Re: Is there a tool to examine raw metadata?

On Wed, 20 Nov 2013 13:26:10 -0500 Veedar Hokstadt [off-list ref] wrote:

Greetings,
Consider a 3 drive RAID5 where each drive has lost it's partitioning
info. Running mdadm -E does not find a superblock. But using hexedit
an mdadm superblock can be found in tact near the end of each drive.

Is there perhaps a tool I can point at the superblock to decode it? Or
trick mdadm into reporting the contents of the superblock?

I know I can look at the superblock format doc and translate it by
hand but I was hoping for an easier way.   Thanks for any help.  -V
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

If you use losetup to create a device pointing to the original but with an
offset to match where you think the partition was, then run "mdadm -E" on the
loop device.

You could probably do:

 for i in {1..1000}
 do
  losetup -o $i /dev/loop0 /dev/whatever
  echo $i
  mdadm -E /dev/loop0
  mdadm -d /dev/loop0
 done

NeilBrown