"Cannot find file system superblock" error - how to recover?

[Sergey 'DoubleF' Zaharchenko]

On Tue, 6 Jan 2004 09:48:40 -0800 (PST)
"Scott I. Remick" <scott at sremick.net> probably wrote:

> 
> --- Sergey 'DoubleF' Zaharchenko <doublef at tele-kom.ru> wrote:
> 
> > I can't find a zero-bad floppy in this place! It's all the holidays!
> 
> That's what AOL disks (vs. discs) used to be good for. :)
> 
> > With `c', they're all offset by 63(why?). But still, you can mount the
> > partitions on the ad4s1, so the disklabel should be ok...
> 
> Yeah. Starts to suggest what we were thinking was a evidence related to the
> problem is really unrelated and "normal" behavior (is disklabel/bsdlabel
> only meant to be run on slices and not bsd-partitions?). Are we looking in
> the wrong place?

After trying out 5.2-RC2, it seems like the offsets reported with the
`c' slice are from the beginning of the disk, not from the beginning of
the slice. That accounts for the +63 difference. I guess it's documented
somewhere, but as I don't use 5.x I haven't read its docs.

> What about that potentially good superblock we found a
> while ago? (the skip 16 one that contained "/data" in it) Should we be
> saving that somewhere while we can? (how?)

I think you already have a copy (the data at offset 32 seems to be it).
If you want, do a

# dd if=/dev/ad6s1 skip=16 count=16 of=/some/file

Please tell me everything what you tried to use to mount/fsck the drive
(and the results, of course).

> Anyone out there know 5.x file-system dirtiness like the back of their hand?
> C'mon, you know you wanna join the fun. :)

Try booting from a 4.x floppy and doing it all over again... The FS is
UFS1, isn't it?

-- 
DoubleF
Why does New Jersey have more toxic waste dumps and California have
more lawyers?

New Jersey had first choice.
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