Message-ID: <3C3BC38C.7010808@fit.edu>
Date: Tue, 08 Jan 2002 23:14:04 -0500
From: Kervin Pierre <kpierre@fit.edu>
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To: Richard Gooch <rgooch@ras.ucalgary.ca>
CC: Andreas Dilger <adilger@turbolabs.com>, linux-kernel@vger.kernel.org
Subject: Re: fs corruption recovery?
In-Reply-To: <3C3BB082.8020204@fit.edu>	<20020108200705.S769@lynx.adilger.int> <200201090326.g093QBF27608@vindaloo.ras.ucalgary.ca>
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Hi,

Thanks for the input.  

Do you still have any of those scripts around? Or can you give me a 
general idea of how you used debugfs to retrieve your files?

I was actually expecting to spend a few hundred instead of a few thousand.

Thanks,
-Kervin

Richard Gooch wrote:

>Andreas Dilger writes:
>
>>On Jan 08, 2002  21:52 -0500, Kervin Pierre wrote:
>>
>>>I install and used 2.4.17 for about a week before my filesystem 
>>>corrupted.  I've tried 'fsck -a' but it complains that there was no 
>>>valid superblock found.
>>>
>>Try "e2fsck -B 4096 -b 32768 <device>" instead.
>>
>>>Are there any tools or techniques that will recover data from the 
>>>corrupted filesystem even if there isn't a valid superblock?  Or is 
>>>there a way to write a temporary superblock so I can access the 
>>>information on the disk?
>>>
>>The ext2 format (includes ext3) has backup superblocks for just this reason.
>>
>>>Lastly, if all else fails I'm going to try sending the drive one of 
>>>those 'file recovery companies'.  Does anyone have a recommendation for 
>>>a particular company?  I'm guessing that there'll be a few that wouldn't 
>>>know what to do with a ext3 partition.
>>>
>>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...
>
>				Regards,
>
>					Richard....
>Permanent: rgooch@atnf.csiro.au
>Current:   rgooch@ras.ucalgary.ca
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