I ncreasingly, one of the most valuable commodities is information. But this isn’t just for big business – most of us have data that is valuable in one way or another. So, preserving that data is important, because the consequences of failing to do so can range from inconvenience to financial hardship. And as we’re all well aware, there can also be severe consequences if our data falls into the wrong hands. Here we address the two inter-related themes of data recovery following accidental deletion or hard disk failure, and secure deletion so that, when you do delete data, nobody else can recover it. Mostly we’re considering traditional magnetic hard disks, but we also look at the different challenges that apply to SSDs (see Solid-State Drives boxout below).
Check your bin!
Sometimes the obvious gets overlooked; that obvious measure is to restore the file from the Rubbish Bin (Trash if the language is set to American English), the special folder that stores files that have been deleted. Do bear it in mind. After all, magically restoring your friend’s files might just promote you to hero status. If you deleted a file using the rm (remove) command in the terminal, that file will have been genuinely deleted, as opposed to being dispatched to the Rubbish Bin, so the trivially simple method of recovering the file won’t work. If the file was deleted in the file manager – as will almost certainly be the case with your non-technically minded friend – there’s a good chance it’s residing in the Rubbish Bin. Certainly, that is what happens if you select a file and hit the Delete key, although Shift+ Delete bypasses the Rubbish Bin. It’s also possible, permissions depending, to delete a file or send it to the Rubbish Bin by selecting the appropriate option having right-clicked on a file.
So how do you
