I used GParted to convert a primary partition to extended one after copying the data to another partition. After having the extended partition I moved the data back. To my utter shock after a restart I found out that the new extended partition did convert into "unallocated space". I tried installing testdisk. Testdisk could identify the partition as a primary partition and not the newly created extended partition. So what should I do now? I badly want the data back.
Ubuntu – Unallocated space with important data
data-recoverygpartedtestdisk
Best Answer
It's rather difficult to solve such problems via the internet, and it certainly doesn't fit the question -> answer nature of askubuntu.com.
Anyways:
Whenever such things happen, immediately shutdown the system and don't write (or install) anything to it!
Start a live CD, download the 6.12-WIP version of TestDisk (you just need to unpack it, then start it with
sudo ./testdisk), let it search for partitions, examine the contents of the found partitions, and if you are 100% sure that you've found the right partition, restore it.You can find a couple of detailed examples in the TestDisk wiki (e.g., TestDisk step-by-step).
If you don't feel comfortable doing it yourself, ask someone that has experience with this tool to do it for you. Any mistake can lead to permanent loss of data!