TestDisk

TestDisk is a free and open source, cross platform data recovery suite. TestDisk was written by Christophe Grenier in C and is capable of recovering files and partitions on FAT12, FAT16, FAT32, NTFS, and ext2 filesystems.

Emerge
Install TestDisk:

Usage
Start TestDisk:

TestDisk can work with raw disks created with :

PhotoRec
PhotoRec is a signature based recovery tool that is installed alongside TestDisk. PhotoRec scans partitions for file header information in order to find lost or deleted files. Since file header information is queried, PhotoRec can work on a variety of file systems and is capable of finding over 400 types of files. Files found by PhotoRec do not have their original file name; recovered data is grouped into folders and labeled with a file extension matching the header information (ASCII files are labeled, JPEG files named , PNG files named , etc.). In order to find the specific file, the content of each file must be searched.

Start PhotoRec:

External resources

 * A TestDisk step-by-step guide