Re: mdadm creates corrupt superblock

[Hans Kraus <hans@hanswkraus.com>]

Hi,

I think I found the problem. 'badblocks' reports sector 64 of the HD as
errornous. But the HD neither reports a read error nor remaps that
sector.

Is it possible to parametrize mdadm that it doesn't use that sector?

Regards, Hans

Am 29.10.2014 22:11, schrieb Hans Kraus:
> Hi Neil,
>
> many thanks for your response. I rebooted the machine and got new drive
> assignments. The drive in question is now sdc1. mdadm gave an error with
> the dump, results below (nothing to report by dmesg) [by the way, I
> wasn'nt even able to create an array on that drive with
> 'mdadm --create --level=1 -n 2 /dev/sdc1 missing', same error(s)]:
> -------------------------------------------------------------------------
> root@nashorn:~# mdadm -E /dev/sdb1
> /dev/sdb1:
>            Magic : a92b4efc
>          Version : 1.2
>      Feature Map : 0x1
>       Array UUID : e7caa5d1:b33fd2a5:7782fb0c:9d8d9d5b
>             Name : nashorn:126  (local to host nashorn)
>    Creation Time : Mon Oct 27 15:58:38 2014
>       Raid Level : raid1
>     Raid Devices : 2
>
>   Avail Dev Size : 1953260976 (931.39 GiB 1000.07 GB)
>       Array Size : 976630488 (931.39 GiB 1000.07 GB)
>      Data Offset : 262144 sectors
>     Super Offset : 8 sectors
>     Unused Space : before=262056 sectors, after=0 sectors
>            State : clean
>      Device UUID : f7a91c46:e4cda0c0:1b770fd7:876634f8
>
> Internal Bitmap : 8 sectors from superblock
>      Update Time : Wed Oct 29 18:42:16 2014
>    Bad Block Log : 512 entries available at offset 72 sectors
>         Checksum : 939b22d1 - correct
>           Events : 3325
>
>
>     Device Role : Active device 0
>     Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
> root@nashorn:~#
> -------------------------------------------------------------------------
> root@nashorn:~# mdadm -E /dev/sdh1
> /dev/sdh1:
>            Magic : a92b4efc
>          Version : 1.2
>      Feature Map : 0x1
>       Array UUID : e7caa5d1:b33fd2a5:7782fb0c:9d8d9d5b
>             Name : nashorn:126  (local to host nashorn)
>    Creation Time : Mon Oct 27 15:58:38 2014
>       Raid Level : raid1
>     Raid Devices : 2
>
>   Avail Dev Size : 1953260976 (931.39 GiB 1000.07 GB)
>       Array Size : 976630488 (931.39 GiB 1000.07 GB)
>      Data Offset : 262144 sectors
>     Super Offset : 8 sectors
>     Unused Space : before=262046 sectors, after=0 sectors
>            State : clean
>      Device UUID : 089d1d0e:4d5ca222:dd716acb:0813815c
>
> Internal Bitmap : 8 sectors from superblock
>      Update Time : Wed Oct 29 18:42:16 2014
>    Bad Block Log : 512 entries available at offset 82 sectors
>         Checksum : 16454b96 - correct
>           Events : 3325
>
>
>     Device Role : Active device 1
>     Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
> root@nashorn:~#
> -------------------------------------------------------------------------
> root@nashorn:~# mdadm -E /dev/sdc1
> /dev/sdc1:
>            Magic : a92b4efc
>          Version : 1.2
>      Feature Map : 0x1
>       Array UUID : e7caa5d1:b33fd2a5:7782fb0c:9d8d9d5b
>             Name : nashorn:126  (local to host nashorn)
>    Creation Time : Mon Oct 27 15:58:38 2014
>       Raid Level : raid1
>     Raid Devices : 2
>
>   Avail Dev Size : 1953260976 (931.39 GiB 1000.07 GB)
>       Array Size : 0
>    Used Dev Size : 0
>      Data Offset : 262144 sectors
>     Super Offset : 8 sectors
>     Unused Space : before=262056 sectors, after=1953260976 sectors
>            State : clean
>      Device UUID : 4d1420c6:79978477:e86412b1:24beebfc
>
> Internal Bitmap : 8 sectors from superblock
>      Update Time : Tue Oct 28 11:53:49 2014
>    Bad Block Log : 512 entries available at offset 72 sectors
>         Checksum : 6f02d040 - expected 891eedff
>           Events : 0
>
>
>     Device Role : spare
>     Array State : RR ('A' == active, '.' == missing, 'R' == replacing)
> -------------------------------------------------------------------------
> root@nashorn:~# mkdir -p /tmp/dump
> root@nashorn:~# mdadm --dump /tmp/dump /dev/sdc1
> mdadm: Failed to copy metadata from /dev/sdc1 to /tmp/dump/sdc1
> -------------------------------------------------------------------------
> Kind regards, Hans
>
> Am 28.10.2014 22:00, schrieb NeilBrown:
>> On Tue, 28 Oct 2014 19:06:20 +0100 Hans Kraus <hans@hanswkraus.com>
>> wrote:
>>
>>> Hi,
>>>
>>> I debugged my problem a bit more: it seems that mdadm creates a defect
>>> superblock. That's repeatedly happening, but only for one drive. I
>>> copied zeros to that drive (via ddrescue /dev/zero ...) and the drive
>>> looks OK. The info I got:
>>>
>>
>> and you send me the metadata of all your devices please?
>>
>>     mkdir /tmp/dump
>>     mdadm --dump /tmp/dump /dev/sde1
>>     tar czvf /tmp/dump.tgz /tmp/dump
>>
>> and then send /tmp/dump.tgz
>>
>> Thanks.
>>
>> NeilBrown
>>
>> =================================================================================================================================================================================================
>>
>>> root@nashorn:/home/kraush/work/smartctrl# mdadm --zero-superblock
>>> /dev/sde1
>>> mdadm: Unrecognised md component device - /dev/sde1
>>> root@nashorn:/home/kraush/work/smartctrl# mdadm --add /dev/md126
>>> /dev/sde1
>>> mdadm: add new device failed for /dev/sde1 as 4: Invalid argument
>>> root@nashorn:/home/kraush/work/smartctrl# mdadm -E /dev/sde1
>>> /dev/sde1:
>>>             Magic : a92b4efc
>>>           Version : 1.2
>>>       Feature Map : 0x1
>>>        Array UUID : e7caa5d1:b33fd2a5:7782fb0c:9d8d9d5b
>>>              Name : nashorn:126  (local to host nashorn)
>>>     Creation Time : Mon Oct 27 15:58:38 2014
>>>        Raid Level : raid1
>>>      Raid Devices : 2
>>>
>>>    Avail Dev Size : 1953260976 (931.39 GiB 1000.07 GB)
>>>        Array Size : 0
>>>     Used Dev Size : 0
>>>       Data Offset : 262144 sectors
>>>      Super Offset : 8 sectors
>>>      Unused Space : before=262056 sectors, after=1953260976 sectors
>>>             State : clean
>>>       Device UUID : 4d1420c6:79978477:e86412b1:24beebfc
>>>
>>> Internal Bitmap : 8 sectors from superblock
>>>       Update Time : Tue Oct 28 11:53:49 2014
>>>     Bad Block Log : 512 entries available at offset 72 sectors
>>>          Checksum : 6f02d040 - expected 891eedff
>>>            Events : 0
>>>
>>>
>>>      Device Role : spare
>>>      Array State : RR ('A' == active, '.' == missing, 'R' == replacing)
>>> root@nashorn:/home/kraush/work/smartctrl#
>>> -----------------------------------------------------------------------------------------------------------
>>>
>>> root@nashorn:/home/kraush/work/smartctrl# cat /proc/mdstat
>>> Personalities : [raid1] [raid6] [raid5] [raid4]
>>> md127 : active (auto-read-only) raid6 sda1[0] sdk1[6](S) sdl2[7](S)
>>> sdh1[5] sdg1[4] sdf1[3] sdc1[2] sdb1[1]
>>>         1953017856 blocks super 1.2 level 6, 512k chunk, algorithm 2
>>> [6/6] [UUUUUU]
>>>         bitmap: 0/4 pages [0KB], 65536KB chunk
>>>
>>> md10 : active (auto-read-only) raid1 sdi2[0] sdl3[1]
>>>         87833408 blocks super 1.2 [2/2] [UU]
>>>         bitmap: 0/1 pages [0KB], 65536KB chunk
>>>
>>> md126 : active raid1 sdd1[3] sdj1[2]
>>>         488254464 blocks super 1.2 [2/2] [UU]
>>>         bitmap: 0/4 pages [0KB], 65536KB chunk
>>>
>>> md0 : active raid1 sdl1[4] sdd2[3] sdi1[5]
>>>         156157824 blocks super 1.2 [3/1] [U__]
>>>         [===================>.]  recovery = 95.6% (149290048/156157824)
>>> finish=8.4min speed=13496K/sec
>>>         bitmap: 1/2 pages [4KB], 65536KB chunk
>>>
>>> unused devices: <none>
>>> root@nashorn:/home/kraush/work/smartctrl#
>>> -----------------------------------------------------------------------------------------------------------
>>>
>>> dmesg:
>>> [33299.387382] md: invalid superblock checksum on sde1
>>> [33299.387385] md: sde1 does not have a valid v1.2 superblock, not
>>> importing!
>>> [33299.387408] md: md_import_device returned -22
>>> root@nashorn:/home/kraush/work/smartctrl#
>>> -----------------------------------------------------------------------------------------------------------
>>>
>>> root@nashorn:/home/kraush/work/mdadm# mdadm --version
>>> mdadm - v3.3-161-gfed12d4 - 21st August 2014
>>> =================================================================================================================================================================================================
>>>
>>>
>>> Kind regards, Hans
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>>
>
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