Hi
I'm having a problem with a 4 disk Raid 5 MD-Array.
After a crash it didn't reassemble correctly, by that I mean it crashed
during the reassemble, and cat /proc/mdstat reads as follows:
[root@dirvish ~]# cat /proc/mdstat
Personalities : [raid1] [raid0] [raid6] [raid5] [raid4]
...
md3 : inactive sdd1[0] sde1[5] sdf1[3] sdc1[2]
7814047744 blocks
...
mdadm --examine for the disks in the Raid reads as follows:
[root@dirvish ~]# mdadm -E /dev/sdc1
/dev/sdc1:
Magic : a92b4efc
Version : 0.90.00
UUID : 84b70068:58203635:60d8aaf0:b60ee018
Creation Time : Mon Feb 28 18:46:58 2011
Raid Level : raid5
Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
Raid Devices : 4
Total Devices : 4
Preferred Minor : 3
Update Time : Wed Jan 8 12:26:35 2020
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 1
Spare Devices : 1
Checksum : bd93dda1 - correct
Events : 5995154
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 2 8 33 2 active sync /dev/sdc1
0 0 8 49 0 active sync /dev/sdd1
1 1 0 0 1 faulty removed
2 2 8 33 2 active sync /dev/sdc1
3 3 8 81 3 active sync /dev/sdf1
4 4 8 65 4 spare /dev/sde1
[root@dirvish ~]# mdadm -E /dev/sdd1
/dev/sdd1:
Magic : a92b4efc
Version : 0.90.00
UUID : 84b70068:58203635:60d8aaf0:b60ee018
Creation Time : Mon Feb 28 18:46:58 2011
Raid Level : raid5
Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 3
Update Time : Wed Jan 8 13:30:15 2020
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 2
Spare Devices : 0
Checksum : bd93ec60 - correct
Events : 5995162
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 0 8 49 0 active sync /dev/sdd1
0 0 8 49 0 active sync /dev/sdd1
1 1 0 0 1 faulty removed
2 2 0 0 2 faulty removed
3 3 8 81 3 active sync /dev/sdf1
[root@dirvish ~]# mdadm -E /dev/sde1
/dev/sde1:
Magic : a92b4efc
Version : 0.90.00
UUID : 84b70068:58203635:60d8aaf0:b60ee018
Creation Time : Mon Feb 28 18:46:58 2011
Raid Level : raid5
Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 3
Update Time : Wed Jan 8 13:30:15 2020
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 2
Spare Devices : 0
Checksum : bd93ecbd - correct
Events : 5995162
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 5 8 65 -1 spare /dev/sde1
0 0 8 49 0 active sync /dev/sdd1
1 1 0 0 1 faulty removed
2 2 0 0 2 faulty removed
3 3 8 81 3 active sync /dev/sdf1
[root@dirvish ~]# mdadm -E /dev/sdf1
/dev/sdf1:
Magic : a92b4efc
Version : 0.90.00
UUID : 84b70068:58203635:60d8aaf0:b60ee018
Creation Time : Mon Feb 28 18:46:58 2011
Raid Level : raid5
Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 3
Update Time : Wed Jan 8 13:30:15 2020
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 2
Spare Devices : 0
Checksum : bd93ec86 - correct
Events : 5995162
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 3 8 81 3 active sync /dev/sdf1
0 0 8 49 0 active sync /dev/sdd1
1 1 0 0 1 faulty removed
2 2 0 0 2 faulty removed
3 3 8 81 3 active sync /dev/sdf1
My plan now would be to run mdadm --assemble --force /dev/md3 with 3
disk, to get the Raid going in a degraded state.
Does anyone have any experience in doing so and can recommend which 3
disks I should use. I would use sdc1 sdd1 and sdf1, since sdd1 and sdf1
are displayed as active sync in every examine and sdc1 as it is also
displayed as active sync.
Do you think that by doing it this way I have a chance to get my Data
back or do you have any other suggestion as to get the Data back and the
Raid running again?
Greetings
Christian
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