Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have moved to Ubuntu 12 and chosen to use full disk encryption (encrypted LVM).

So now I'm wondering: should I shred (eg: with secure-delete package, srm) the free disk space to remove any remnant windows might have left?

Is free disk space treated any different?

share|improve this question

The standard recommendation, is that you over-write a disk/volume with random data before you setup luks. The Ubuntu installer will even offer to do this for you if you select the Expert mode. I don't believe the latest version will do this by default though, but I haven't actually tried it. This is often skipped/ignored because the process will take a long time.

But no, luks does not automatically fill or over-write blocks when it is setup.

Using the psuedo random generator in badblocks (badblocks -c 10240 -wsvt random /dev/<device>)is usually considered good enough and suggested as a good method to wipe a volume by most LUKS guides and HOWTOs.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.