Recover Lost Superblocks?

[Polytropon]

Hi!

On Mon, 21 Jul 2008 11:57:09 +0200 (CEST), "John Morgan Salomon" <john at zog.net> wrote:
> Before you ask, this was the backup server.  My primary box had decided to
> die shortly before.  I had no backup backup server.  Murphy strikes.

I completely do understand you, I'm suffering from a similar problem
at the moment, but much worse than yours...

Buy tape drives! Buy tape drives! Buy tape drives! :-)


> Can someone recommend a way to manually scan the entire partition (either
> aacd0, aacd0s1 or aacd0s1c) for formerly present filesystems?  I am 99%
> sure that all the data is still present, and if I reinstall the
> superblocks I'll be able to boot the array, mount the filesystems and get
> the data off before I continue.  I don't know whether I've missed any
> gpart options (I have the impression it only scans for lost partitions,
> not ufs filesystem signatures.)

As far as I know - NB that I'm just starting to learn more about UFS,
shame on me that I'll do this just as every piece of data is gone -
there are more than one superblock present. According to "man fsck_ufs",
this could be a starting point:

     -b      Use the block specified immediately after the flag as the super
             block for the file system.  An alternate super block is usually
             located at block 32 for UFS1, and block 160 for UFS2.

This applies if just the first superblock is gone.

Before you start experimenting, maybe it's a good idea to dd the
data out of the disks and run fsck on the images? I'm not sure...


> Any help, tips or pointers would be tremendously appreciated.

Hope you're lucky.






-- 
Polytropon
>From Magdeburg, Germany
Happy FreeBSD user since 4.0