Can someone wiser than me help get my RAID5 array back online?
I have a raid 5 array /dev/md0, with 4 300GB disks,
comprising /dev/sda1, /dev/sdb1, /dev/sdc1 & /dev/sdd1. One of the disks
(/dev/sda1) was failed from the array last night. I shut down this morning
expecting to be able to replace the disc, reboot, fdisk /dev/sda1, and
mdadm /dev/md0 --add /dev/sda1. However, the array will not come back online.
It should with 3 original disks out of the 4, right? The array is assembled,
but inactive. If I try to start it....
# mdadm --run /dev/md0
mdadm: failed to run array /dev/md0: Input/output error
Here is some info.......
# cat /proc/mdstat
Personalities : [raid5]
md0 : inactive sdb1[1] sdd1[3] sdc1[2]
879148800 blocks
unused devices: <none>
# mdadm --detail /dev/md0
/dev/md0:
Version : 00.90.03
Creation Time : Sat Feb 18 01:51:12 2006
Raid Level : raid5
Device Size : 293049600 (279.47 GiB 300.08 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Sun Mar 19 11:54:53 2006
State : active, degraded
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 64K
UUID : d72f7bc1:dbf26498:7b3f419f:28ae8a1c
Events : 0.301864
Number Major Minor RaidDevice State
0 0 0 - removed
1 8 17 1 active sync /dev/sdb1
2 8 33 2 active sync /dev/sdc1
3 8 49 3 active sync /dev/sdd1
# mdadm --examine /dev/sdb1
/dev/sdb1:
Magic : a92b4efc
Version : 00.90.03
UUID : d72f7bc1:dbf26498:7b3f419f:28ae8a1c
Creation Time : Sat Feb 18 01:51:12 2006
Raid Level : raid5
Raid Devices : 4
Total Devices : 4
Preferred Minor : 0
Update Time : Sun Mar 19 11:54:53 2006
State : active
Active Devices : 3
Working Devices : 3
Failed Devices : 1
Spare Devices : 0
Checksum : 99cbf09f - correct
Events : 0.301864
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 1 8 17 1 active sync /dev/sdb1
0 0 0 0 0 removed
1 1 8 17 1 active sync /dev/sdb1
2 2 8 33 2 active sync /dev/sdc1
3 3 8 49 3 active sync /dev/sdd1
# mdadm --examine /dev/sdc1
/dev/sdc1:
Magic : a92b4efc
Version : 00.90.03
UUID : d72f7bc1:dbf26498:7b3f419f:28ae8a1c
Creation Time : Sat Feb 18 01:51:12 2006
Raid Level : raid5
Raid Devices : 4
Total Devices : 4
Preferred Minor : 0
Update Time : Sun Mar 19 11:54:53 2006
State : active
Active Devices : 3
Working Devices : 3
Failed Devices : 1
Spare Devices : 0
Checksum : 99cbf0b1 - correct
Events : 0.301864
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 2 8 33 2 active sync /dev/sdc1
0 0 0 0 0 removed
1 1 8 17 1 active sync /dev/sdb1
2 2 8 33 2 active sync /dev/sdc1
3 3 8 49 3 active sync /dev/sdd1
# mdadm --examine /dev/sdd1
/dev/sdd1:
Magic : a92b4efc
Version : 00.90.03
UUID : d72f7bc1:dbf26498:7b3f419f:28ae8a1c
Creation Time : Sat Feb 18 01:51:12 2006
Raid Level : raid5
Raid Devices : 4
Total Devices : 4
Preferred Minor : 0
Update Time : Sun Mar 19 11:54:53 2006
State : active
Active Devices : 3
Working Devices : 3
Failed Devices : 1
Spare Devices : 0
Checksum : 99cbf0c3 - correct
Events : 0.301864
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 3 8 49 3 active sync /dev/sdd1
0 0 0 0 0 removed
1 1 8 17 1 active sync /dev/sdb1
2 2 8 33 2 active sync /dev/sdc1
3 3 8 49 3 active sync /dev/sdd1
Regards
Clive
--
Clive Messer <clive@xxxxxxxxxxxxxxxxx>
