Ubuntu system corrupted

[Petter Adsen]

On Wed, 27 May 2015 22:59:42 +0200
Nils Kassube <kassube at gmx.net> wrote:

> Hari wrote:
> >   I have a dual boot - Ubuntu and windows 7. I recently wass playing
> > around in the ubuntu and used the 'dd' command and it kinda
> > corrupted my linux file system. I exactly dont know what happened
> > to Linux now. All my data is missing. I did the boot-repair and now
> > the grub is removed and it is directly booting to windows. Please
> > help me recover all my data in ubuntu. It is very important. Please
> > help me with the process. I am desperate!!
> > 
> > Here is the pastebin link containing the logs.
> > 
> > paste.ubuntu.com/11395840/
> 
> | sda6:
> ...
> | Mounting failed:   mount: unknown filesystem type ''
> 
> To me it looks like your Ubuntu system was on /dev/sda6 (the other 
> partitions seem to be OK). With your dd command you overwrote vital 
> parts of that partition. IMHO it would be best to try to recover 
> remaining data using photorec / testdisk (unless you have a backup of 
> your valuable data). Then you would reinstall the system from
> scratch. But please wait for other opinions before you proceed.

I'm with Nils on this. photorec and/or testdisk may be able to retrieve
some of the data for you, you can also try gddrescue or myrescue.

The best approach, if you have the space, would be to make an image of
the broken file system, and run the rescue tools on the image, or at
least make sure you do not disturb the broken partition further while
attempting to rescue data. Thus, if one tool fails to rescue anything,
you can try the others, as no changes has been made to it.

This is also a really good candidate for an occasion to learn the value
of frequent backups. And to be careful when you run things as root.

To add to this, I feel sorry for you - I really do. We have all been in
a similar situation at one time, and the most valuable thing you can
get out of this (apart from retrieving your data) is to learn that
backups are necessary, not optional.

It is also important to state that when you work to retrieve your data,
it is far better to ask here first than to do something you don't
understand the consequences of. The process can get complex, and you
might need to make difficult choices. Get all the help you can.

There are also commercial tools for data recovery, the only one I know
of is R-Studio, but I know there are more. I haven't tried any of them,
though, so I don't know if they're worth the money. If the data is
absolutely critical, you should take it to a professional data recovery
service rather than do anything wrong and ruin them completely.

Good luck!

Petter

-- 
"I'm ionized"
"Are you sure?"
"I'm positive."
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