Hi Jason,
On Wed, Jan 26, 2005 at 04:36:51PM -0600, Jason Hlady wrote:
> Hi there,
>
> I'm not even sure if this is the right mailing list for my problem, but
> I was hoping that someone here could at least point me to the correct
> set of people who might help me get the data back off the tapes.
You've asked at the right place.
> I
> have graduate students facing the loss of months and years of work, and
> I would appreciate any help that could be ferried my way.
>
> I have had a catastrophic RAID failure on a 700GB XFS filesystem (OS =
> Mandrake 9.1 on IBM x340) and am looking to try and restore from tape.
> I have had backups running on my Ultrium LTO tape drive. All of the
> dumps that we have done in the past two years seem to have this same
> restoring problem. We hadn't checked whether we could restore from the
> tapes recently, since we had successfully managed to dump and resture
> using xfsdump and xfsrestore years earlier :( .
>
> I apologize in advance for the length/verbosity of this email. I just
> wanted to provide some information in advance.
>
I understand your concern with such large data.
But as it says on the back of The Hitch Hikers Guide to the Galaxy,
DON'T PANIC :-) And don't destroy those tapes ;-)
Looking thru your email, it really looks like a block size problem on
reading of the tapes. I have seen similar problems in the past.
My first suggestion is to use the same strategy and blocksize in the
restore as you did in the dump. That is use "-m -b 245760".
You said you tried "-b 245760" but you should also use the same
strategy "-m".
The minrmt strategy doesn't rely on all the status info from the drive.
From memory, the "-b" option shouldn't be ignored as you suspected.
If this doesn't work don't despair.
In the worst case, I can find an old program which I have somewhere,
which hunts for headers and extracts data which I used a while ago
on a blocksize problem on an IRIX dump (have no idea how that IRIX one
happened - od(1)'ing on that dump it was in a strange format).
I also have something which looks at the headers to confirm the
blocksize that was used. It has been a while...
(We know the dump format, so if the data is there, we should be able
to extract it ;-)
BTW, how come your dumps are always interrupted?
--Tim
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