How to recover files after changing partition filesystem?

Question

I tried to install Ubuntu 12.10 but for some reason the process stopped half-way and wouldn't progress, after some time waiting I decided to reboot and to my surprise my D: partition, where I have some files stored, was entirely occupied by Ubuntu.

I assume that the filesystem of the partition was changed from NFTS to ext4, so I lost access to the files on Windows. Later I recreated the D: partition again as NFTS, with its original size, and didn't do anything else with it, hoping that none of the files would be overwritten, but the partition was empty. I expected that, as I assume during the Ubuntu installation, the partition is formatted.

However I was hoping it would be possible to recover them. I already used PhotoRec tool to try the recovery of such files but all I am retrieving is thousands of text files, apart from a few intact files randomly named.

Is there any possibility to recover those files, given the circumstances described above?

Answer 1

If indeed the filesystem was damaged or destroyed you do not hold the best cards, since the filesystem is as you surely know the link to the files in the partitions.

Still of course there might be some change to recover the files by using tools which work upon the concept that most files are recocnized by the sequence of their very first bytes. This means that even when the filesystems is missing some files can be found by searching the content for the patterns of files. This all relies on the finding of so called magic bytes

A programme to do such a search could be the Ubuntu package magicrescue

Normaly you should have backup... so all the problem should not exists... since you would revocer your files from the backup. Just in case you do not have backup... Do not write anymore on the partition you expect to still contain some of your data. You might by this overwrite data valueable to you.

A good procedure would be to use dd to backup the partitions content first.

Some other tools you might wanna tryout are

• testdisk http://www.cgsecurity.org/wiki/TestDisk (which has some ability to repair less sophisticated Filesystems like vfat/Fat32 etc) and also to search for files on lost paritions
• System Rescue CD (A ios image of a live-linux which comes with some tools for data recovery for instance testdisk) http://www.sysresccd.org/SystemRescueCd_Homepage

good luck. PS have some more search in the Askubuntu.com. It might very well be that you have not yet found some information upon data rescue already available on the side already.

good luck

You mentioned that you :

[...] assume that the filesystem of the partition was changed from NFTS to ext4,[...]

with sudo fdisk /dev/sda -l you can find out what your partition layout looks like.