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From: "Christoph P. Kukulies" <kuku@gilberto.physik.RWTH-Aachen.DE>
Message-Id: <199509121823.UAA00814@gilberto.physik.RWTH-Aachen.DE>
Subject: Re: recovering a FS
To: terry@lambert.org (Terry Lambert)
Date: Tue, 12 Sep 1995 20:23:12 +0200 (MET DST)
Cc: kuku@gilberto.physik.RWTH-Aachen.DE,
        freebsd-questions@freefall.freebsd.org
In-Reply-To: <199509121725.KAA21886@phaeton.artisoft.com> from "Terry Lambert" at Sep 12, 95 10:25:27 am
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[...]
> > Is there a way (with a program or whatever tool) to reestablish
> > or recover a disklabel from a given disk?
> > 
> > Presently the only chance to find certain things is to grep through
> > the raw device :-(
> 
> Binary grep the raw device for the file system magic number; this will
> give the location of the superblock structures.
> 
> Look at fsck for the definition of the "dynamic" fields in the superblock.
> These will be non-zero on the first one.
> 
> This will give you the disk offset of the superblocks, which you can then
> enter into your disklabel.

Thanks. Magically the disklabel worked when I mounted the partition in 
question but fsck'ing told me that the Superblock was corrupt and whether
it should look for alternate superblock. I bailed out of fsck
and hand made a custom 1.1.5.1 floppy that allowed me to 
nfs mount my backup machine and tar the files over the net.

I'm sane again :-)

> 
> 
> I have often though the perhaps swap should be first to ensure that
> an overwrite like this would not necessarily touch important data.
> 
> On the other hand, you aren't supposed to put anything important in
> the '/' but distribution files (and system configuration because of
> stupid writeable '/etc'), and '/' has to be below 1024 for BIOS to
> see it.
> 
> 
> 					Terry Lambert
> 					terry@lambert.org
> ---
> Any opinions in this posting are my own and not those of my present
> or previous employers.
> 

--Chris Christoph P. Kukulies kuku@gil.physik.rwth-aachen.de