Dedoimedo posted a tutorial explaining how to recover lost partitions and data in Linux using tools like TestDisk, PhotoRec, recoverjpeg, plus manual recovery using hex editor, and more.

Losing important personal data is one of the biggest pains a user can experience in the digital world. No matter how hard we try, accidentals and hardware failures can happen and will inevitably happen. It's the matter of statistics, and just like casinos, the house always wins. In this case, data loss is the house.

To prevent tragedies, you must, I repeat, you must have multiple data backups, proven, consistent, restorable, verified now and then. But what if you don't? Most of computers users never bother with backups, and they only realize the enormity of their ways when it's too late. All right. So if you're down to tears and despair, there are a few things you can try before declaring Chapter 13 over your personal and emotional assets. This tutorial will try to teach you how to recover partitions and data stored on hard disks, as well as how to fix damaged pictures. Follow me.

  How to recover partitions and data using Linux