* Re: Failed RAID6
2012-02-24 17:56 ` Failed RAID6 Larry Owen
@ 2012-02-24 20:52 ` NeilBrown
0 siblings, 0 replies; 2+ messages in thread
From: NeilBrown @ 2012-02-24 20:52 UTC (permalink / raw)
To: Larry Owen; +Cc: linux-raid
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On Fri, 24 Feb 2012 11:56:39 -0600 (CST) Larry Owen <larryowen@cis.uab.edu>
wrote:
> We have a raid6 array with 3 "failed" discs. However, smart
> status for all drives is ok. I'm also not seeing any io errors
> in my logs (except when the discs were initially dropped). I
> also tried reading raw data from one of the failed drives,
> using dd. I was able to get data, still no io errors.
>
> We're thinking about trying to re-add or assemble --force,
> in hopes of getting it up to recover some data (did I mention
> the users put important data on here knowing it was not backed
> up).
>
> Our main concern is that we add the discs and the system start
> rebuilding. Any suggestions on how we should proceed?
Use assemble --force - this situation is exactly what it is for.
mdadm -S /dev/md0
mdadm -A --force /dev/md0
You might need to list all the component devices, depending on what is in
your mdadm.conf
NeilBrown
>
> Thanks,
> Larry Owen
>
> ################### MDADM OUTPUT ##############################
>
> mdadm --detail /dev/md0
> /dev/md0:
> Version : 1.2
> Creation Time : Tue Feb 1 16:25:03 2011
> Raid Level : raid6
> Used Dev Size : 1953512960 (1863.02 GiB 2000.40 GB)
> Raid Devices : 22
> Total Devices : 21
> Persistence : Superblock is persistent
>
> Update Time : Wed Feb 22 23:42:11 2012
> State : active, FAILED, Not Started
> Active Devices : 19
> Working Devices : 21
> Failed Devices : 0
> Spare Devices : 2
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Name : kddm-nas:0 (local to host kddm-nas)
> UUID : 9fc31e38:7723974a:1f37af62:5a75ec91
> Events : 5412
>
> Number Major Minor RaidDevice State
> 0 8 16 0 active sync /dev/sdb
> 1 8 32 1 active sync /dev/sdc
> 2 8 48 2 active sync /dev/sdd
> 3 8 64 3 active sync /dev/sde
> 4 8 80 4 active sync /dev/sdf
> 5 8 96 5 active sync /dev/sdg
> 6 8 112 6 active sync /dev/sdh
> 7 0 0 7 removed
> 8 8 144 8 active sync /dev/sdj
> 9 8 160 9 active sync /dev/sdk
> 10 8 176 10 active sync /dev/sdl
> 11 0 0 11 removed
> 12 8 208 12 active sync /dev/sdn
> 13 8 224 13 active sync /dev/sdo
> 14 8 240 14 active sync /dev/sdp
> 15 0 0 15 removed
> 16 65 16 16 active sync /dev/sdr
> 17 65 32 17 active sync /dev/sds
> 18 65 48 18 active sync /dev/sdt
> 19 65 64 19 active sync /dev/sdu
> 20 65 80 20 active sync /dev/sdv
> 21 65 96 21 active sync /dev/sdw
>
> 22 65 112 - spare /dev/sdx
> 23 65 128 - spare /dev/sdy
>
>
>
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