From: NeilBrown <neilb@suse.de>
To: Alexander Schleifer <alexander.schleifer@googlemail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: RAID5 superblock and filesystem recovery after re-creation
Date: Mon, 9 Jul 2012 08:13:58 +1000 [thread overview]
Message-ID: <20120709081358.199630c8@notabene.brown> (raw)
In-Reply-To: <CA+=meHXO02k4hSJihNFiYXb+LOjik_LX3n8UZbqERC2tYy+L-g@mail.gmail.com>
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On Sun, 8 Jul 2012 23:47:16 +0200 Alexander Schleifer
<alexander.schleifer@googlemail.com> wrote:
> Hi,
>
> after a new installation of Ubuntu, my RAID5 device was set to
> "inactive". All devices were set to spare device and the level was
> unknown. So I tried to re-create the array by the following command.
Sorry about that. In case you haven't seen it,
http://neil.brown.name/blog/20120615073245
explains the background
>
> mdadm --create /dev/md0 --assume-clean --level=5 --raid-disk=6
> --chunk=512 --metadata=1.2 /dev/sde /dev/sdd /dev/sda /dev/sdc
> /dev/sdg /dev/sdh
>
> I have a backup of the mdadm -Evvvvs output, so I could recover the
> chunk size, metadata and offset (2048) from this information.
>
> The partially output of mdadm --create... shows this output:
>
> ...
> mdadm: /dev/sde appears to be part of a raid array:
> level=raid5 devices=6 ctime=Sun Jul 8 23:02:51 2012
> mdadm: partition table exists on /dev/sde but will be lost or
> meaningless after creating array
> ...
>
> The array is recreated, but no valid filesystem is found on /dev/md0
> (dumpe2fs: Filesystem revision too high while trying to open /dev/md0.
> Couldn't find valid filesystem superblock.). Also fdisk /dev/sde shows
> no partition.
> My next step would be creating Linux RAID type partitions on the 6
> devices with fdisk and call mdadm --create with /dev/sde1 /dev/sdd1
> and so on.
> Is this step a possible solution for recovering the filesystem?
Depends.. Was the original array created on partitions, or on whole devices?
The saved '-E' output should show that.
Maybe you have the devices in the wrong order. The order you have looks odd
for a recently created array.
NeilBrown
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next prev parent reply other threads:[~2012-07-08 22:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-08 21:47 RAID5 superblock and filesystem recovery after re-creation Alexander Schleifer
2012-07-08 22:13 ` NeilBrown [this message]
2012-07-08 22:45 ` Alexander Schleifer
2012-07-09 0:02 ` NeilBrown
2012-07-09 6:50 ` Alexander Schleifer
2012-07-09 7:08 ` NeilBrown
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