cgsecurity.org

Hello,

I hope someone can help me out here.

My data partition seems to have been reformatted during a Debian installation from ext3 to ext4. All the data is gone.

Running TestDisk's deeper scan, two partitions show up with identical characteristics http://i.imgur.com/DFRdDfY.png as seen in that screenshot. Unfortunately, once the scan completes, only one partition (plus the swap partition) is shown, and it contains no files.

Am I misunderstanding what is going on here? I have the Debian installation log that shows the formatting, so I am pretty confident that this is what happened. Is TestDisk dismissing the second (old) partition because they are both "linux" filesystems, and it assumes it is a fluke?

The partition is found once by its main superblock and again using one of the backup superblock.
As your partition has been reformated, it's useless to search for the partition, the partition hasn't been removed from the partition table, the partition isn't lost, your data are.
Use PhotoRec instead http://www.cgsecurity.org/wiki/PhotoRec_Step_By_Step