares out of the failed disks. The disks failed due to loose SATA cabling and the data inside should be fairly consistent. sdh failed a bit earlier than sdd and sde, so I expect to be able to revocer by building a degraded array without sdh and then syncing. The current situation looks like this: Number Major Minor RaidDevice State 0 0 8 33 0 active sync /dev/sdc1 1 1 0 0 1 faulty removed 2 2 8 97 2 active sync /dev/sdg1 3 3 8 129 3 active sync /dev/sdi1 4 4 0 0 4 faulty removed 5 5 8 81 5 active sync /dev/sdf1 6 6 0 0 6 faulty removed 7 7 8 177 7 spare 8 8 8 161 8 spare 9 9 8 145 9 spare ... and before any of this happened, the configuration was: disk 0, o:1, dev:sdc1 disk 1, o:1, dev:sde1 disk 2, o:1, dev:sdg1 disk 3, o:1, dev:sdi1 disk 4, o:1, dev:sdh1 disk 5, o:1, dev:sdf1 disk 6, o:1, dev:sdd1 I gather that I need a way to alter the superblocks of sde and sdd so that they seem to be clean up-to-date disks, with their original disk numbers 1 and 6. A hex editor comes to mind, but are there any better tools for that?