Request Help re: Damaged Partition

English Install/Boot/Login
1

Made a careless error. Had a windows partition sda2 on a dual boot system. From linux (sdb) I did a mount /dev/sda2 /mnt and then cp myfile /dev/sda2 rather than cp myfile /mnt. The partition appears unreadable. Does anyone know what happened and if my ntfs data is recoverable?

I’m just not sure how to recover or gain access to the file system. Can you recommend any utilities? Running openSuSE 12.3. I believe the transferred data was about 100kB. Thank you for your feedback. See below:

linux-e9ss:/home/mark # sfdisk /dev/sda
Checking that no-one is using this disk right now …
OK

Disk /dev/sda: 30394 cylinders, 255 heads, 63 sectors/track
Old situation:
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

Device Boot Start End #cyls #blocks Id System
/dev/sda1 0+ 7 8- 64228+ de Dell Utility
/dev/sda2 * 8 30392 30385 244067512+ 7 HPFS/NTFS/exFAT
/dev/sda3 0 - 0 0 0 Empty
/dev/sda4 0 - 0 0 0 Empty

linux-e9ss:/home/mark/ # mount /dev/sda2 /mnt
mount: unknown filesystem type ‘(null)’

linux-e9ss:/home/mark # mount -t ntfs /dev/sda2 /mnt
NTFS signature is missing.
Failed to mount ‘/dev/sda2’: Invalid argument
The device ‘/dev/sda2’ doesn’t seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

2

IMO

  1. Do not mount this disk in a Windows OS for now. Very important. If you do so, a signature might be written and other changes might be made on this disk.

  2. If you <really> value the data, image your disk. If you don’t already know, imaging is a special type of backup which copies the bits and bytes mechanically without any kind of understanding what the bits and bytes mean. This is different than a file-based backup which will check for file integrity and copy <only> what it thinks is valid.

  3. Working off a copy (preferred) or only after you’re certain your image backup is good, try inspecting the partitions non-intrusively. Use something like gparted live which will inspect your partition and format integrity. But don’t actually do anything until you hopefully have a better idea what has happened.

It’s a guess, but your NTFS data may have been corrupted. Once you understand how and what you can start to consider repair or recovery options.

BTW - If you really can make an exact disk copy to another disk, you <can> try mounting the copy on a Windows system and try running chkdsk.

IMO,
TSU

3

On 2013-11-17 00:16, mjjw wrote:
>
> Made a careless error. Had a windows partition sda2 on a dual boot
> system. From linux (sdb) I did a mount /dev/sda2 /mnt and then cp
> myfile /dev/sda2 rather than cp myfile /mnt. The partition appears
> unreadable. Does anyone know what happened and if my ntfs data is
> recoverable?

You wrote a file directly on the raw sda2 partition, not as a file. You
were working as root, obviously, a plain user does not have permission
to write there.

> I’m just not sure how to recover or gain access to the file system.
> Can you recommend any utilities? Running openSuSE 12.3. I believe the
> transferred data was about 100kB. Thank you for your feedback. See
> below:

100K? Well, as it only overwrote the start of the partition, all the
data will be there…

First step: image the entire partition, a byte by byte copy with dd, to
another disk with free space bigger than the entire sda2 partition.

Then, from Linux, I know two tools:

photorec

It will try to find files (it is efficient for multimedia files, photos,
mediocre or plain bad for other files) and copy them somewhere else. It
takes long.

testdisk.

It comes on the same package. It can recover some disasters. If it fails
on ntfs, the testdisk people recommend some proprietary software. I have
personally tried “Restorer Ultimate”.
http://www.restorer-ultimate.com/. It works on Windows, you
can download and test it. If you like what it finds and promises to
recover (it may take a day to get there), then you pay for it, get the
registration key, punch it, and the program continues.

I’m in no way related to that business; I simply used it on a friend
disk after we tried with photorec, which failed. We paid 30$ and it
worked. I can not vouch it works for you, but you can try it gratis…

In our case, the software did not repair the disk; instead it copied all
the files to another disk, and it did a much better job of it than
photorec. It properly found directory names. It only works on ntfs, I think.

–
Cheers / Saludos,

Carlos E. R.
(from 12.3 x86_64 “Dartmouth” at Telcontar)

4

I would like thank TSU and Carlos for taking the time to provide their very helpful responses. I am working with testdisk which appears to be a very nice utility. It is taking a while because of my busy schedule (and trying to be more careful).

5

On 2013-11-19 02:56, mjjw wrote:
>
> I would like thank TSU and Carlos for taking the time to provide their
> very helpful responses. I am working with testdisk which appears to be
> a very nice utility. It is taking a while because of my busy schedule
> (and trying to be more careful).

Oh, absolutely! Take your time and be careful, that’s very important.
Specially if you are not used to these tasks.

–
Cheers / Saludos,

Carlos E. R.
(from 12.3 x86_64 “Dartmouth” at Telcontar)

6

I was able to use testdisk to recover several thousand files by copying them to my linux disk drive. Testdisk is a very nice utility (it took a bit of patience to learn it); I earlier tried a number of other utilities w/o any success. I did have a backup but it was several months old and recreating all the deltas would have been very difficult. I will send them a donation. Thanks to the group here for some very good care.

7

On 2013-11-23 04:16, mjjw wrote:
>
> I was able to use testdisk to recover several thousand files by copying
> them to my linux disk drive. Testdisk is a very nice utility (it took
> a bit of patience to learn it); I earlier tried a number of other
> utilities w/o any success. I did have a backup but it was several
> months old and recreating all the deltas would have been very difficult.
> I will send them a donation. Thanks to the group here for some very
> good care.

Sounds good :slight_smile:

–
Cheers / Saludos,

Carlos E. R.
(from 12.3 x86_64 “Dartmouth” at Telcontar)