From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Feddern Subject: Raid5 trouble after Upgrade. How to change this magic number in superblock Date: Wed, 09 Apr 2003 12:18:45 +0200 Sender: linux-raid-owner@vger.kernel.org Message-ID: <3E93F385.6090603@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hello there, I got a problem with my raid5. After I updated my linux distribution the following happend: While booting the autoraid process yells at me: md: invalid raid superblock magic on md0 md: md0 has invalid sb, not importing md: no nested devices found md: autorun done raid5: switching cache buffer size, 4096 --> 1024 cat /proc/mdstat looks completly ok lsraid tells me that md0 doesnt have a valid superblock mdadm --examine tells me that the magic number it reads from superblock /dev/md0 is not what was expected. Strangely: The expected magic number is on the superblock of all four raid partitions!!!. They all look like this: /dev/hde1: Magic : a92b4efc Version : 00.90.00 UUID : 05527cce:757e81d8:7476d03f:5bfaaa2b Creation Time : Fri Jun 28 15:32:11 2002 Raid Level : raid5 Device Size : 97685632 (93.16 GiB 100.03 GB) Raid Devices : 3 Total Devices : 4 Preferred Minor : 0 Update Time : Wed Apr 9 12:01:29 2003 State : dirty, no-errors Active Devices : 3 Working Devices : 4 Failed Devices : 0 Spare Devices : 1 Checksum : 75f13011 - correct Events : 0.147 Layout : left-symmetric Chunk Size : 32K Number Major Minor RaidDevice State this 0 33 1 0 active sync /dev/hde1 0 0 33 1 0 active sync /dev/hde1 1 1 33 65 1 active sync /dev/hdf1 2 2 34 1 2 active sync /dev/hdg1 3 3 34 65 3 /dev/hdh1 All deviced show this info. But the md0 superblock seems to have a wrong magic number. I can mount /dev/md0 just fine and also read or modify data. This error message is just making me nervous. Can i change the superblock to the valid values again somehow? If yes how :)? Any1 got an idea ? Thx Christian P.S Here my raidtab file raiddev /dev/md0 raid-level 5 nr-raid-disks 3 nr-spare-disks 1 persistent-superblock 1 parity-algorithm left-symmetric chunk-size 32 device /dev/hde1 raid-disk 0 device /dev/hdf1 raid-disk 1 device /dev/hdg1 raid-disk 2 device /dev/hdh1 spare-disk 0