Re: Please Help! RAID5 -> 6 reshapre gone bad

[Richard Herd <2001oddity@xxxxxxxxx>]

Hi Neil,

Thanks.

FYI, I've cloned your git repo and compiled and tried using your code.
 Unfortunately everything looks the same as below (exactly same
output, exactly same dmesg - still wants to kick non-fresh sdc from
the array at assemble).

Cheers

Rich

On Tue, Feb 7, 2012 at 2:10 PM, NeilBrown <neilb@xxxxxxx> wrote:
> On Tue, 7 Feb 2012 13:39:47 +1100 NeilBrown <neilb@xxxxxxx> wrote:
>
>> > I tried to assembe the array, to see if it would continue the reshape:
>> >
>> > root@raven:/# mdadm -Avv --backup-file=/usb/md0.backup /dev/md0
>> > /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sdf1 /dev/sdg1
>> >
>> > Unfortunately mdadm had decided that the backup-file was out of date
>> > (timestamps didn't match) and was erroring with: Failed to restore
>> > critical section for reshape, sorry..
>> >
>> > Chances are things were in such a mess that backup file wasn't going
>> > to be used anyway, so I blocked the timestamp check with: export
>> > MDADM_GROW_ALLOW_OLD=1
>> >
>> > That allowed me to assemble the array, but not run it as there were
>> > not enough disks to start it.
>>
>> You probably just need to add "--force" to the assemble line.
>> So stop the array (mdamd -S /dev/md0) and assemble again with --force as well
>> as the other options.... or maybe don't.
>>
>> I just tested that and I didn't do what it should.  I've hacked the code a
>> bit and can see what the problem is and think I can fix it.
>>
>> So leave it a bit.  I'll let you know when you should  grab my latest code
>> and try that.
>
> Ok, that should work..
> If you:
>
>  git clone git://neil.brown.name/mdadm
>  cd mdadm
>  make
>  export MDADM_GROW_ALLOW_OLD=1
>  ./mdadm -Avv --backup-file=/usb/md0.backup /dev/md0 ..list.of.devices.. --force
>
>
> it should restart the grow.  Once device will be left failed.  If you think
> it is usable then when the grow completes you can add it back in.
>
> If you get another failure it will die again and you'll have to restart it.
>
> If you get a persistent failure, you might be out of luck.
>
> Please let me know how it goes.
>
> NeilBrown
>
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