We all know that when you simply delete a file it's possible to recover it later. Sometimes this is useful, if you accidentally delete something important; but most of the time this is a problem, and you really want that file gone forever. This howto will explain how to delete a file in linux securely and permanently, so it can never be recovered.

I recently read a doctorate’s thesis on file system robustness by Vijayan Prabhakaran from the University of Wisconsin. It’s very interesting, and may explain in part the recent ruckus on the LKML around file systems.