Re: xfs_repair

[Frank Hellmann <frank@xxxxxxxxxxxxx>]

Hi Lukas!

If you have a chance, do a copy (via dd) to an empty disk before trying 
to recover anything and use that copied disk for playing around.

Rebuilds tend to start at the beginning of the disks and go sequentially 
further on. So my first guess is that the partition table is corrupt and 
will give xfs_repair strange partition layouts back. If you have any 
idea how it was laid out, I would suggest to restore it to the original 
layout, via fdisk or the like.

After that try an xfs_repair and now it should be able to find a 
suitable superblock. For the data I would fear that there will be a 
_lot_ of corrupted/missing files now.

As they say: RAID is _not_ a backup...

Anyway, good luck for the recovery.

                Cheers,
                        Frank...


Lukas Hejtmanek wrote:
> On Thu, Jan 06, 2005 at 11:58:16PM +0100, Mathieu Betrancourt wrote:
>
> > if that drive was part of a raid5 array its fail may cause zero data
> > loss because the 2 other drives have enough information to reconstruct
> > all data (see raid 5 design).
>
>
> ah. I did not explain it clearly.
>
> We have a server with two 200GB disks. We have an RAID5 array that was degraded.
> We want to fix RAID array using one of those 200GB disks. Unfortunately we took
> the bad one that was full of important data. Hope it is clear now.

--
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Frank Hellmann          Optical Art GmbH           Waterloohain 7a
DI Supervisor           http://www.opticalart.de   22769 Hamburg
frank@xxxxxxxxxxxxx     Tel: ++49 40 5111051       Fax: ++49 40 43169199