needs help, root inode gone after usb bus reset on sata disks

[Jelle de Jong]

Theodore Tso wrote:
> On Thu, May 29, 2008 at 10:15:08PM +0200, Jelle de Jong wrote:
>> I did the following:
>>
>> debugfs -w /dev/sda1
>> debugfs: features dir_index filetype sparse_super
>> debugfs: quit
>>
>> then i run
>>
>> e2fsck -nf /dev/sda1
>>
>> to see if it still wanted to relocate inodes. This was not the case 
>> anymore, however it still wanted to relocate the root inode...
>>
>> I then run:
>>
>> e2fsck -f /dev/sda1
>>
>> and manual answer yes to the question until i had to enter a lot of "y" 
>> (see logs) and killed the program with ctrl-c
> 
> what answers did you answer yes to?  I don't have a log of your
> "e2fsck -f /dev/sda1" run, and so I can't tell what happened.  The
> e2fsck -fy run you gave me was large, but information-free, since it
> just had pass #5 messages regarding adjusting accounting information.
> 
> If it was just deleting the root inode (because it was corrupted), and
> creating a new root inode, that doesn't explain why all of the inodes
> disappeared, unless the inode table had somehow gotten completely
> zero'ed out
> 
> At this point, what I would probably suggest is that you run 
> 
> 	e2image -r /dev/hda1 - | bzip2 > hda1.e2i.bz2
> 
> ... and put it someplace where I can download it and take a look at
> what the heck happened to your filesystem.
> 
> By the way, please look at the "script" command ("man script"); it is
> very handy for capturing a record of what an interactive session with
> a program like e2fsck.
> 

Thanks for all the info Ted,

http://www.powercraft.nl/temp/e2image-r-sda1-v0.1.1.e2i.bz2

I did some experimenting and to see if I can find some data on the disk 
by doing the below command on an unaltered backup:

e2fsck -fy /dev/sda1 > e2fsck-fy-info-sda1-v0.1.1j.txt 2>&1

However no files where found, so maybe something when wrong with the dd 
backup.

I don't now if there is a way to see if there is actual data on the disk.

So for now i am giving up on recovery the data, maybe you can get a glue 
of what the hack happened to the file system and learn something new...

The only thing i would like to now is how to backup and restore the 
filesystem. (for example i am going to setup a raid setup but this kind 
of file system crashes are not covered with a raid setup)

Thanks in advance,

Jelle