Have you ever erased important data?. This could be the solution

1 install in linux ubuntu

# apt-get install testdisk

2 Recovery

For example if the data erased is in the hda8 partition make a folder in another partition. See linux devices for details

# photorec /dev/hda8 /root/recuperado

- Select the partition type (ext2/ext3)

- Then SEARCH, this may take a while depends of the partition size .

3 Order 

# find /root/recuperado/ -name "*.txt" | xargs -i mv {} /root/ordenado/TEXT

# find /root/recuperado/ -name "*.jpg" | xargs -i mv {} /root/ordenado/IMG

and so the extension you want