From: Joe Landman <landman@scalableinformatics.com>
To: Mike Berger <lists@mike01.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: RAID 5 Recovery Help Needed
Date: Fri, 16 Jan 2009 15:42:59 -0500 [thread overview]
Message-ID: <4970F153.30106@scalableinformatics.com> (raw)
In-Reply-To: <4970E18C.2000100@mike01.com>
Mike Berger wrote:
> Created the array:
> # mdadm --create --verbose /dev/md0 --level=5 --chunk=128
> --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1
eek ... a RAID5 on 3 drives?
Did you do an
mdadm --detail --scan > /etc/mdadm.conf
after this?
[...]
> At this point I used the newly created array for a few days without any
> issues at all.
... but did you update mdadm.conf as above?
[...]
> Now I tried to assemble the array manually using the following commands,
> all of which failed (note that I had never edited mdadm.conf).
>
> # mdadm --assemble --scan
This generally requires an /etc/mdadm.conf (or similar
/etc/mdadm/mdadm.conf)
> # mdadm --assemble --scan --uuid=3128da32:c5e4ff31:b43fc0e6:226924cf
> # mdadm --assemble /dev/md0 /dev/sdb1 /dev/sdc1 /dev/sdd1
> # mdadm --assemble -f /dev/md0 /dev/sdb1 /dev/sdc1 /dev/sdd1
> # mdadm --assemble --uuid=3128da32:c5e4ff31:b43fc0e6:226924cf /dev/md0
> /dev/sdb1 /dev/sdc1 /dev/sdd1
You can often (re)construct this file if you forget to create it with a
little detective work ...
mdadm --examine /dev/sdb1
could be your friend.
[...]
> # fsck.ext4 -n /dev/md0
>
> I get:
>
> fsck.ext4: Superblock invalid, trying backup blocks...
> fsck.ext4: Bad magic number in super-block while trying to open /dev/md0
>
> I've tried specifying the blocksize and specifying the superblock
> manually using the backup superblocks from when I ran mkfs.ext4, but
> get the same result. I haven't dared to run fsck without -n until I
> hear from someone more knowledged.
>
> So, if anyone has any suggestions on how I can get md0 mounted or
> recover my data it would be much appreciated.
I am not completely sure, but I would bet that with the changes you have
made, that this data may not be recoverable at this point.
Before you do anything else, I would definitely suggest creating the
mdadm.conf file properly as noted above.
Joe
--
Joe Landman
Scalable Informatics LLC,
email: landman@scalableinformatics.com
web : http://www.scalableinformatics.com
next prev parent reply other threads:[~2009-01-16 20:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-16 19:35 RAID 5 Recovery Help Needed Mike Berger
2009-01-16 20:42 ` Joe Landman [this message]
2009-01-16 21:09 ` Mike Berger
[not found] ` <49722439.3060103@tmr.com>
2009-01-17 18:51 ` Mike Berger
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