On Sat, 12 Nov 2011 21:56:56 -0500 Travis Brown <teb@xxxxxxxxxx> wrote:
> I was reshaping my 5 drive raid 5 with spare to a raid 6 array when the drive I was using for my backup went offline. If that's not murphy's law, I don't know what is. The array is still up and usable, but I'm afraid to reboot or doing anything to it, really. Suggestions on getting this thing back to usable are very welcome.
>
> Thanks,
> Travis
>
> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
> md126 : active raid6 sde3[0] sdf3[3] sdb3[1] sdd3[4] sdc3[2]
> 5856728064 blocks super 0.91 level 6, 512k chunk, algorithm 18 [5/4] [UUUU_]
> [>....................] reshape = 0.9% (19267584/1952242688) finish=623878.3min speed=51K/sec
1/ Don't Panic.
You seem to have achieved this step quite effectively - congratulations.
2/ Stop the array cleanly. Not having a backup will only cause possible
corruption if the machine crashes while the reshape is happening. The
reshape has stopped so there is no chance for corruption. But you still
need to cleanly stop the array.
(A subsequent version of mdadm may allow you to continue the reshape
without the stop/restart step, but we aren't there yet).
3/ Make sure you have a version of mdadm which is at least 3.2. I would
suggest the latest:3.2.2. You particularly need the --invalid-backup
flag.
4/ Reassemble the array with e.g.
mdadm --assemble /dev/md126 --backup=/some/file \
--invalid-backup /dev/sd[bcdef]3
The backup file does not need to exist (I think). Maybe create an empty
file and use that just to be safe.
The "--invalid-backup" flag says to mdadm "Yes, I know the backup file is
currently invalid and you cannot restore anything from it. I happen to
know that there is no need to restore anything because I did a clean
shutdown. Just use the backup file for making new backups as you continue
the reshape".
NeilBrown
>
> /dev/md126:
> Version : 0.91
> Creation Time : Wed Nov 10 20:19:03 2010
> Raid Level : raid6
> Array Size : 5856728064 (5585.41 GiB 5997.29 GB)
> Used Dev Size : 1952242688 (1861.80 GiB 1999.10 GB)
> Raid Devices : 5
> Total Devices : 5
> Preferred Minor : 126
> Persistence : Superblock is persistent
>
> Update Time : Sat Nov 12 21:55:46 2011
> State : clean, degraded, recovering
> Active Devices : 4
> Working Devices : 5
> Failed Devices : 0
> Spare Devices : 1
>
> Layout : left-symmetric-6
> Chunk Size : 512K
>
> Reshape Status : 0% complete
> New Layout : left-symmetric
>
> UUID : 3fd8b303:7727aa3b:c5d110f2:f9137e1d
> Events : 0.124051
>
> Number Major Minor RaidDevice State
> 0 8 67 0 active sync /dev/sde3
> 1 8 19 1 active sync /dev/sdb3
> 2 8 35 2 active sync /dev/sdc3
> 3 8 83 3 active sync /dev/sdf3
> 4 8 51 4 spare rebuilding /dev/sdd3--
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Attachment:
signature.asc
Description: PGP signature
