[RndTbl] Desperate plea for help

Trevor Cordes trevor at tecnopolis.ca
Mon Jun 7 08:34:25 CDT 2010


On 2010-06-04 Kevin McGregor wrote:
> I've got a HP ProLiant server running OpenFiler, and due to errors on
> my part, the SCSI drives got rearranged. Now the HP 6400 RAID
> controller complains that an "unsupported drive rearrangement has
> been attempted", and the logical volume is missing. Is there any way
> to recover the correct order of drives in the drive bay?

Very very strange that the physical ordering is important!  If Adam
hasn't already helped :-) ... here's my 2c:

How many drives are we talking?  If it's not large, there should be
only so many permutations and if you try every single one, one should
just magically work.

> Suggestions, aside from "use software RAID next time"?

If the data was super important, you could hook up the drives in a
non-raid environment and do so byte-level peeking to  try to figure out
the data arrangement (what raid level was it?), stripe sizes, etc.
That should be possible and from then a simple perl program could
extract all the data at the block level in the right order and dump to
another huge disk or array.  I think I could probably pull it off
unless the controller is doing something really wacky.  I've done
similar things in the past during raid disasters of my own (years ago
when I learned (the hard way) the value of RAID6 over RAID5).


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