Re: Recovering RAID5 with 2, actually 1, faulty disks.

[Phil Turmel <philip@turmel.org>]

On 11/25/2015 11:29 AM, Semyon Enskiy wrote:
>>>  Maybe assemble command should include sdj3 device too?
>>>  Like
>>>  # mdadm -v --assemble --update=revert-reshape /dev/md3 /dev/sd[a-j]3
>>>  not
>>>  # mdadm -v --assemble --update=revert-reshape /dev/md3 /dev/sd[a-i]3
>>
>> Yes, my mistake. :-( Try again, including 'sdj3'.
>>
>> Phil
> 
> # mdadm -v --assemble --update=revert-reshape /dev/md3 /dev/sd[a-j]3
> mdadm: looking for devices for /dev/md3
> mdadm: superblock on /dev/sdj3 doesn't match others - assembly aborted
> 
> # mdadm -v --assemble --update=revert-reshape --force /dev/md3 /dev/sd[a-j]3
> mdadm: looking for devices for /dev/md3
> mdadm: superblock on /dev/sdj3 doesn't match others - assembly aborted
> 
> Note, that --examine in previous message shows delta devices value "-1" for
> all members of array, excepting sdj3, which has value "1", without minus
> symbol.

Hmmm. That's interesting.  That means mdadm wrote the revert-reshape
before it finished assembly.  Try this:

mdadm --stop /dev/md3

mdadm --assemble --update=revert-reshape /dev/md3 /dev/sdj3

That should fail w/ not enough to start, but apply the revert to that
one drive.  Then --stop again, and try with [a-j].

Phil