On Monday, January 14, 2013 4:25 PM chris [off-list ref] wrote:

Ok thanks for the tips, I am imaging the disks now and will try after
that is done. Just out of curiousity what could become corrupted by
forcing the assemble? I was under the impression that as long as I
have one member missing that the only thing that would be touched is
metadata, is that right?

Yes, that is right. I meant that using --force option it may be possible to assembly an array in the wrong way and data can be incorrect, so it is better to be careful.

Lukasz

On Mon, Jan 14, 2013 at 9:24 AM, Dorau, Lukasz [off-list ref]
wrote:

quoted

On Monday, January 14, 2013 3:11 PM Dorau, Lukasz

[off-list ref] wrote:

quoted

quoted

On Monday, January 14, 2013 1:56 AM chris [off-list ref] wrote:

quoted

[292295.923942] bio: create slab <bio-1> at 1
[292295.923965] md/raid:md126: not clean -- starting background
reconstruction
[292295.924000] md/raid:md126: device sdb operational as raid disk 2
[292295.924005] md/raid:md126: device sdc operational as raid disk 1
[292295.924009] md/raid:md126: device sde operational as raid disk 0
[292295.925149] md/raid:md126: allocated 4250kB
[292295.927268] md/raid:md126: cannot start dirty degraded array.

Hi

*Remember to backup the disks you have before trying the following! *

You can try starting dirty degraded array using:
#  mdadm --assemble --force ....

I meant adding --force option to:
# mdadm --create --verbose --force /dev/md/Volume0 /dev/sdc missing

/dev/sdb /dev/sdd --raid-devices 4 --level=5

quoted

Be very careful using "--force" option, because it can cause data corruption!

Lukasz

quoted

See also the "Boot time assembly of degraded/dirty arrays" chapter in:
http://www.kernel.org/doc/Documentation/md.txt
(you can boot with option md-mod.start_dirty_degraded=1)

Lukasz

quoted

[292295.929666] RAID conf printout:
[292295.929677]  --- level:5 rd:4 wd:3
[292295.929683]  disk 0, o:1, dev:sde
[292295.929688]  disk 1, o:1, dev:sdc
[292295.929693]  disk 2, o:1, dev:sdb
[292295.930898] md/raid:md126: failed to run raid set.
[292295.930902] md: pers->run() failed ...
[292295.931079] md: md126 stopped.
[292295.931096] md: unbind<sdb>
[292295.944228] md: export_rdev(sdb)
[292295.944267] md: unbind<sdc>
[292295.958126] md: export_rdev(sdc)
[292295.958167] md: unbind<sde>
[292295.970902] md: export_rdev(sde)
[292296.219837] device-mapper: table: 252:1: raid45: unknown target type
[292296.219845] device-mapper: ioctl: error adding target to table
[292296.291542] device-mapper: table: 252:1: raid45: unknown target type
[292296.291548] device-mapper: ioctl: error adding target to table
[292296.310926] quiet_error: 1116 callbacks suppressed
[292296.310934] Buffer I/O error on device dm-0, logical block

3907022720

quoted

quoted

quoted

[292296.310940] Buffer I/O error on device dm-0, logical block

3907022721

quoted

quoted

quoted

[292296.310944] Buffer I/O error on device dm-0, logical block

3907022722

quoted

quoted

quoted

[292296.310949] Buffer I/O error on device dm-0, logical block

3907022723

quoted

quoted

quoted

[292296.310953] Buffer I/O error on device dm-0, logical block

3907022724

quoted

quoted

quoted

[292296.310958] Buffer I/O error on device dm-0, logical block

3907022725

quoted

quoted

quoted

[292296.310962] Buffer I/O error on device dm-0, logical block

3907022726

quoted

quoted

quoted

[292296.310966] Buffer I/O error on device dm-0, logical block

3907022727

quoted

quoted

quoted

[292296.310973] Buffer I/O error on device dm-0, logical block

3907022720

quoted

quoted

quoted

[292296.310977] Buffer I/O error on device dm-0, logical block

3907022721

quoted

quoted

quoted

[292296.319968] device-mapper: table: 252:1: raid45: unknown target type
[292296.319975] device-mapper: ioctl: error adding target to table

Any ideas from here? Am I up the creek without a paddle? :(

thanks to everyone for all your help so far
chris

On Sun, Jan 13, 2013 at 4:05 PM, Dan Williams [off-list ref] wrote:

quoted

On 1/13/13 11:00 AM, "chris" [off-list ref] wrote:

quoted

Neil/Dave,

Is it not possible to create imsm container with missing disk?
If not, Is there any way to recreate the array with all disks but
prevent any kind of sync which may overwrite array data?

The example was in that link I sent:

mdadm --create /dev/md/imsm /dev/sd[bde] -e imsm
mdadm --create /dev/md/vol0 /dev/sde missing /dev/sdb /dev/sdd -n 4 -l

5

quoted

quoted

quoted

quoted

The first command marks all devices as spares.  The second creates the
degraded array.

You probably want at least sdb and sdd in there since they have a copy of
the metadata.

--
Dan

--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html