Re: "Unformat" a ReiserFS partition : a testimony :-)

[Yury Umanets <umka@namesys.com>]

Nicolas Vanderavero wrote:

> Hello,

Hello Nicolas,

>
>
> while reinstalling a Debian on a new hard drive, I made the mistake to 
> format in reiserfs my good old /home which was on /dev/sda7 instead of 
> formatting the new /dev/hda7. Gasp ! Eight gigabytes lost ...
>
> Or ... maybe it was not totally lost :-) I immediately made a dump of 
> the partition with 'dd' and started grepping some known text on it. It 
> seemed that no data was really lost. I didn't know what to do. So I 
> read the man pages and found the reiserfsck command quite interesting :-)


You have lost the super block and probably old root node. I said 
"probably" because it might be not used in teh time you did format.

>
>
> Ok, I am a total newbie to filesystems and to ReiserFS. So maybe it 
> will sound trivial to you, but just in case it happens to anyone else, 
> I just wanted to say that running a reiserfsck --rebuild-tree -S on my 
> partition was enough to unformat it. I ended up with some file in 
> lost+found, but a 'file *' is enough to discover what they are. 

The first thing you should do in cases like this is to make backup. I 
hope you'll find eight gigabytes for that. Now you may feel free to do 
anything with you old partition. Then you should to do --rebuild-sb and 
try to fsck the partition with --check key. Then follow to fsck sugestions.

These should be enought for getting you partition back.

>
>
> So, maybe it would be usefull to add an entry in the "Example of 
> using" section of the man page of reiserfsck, saying something like : 
> "If you reformatted by mistake a reiserFS partition, you can try to 
> unformat it by running reiserfsck --rebuild-tree -S on it". 

Sounds good. Probably Vitaly should consider about that for including it 
in the next fsck -pre.

>
>
> Anyway, thank you for developing this filesystem.
> Nicolas Vanderavero.
>
>
>
>
>
>

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-- 
Yury Umanets