Ok, so a pretty big disk ~1-2TB (90% full, multiple partitions + 2 operating systems on it), needs to be encrypted and zeroed-out, and it's a bit too much data for backing it all up before encryption.

How do you recommend this to be done? Which tool should one use? How reliable would zeroing-out and encryption on-the-fly be anyway (don't want to loose any data in the process)?

5 Answers 5


I've used TrueCrypt http://www.truecrypt.org/ for whole disk encryption in the past for Windows and Linux.

Bruce Schneier has written articles about getting past whole disk encryption including these two:

  • I've used Truecrypt and haven't had any issues at all with it. I will say that the setup is easier than PGP whole disk encryption. Dec 7, 2010 at 3:49

Don't do it!

it's a bit too much data for backing it all up before encryption.

This seems to indicate that you would only back up to protect against loss during encryption. Everyone is answering your question, but this the the elephant in the room.

If you care about this data you need to back it up!

Until you do that, don't even think about encrypting or doing anything (and RAID N, for all values of N, is not backup).

  1. Hard drives are physical devices that fail.
  2. Hard drives are physical devices that fail.
  3. Hard drives are physical devices that fail.

(let alone the thousands of other ways to lose irreplaceable data)


Not doing backups is crazy and scary given that your data is business/mission critical and not your movie collection. So whatever you do, backup your data. Consider the following scenario: you're performing the encryption and during the encryption process you have a power failure on the power grid. In that case you would will lose a lot, if not all your data.

So invest the time to backup - even if you have to backup over a 56k line, it's worth the time.

Regarding which tool to use, see the other answers.

  • guess it's time for a brand new HDD
    – tkit
    Nov 13, 2010 at 9:51

Trying it with no backups eh? Scary!

I would rely on the commercial version of PGP to do whole disk encryption (works for Windows, Mac OS X, and Linux):



Depends a lot on which OS you're using, for example Windows supports EFS (Encrypted File System), which is considered quite secure and relatively reliable.
Very simple to perform - simply mark a checkbox on the folder...

There are also full disk encryption options, such as Windows7 BitLocker.

Again, depends a lot on your platforms.

  • I generaly use linux as my base OS most of the time, but have windows7 in dual boot on one machine and winxp in dual boot on one other machine.
    – tkit
    Nov 12, 2010 at 10:07
  • Yes, but if you're dualbooting the Linux OS won't be able to read the encryption keys, regardless.
    – AviD
    Nov 12, 2010 at 10:38

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