Date: Thu, 23 Feb 2006 07:45:15 -1000 From: Clifton Royston <cliftonr@lava.net> To: Dave <dmehler26@woh.rr.com> Cc: freebsd-hackers@freebsd.org Subject: Re: urgent, need to recover superblock! Message-ID: <20060223174515.GF1494@lava.net> In-Reply-To: <20060223120024.36B4F16A423@hub.freebsd.org> References: <20060223120024.36B4F16A423@hub.freebsd.org>
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On Thu, Feb 23, 2006 at 12:00:24PM +0000, freebsd-hackers-request@freebsd.org wrote:
> Date: Wed, 22 Feb 2006 22:23:13 -0500
> From: "Dave" <dmehler26@woh.rr.com>
> Subject: urgent, need to recover superblock!
> To: <freebsd-hackers@freebsd.org>
> Message-ID: <015701c63828$7af60a70$0200a8c0@satellite>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Hello,
> Some urgency on this issue! I've got a 10 gb ide drive that has
> critical data on one of it's
> partitions /dev/ad1e. This drive was originally gmirrored in
> another box it worked fine, it was the master drive. Now i've
> installed this drive as a slave in another 6.0 box, and now it
> shows up as ad1 with the partition i want being ad1e. I did a mount it
> worked fine. So i knew the drive was working, i then unmounted the
> partition, and tried to dump it to another drive. This didn't work, dump got
> an error about incorrect superblock. I then did a mount
> -o ro /dev/ad1e /mnt and i'm getting an error "Incorrect
> superblock" from mount. I then tried fsck /dev/ad1e and got the
> same error msg. These partitions were formatted with ufs2 as their
> filesystem. I then ran bsdlabel ad1 and got a printout of my label,
> this showed up which gives me hope that this data can be retrieved.
> An error i'm getting from bsdlabel says that the c: partition does not cover
> the
> entire disk and that may result in utilities not working correctly. Any
> help appreciated.
> Some urgency!
> Dave.
It sounds like you partitioned and formatted the drive as part of a
pair of drives under a gmirror originally, but then on the second
system mounted it as a raw drive?
If so, you should at once try remounting it *under gmirror* on the
second system. (See Handbook chapter 18.4 - do "gmirror load", then
"mount /dev/mirror/gm0s1e". ) I have only used gmirror on one system
(and love it!) but in my understanding it necessarily ends up slightly
changing the apparent physical layout of the drive when you do the
"gmirror label" and then load it. That bsdlabel error is suggestive
that that might be the problem.
I expect you should see bsdlabel report the right thing for
/dev/mirror/gm0 after you do this. It is possible that the "incorrect
superblock" filesystem error may simply vanish when you do this. It is
also possible (if this is the issue) that the filesystem got partially
trashed when you first mounted it r/w without gmirror.
In either case, try starting from there first. If that is where you
need to be, running the recovery tools while treating it as a raw drive
might damage it further as per the warning from bsdlabel.
-- Clifton
--
Clifton Royston -- cliftonr@iandicomputing.com / cliftonr@lava.net
President - I and I Computing * http://www.iandicomputing.com/
Custom programming, network design, systems and network consulting services
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