Hello, I have a client with a failed raid5 that is in desperate need of the data that's on the raid. The attached file holds the mdadm -E superblocks that are hopefully the keys to the puzzle. Linux-raid folks, if you can give any help here it would be much appreciated. # mdadm -V mdadm - v1.7.0 - 11 August 2004 # uname -a Linux hazel 2.6.13-gentoo-r5 #1 SMP Sat Jan 21 13:24:15 PST 2006 i686 Intel(R) Pentium(R) 4 CPU 2.40GHz GenuineIntel GNU/Linux Here's my take: Logfiles show that last night drive /dev/etherd/e0.4 failed and around noon today /dev/etherd/e0.0 failed. This jibes with the superblock dates and info. My assessment is that since the last known good configuration was 0 <missing> 1 /dev/etherd/e0.0 2 /dev/etherd/e0.2 3 /dev/etherd/e0.3 then we should shoot for this. I couldn't figure out how to get there using mdadm -A since /dev/etherd/e0.0 isn't in sync with e0.2 or e0.3. If anyone can suggest a way to get this back using -A, please chime in. The alternative is to recreate the array with this configuration hoping the data blocks will all line up properly so the filesystem can be mounted and data retrieved. It looks like the following command is the right way to do this, but not being an expert I (and the client) would like someone else to verify the sanity of this approach. Will mdadm -C /dev/md0 -n 4 -l 5 missing /dev/etherd/e0.[023] do what we want? Linux-raid folks, please reply-to-all as we're probably all not on the list. Thanks for your help, Sam
/dev/etherd/e0.0: Magic : a92b4efc Version : 00.90.00 UUID : 8fe1fe85:eeb90460:c525faab:cdaab792 Creation Time : Mon Jan 3 03:16:48 2005 Raid Level : raid5 Device Size : 195360896 (186.31 GiB 200.05 GB) Raid Devices : 4 Total Devices : 5 Preferred Minor : 0 Update Time : Fri Apr 21 12:45:07 2006 State : clean Active Devices : 3 Working Devices : 4 Failed Devices : 1 Spare Devices : 1 Checksum : 4cc955da - correct Events : 0.3488315 Layout : left-asymmetric Chunk Size : 32K Number Major Minor RaidDevice State this 1 152 0 1 active sync /dev/etherd/e0.0 0 0 0 0 0 removed 1 1 152 0 1 active sync /dev/etherd/e0.0 2 2 152 32 2 active sync /dev/etherd/e0.2 3 3 152 48 3 active sync /dev/etherd/e0.3 4 4 152 16 0 spare /dev/etherd/e0.1 /dev/etherd/e0.2: Magic : a92b4efc Version : 00.90.00 UUID : 8fe1fe85:eeb90460:c525faab:cdaab792 Creation Time : Mon Jan 3 03:16:48 2005 Raid Level : raid5 Device Size : 195360896 (186.31 GiB 200.05 GB) Raid Devices : 4 Total Devices : 5 Preferred Minor : 0 Update Time : Fri Apr 21 14:03:12 2006 State : clean Active Devices : 2 Working Devices : 3 Failed Devices : 3 Spare Devices : 1 Checksum : 4cc991e9 - correct Events : 0.3493633 Layout : left-asymmetric Chunk Size : 32K Number Major Minor RaidDevice State this 2 152 32 2 active sync /dev/etherd/e0.2 0 0 0 0 0 removed 1 1 0 0 1 faulty removed 2 2 152 32 2 active sync /dev/etherd/e0.2 3 3 152 48 3 active sync /dev/etherd/e0.3 4 4 152 16 4 spare /dev/etherd/e0.1 /dev/etherd/e0.3: Magic : a92b4efc Version : 00.90.00 UUID : 8fe1fe85:eeb90460:c525faab:cdaab792 Creation Time : Mon Jan 3 03:16:48 2005 Raid Level : raid5 Device Size : 195360896 (186.31 GiB 200.05 GB) Raid Devices : 4 Total Devices : 5 Preferred Minor : 0 Update Time : Fri Apr 21 14:03:12 2006 State : clean Active Devices : 2 Working Devices : 3 Failed Devices : 3 Spare Devices : 1 Checksum : 4cc991fb - correct Events : 0.3493633 Layout : left-asymmetric Chunk Size : 32K Number Major Minor RaidDevice State this 3 152 48 3 active sync /dev/etherd/e0.3 0 0 0 0 0 removed 1 1 0 0 1 faulty removed 2 2 152 32 2 active sync /dev/etherd/e0.2 3 3 152 48 3 active sync /dev/etherd/e0.3 4 4 152 16 4 spare /dev/etherd/e0.1 /dev/etherd/e0.4: Magic : a92b4efc Version : 00.90.00 UUID : 8fe1fe85:eeb90460:c525faab:cdaab792 Creation Time : Mon Jan 3 03:16:48 2005 Raid Level : raid5 Device Size : 195360896 (186.31 GiB 200.05 GB) Raid Devices : 4 Total Devices : 5 Preferred Minor : 0 Update Time : Thu Apr 20 21:07:50 2006 State : clean Active Devices : 4 Working Devices : 5 Failed Devices : 0 Spare Devices : 1 Checksum : 4cc84d59 - correct Events : 0.3482550 Layout : left-asymmetric Chunk Size : 32K Number Major Minor RaidDevice State this 0 152 64 0 active sync /dev/etherd/e0.4 0 0 152 64 0 active sync /dev/etherd/e0.4 1 1 152 0 1 active sync /dev/etherd/e0.0 2 2 152 32 2 active sync /dev/etherd/e0.2 3 3 152 48 3 active sync /dev/etherd/e0.3 4 4 152 16 4 spare /dev/etherd/e0.1