RAID10 Recovery Issue - mdadm segfault

[marc2112]

Hi folks,

I have a 4 disk software RAID10 that's not doing too well. 2 of 4 disks lost power and are flagged as "faulty removed". Now that the power is restored, I feel like there should be a way to force the array back together but all the usual commands aren't working.

Here you can see the output of the commands I ran. Any thoughts on how to recover?

http://pastebin.com/m1dedbbac

Thanks!
---Marc

[marc2112]

Added output of fdisk -l to pastebin: http://pastebin.com/m39890121

[fjgaude]

Hard to say what is going on with your raid10 array. Seems that sdd6 and sde6 have issues.

One thing you could try is using mdadm to fault and remove each partition, then zero their superblocks and then add the two partitions back into the array.

I guess you don't have backups for important data that's on these partitions, eh?

Read the man pages regarding my suggestion.

Let us know what you decide and the results, thanks.

[marc2112]

Finally got this to work! The mdadm command I had issued originally to force assemble which was producing a segfault works with the 2.6.8 version of mdadm (2.6.7 is shipped with xubuntu 8.10)

root@mclovin:~# /usr/src/mdadm-2.6.8/mdadm --assemble --force /dev/md0 /dev/sd[bcde]6
mdadm: forcing event count in /dev/sdd6(2) from 12547691 upto 12551546
mdadm: forcing event count in /dev/sde6(3) from 12547691 upto 12551546
mdadm: clearing FAULTY flag for device 2 in /dev/md0 for /dev/sdd6
mdadm: clearing FAULTY flag for device 3 in /dev/md0 for /dev/sde6
mdadm: /dev/md0 has been started with 4 drives.


---Marc

[fjgaude]

Interesting... anyway, happy you have the array up again.