[Gllug] RAID superblock on /dev/sda2 appearing on /dev/sda

[John Edwards]

On Thu, Oct 14, 2010 at 06:23:44PM +0100, John Edwards wrote:
<snip> 
> Reading the mdadm RAID superblock docs:
> 	https://raid.wiki.kernel.org/index.php/RAID_superblock_formats
> 
> It appears that the current 0.90 superblocks are written towards
> the end of the device. Could it be possible that the end of the
> partition of very close to the end of the disk and so the two
> are getting confused?

This looks to be the case.

I've wiped the disks and then reinstalled with the partitions a few
MB smaller than the end of the disk and the problem is not present.

There is a similar problem decribed in an obscure Debian mdadm FAQ:
  http://git.debian.org/?p=pkg-mdadm/mdadm.git;a=blob_plain;f=debian/FAQ;hb=HEAD
though I did not see that particular error message.

There are a couple of alternative fixes being to use 1.x superblocks,
which can be positioned at different locations on the device, or
specify the devices names in the mdadm.conf file.


-- 
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|    John Edwards   Email: john at cornerstonelinux.co.uk    |
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