[SOLVED] linux raid failure

[Vieri]

Hi,

Before I start messing with mdadm I'd like to make sure I do the right thing to check and array and eventually rebuild it without data loss.

mdadm shows the following:

Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath] [faulty]
md1 : active raid1 dm-8[1]
244485120 blocks [2/1] [_U]

md0 : active raid1 dm-1[1] dm-0[0]
104320 blocks [2/2] [UU]

unused devices: <none>

mdadm --examine for sda3 shows this:

/dev/sda3:
Magic : a92b4efc
Version : 00.90.00
UUID : fa73549f:fea4b6f2:4ea64123:b2cb5dc4
Creation Time : Sun Mar 26 13:32:20 2006
Raid Level : raid1
Used Dev Size : 244485120 (233.16 GiB 250.35 GB)
Array Size : 244485120 (233.16 GiB 250.35 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1

Update Time : Sun Apr 21 13:13:09 2013
State : active
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Checksum : 47e266eb - correct
Events : 0.39013


Number Major Minor RaidDevice State
this 0 253 7 0 active sync /dev/mapper/sda3

0 0 253 7 0 active sync /dev/mapper/sda3
1 1 253 8 1 active sync /dev/mapper/sdb3

mdadm --examine sdb3:

/dev/sdb3:
Magic : a92b4efc
Version : 00.90.00
UUID : fa73549f:fea4b6f2:4ea64123:b2cb5dc4
Creation Time : Sun Mar 26 13:32:20 2006
Raid Level : raid1
Used Dev Size : 244485120 (233.16 GiB 250.35 GB)
Array Size : 244485120 (233.16 GiB 250.35 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1

Update Time : Sun May 19 14:06:41 2013
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Checksum : 4807ff51 - correct
Events : 0.40352


Number Major Minor RaidDevice State
this 1 253 8 1 active sync /dev/mapper/sdb3

0 0 0 0 0 removed
1 1 253 8 1 active sync /dev/mapper/sdb3

dmesg doesn't reveal any errors regarding /dev/sda.

Also, /dev/sda1 seems to be ok:

/dev/sda1:
Magic : a92b4efc
Version : 00.90.00
UUID : 9845034b:0951e9ea:f7e4b334:39c9a41c
Creation Time : Sun Mar 26 13:21:50 2006
Raid Level : raid1
Used Dev Size : 104320 (101.89 MiB 106.82 MB)
Array Size : 104320 (101.89 MiB 106.82 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0

Update Time : Sat Jan 26 18:49:43 2013
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Checksum : 119cc0dd - correct
Events : 0.242


Number Major Minor RaidDevice State
this 0 253 0 0 active sync /dev/mapper/sda1

0 0 253 0 0 active sync /dev/mapper/sda1
1 1 253 1 1 active sync /dev/mapper/sdb1

as well as /dev/sdb1:

/dev/sdb1:
Magic : a92b4efc
Version : 00.90.00
UUID : 9845034b:0951e9ea:f7e4b334:39c9a41c
Creation Time : Sun Mar 26 13:21:50 2006
Raid Level : raid1
Used Dev Size : 104320 (101.89 MiB 106.82 MB)
Array Size : 104320 (101.89 MiB 106.82 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0

Update Time : Sat Jan 26 18:49:43 2013
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Checksum : 119cc0e0 - correct
Events : 0.242


Number Major Minor RaidDevice State
this 1 253 1 1 active sync /dev/mapper/sdb1

0 0 253 0 0 active sync /dev/mapper/sda1
1 1 253 1 1 active sync /dev/mapper/sdb1

So, should I consider /dev/sda as a failed disk and physically replace it before re-creating the array?
Or should I make further tests to determine if /dev/sda3 is really flawed or not.
If so, how?

Thanks,

Vieri

[NeddySeagoon]

Vieri,

sda is clearly not stone dead as /dev/sda1 is still a member of md0.

There would have been some valuable information in dmesg about why /dev/sda3 was dropped but I suppose thats gone now.

You may as well add /dev/sda3 back to the raid set and see what happens. The add process will rebuild the raid which will involve a complete write to /dev/sda3. If this fails, dmesg will be informative.

You can also install smartmontools and run smartctl to look at the drives internal error log. If you are going to add /dev/sda3 back to the raid, there is no point in running any of the smartctl tests - the rebuild will do a much better job of testing.

Its worth doing

[Vieri]

Thanks. Sync in progress...