Re: Help with data recovering

[Martin Steigerwald <Martin@lichtvoll.de>]

Am Montag, 4. Juni 2012 schrieb Hugo Mills:
> On Mon, Jun 04, 2012 at 12:24:05PM -0400, Maxim Mikheev wrote:
> > I run through all potential tree roots. It gave me everytime
> > messages like these:
> > 
> > parent transid verify failed on 3405159735296 wanted 9096 found 5263
> > parent transid verify failed on 3405159735296 wanted 9096 found 5263
[…] 
> > The largest recovered data is 12Kb.
> > max@s0:~/btrfs-recovering./recovered$ ls -lahs 3728819929088
> > total 28K
> > 4.0K drwxr-xr-x   3 root root 4.0K Jun  4 12:06 .
[…]
> > What can I do next?
> 
>    I'm out of ideas.
> 
>    At this point, though, you're probably looking at somebody writing
> custom code to scan the FS and attempt to find and retrieve anything
> that's recoverable.
> 
>    You might try writing a tool to scan all the disks for useful
> fragments of old trees, and see if you can find some of the tree roots
> independently of the tree of tree roots (which clearly isn't
> particularly functional right now). You might try simply scanning the
> disks looking for your lost data, and try to reconstruct as much of it
> as you can from that. You could try to find a company specialising in
> data recovery and pay them to try to get your data back. Or you might
> just have to accept that the data's gone and work on reconstructing
> it.

Only thing that comes to my mind thats still tryable without involving a 
data recover firm or engage a developer for an improved recovery tool is:

PhotoRec from testdisk package or some other data recovery tool that looks 
for headers for known fileformats like I think foremost.

It has some drawbacks:

- AFAIK it has no means to glue back together fragmented files, so these 
are likely gone or truncated

- filenames are lost

- directory structure is lost

I think it has been said, but I think its important to repeat it:

BTRFS - or any other filesystem - with RAID 0 without backup is not for 
important production data. Not ever. Maxim, I suggest if you learn 
anything out of this let it be at least this.

When I think about your setup, Maxim, the sentence "I want to have my data 
destroyed" comes to my mind.

I would try with photorec from testdisk first. Its quite easy to use.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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