Re: fs corruption recovery?

[Helge Hafting <helgehaf@aitel.hist.no>]

Richard Gooch wrote:
> 
> Andreas Dilger writes:
[...]
> > Is the data really that valuable, and you don't have a backup?  It may
> > cost you several thousand dollars to do a recovery from such a company.
> > Yet, it isn't worth doing backups, it appears.
> 
> And these companies don't really do much that you can't do yourself. I
> had a failing drive some years ago, where some sectors couldn't be
> read. So I tried to dd the raw device to a file elsewhere. Of course,
> dd will quit when it has an I/O error. So I wrote a recovery utility
> that writes a zero sector if reading the input sector gives an I/O
> error. Unfortunately, I couldn't mount the file (too much corruption),
> but I was able to use debugfs on it. I got the most important data
> back.
> 
> While I was waiting for 48 hours for the data to be pulled off (each
> time a bad sector was encountered, the drive would retry several
> times, with lots of clicking and rattling), I contacted one of these
> recovery companies. I wanted to know if they could recover the bad
> sectors. I was told no. After some probing, it turns out that all they
> do is basically what I was doing. They just charge $2000 for it.
> 
> No doubt if you took your drive to your local CIA/KGB/MI6 offices,
> they could recover some of those bad sectors. But I hear they charge
> their customers quite a lot...

No need for CIA/KGB.  There are companies that do more than this.  
If necessary, they disassemble the drive in a clean room and use 
their own reading equipment.  This allows recovery
from fried drive electronics and broken motors/heads.  And sometimes
(partial) recovery from scratches and other bad sectors.

If you really need this, consider
http://www.ibasuk.com/technology/patan.htm

Helge Hafting