Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

I heard about people that used tools to recover deleted data and found a lot of unusual data, that after discovered that the their brand new pc in truth was used...

When discarding HD's, as sysadmin, we need be sure that the data in disk is unrecoverable.

Do you know some tool to safely format the hd then the data cannot be restored? As usual, free is better.

share|improve this question
You question title is not very specific –  Eddie May 4 '09 at 15:53
Duplicate of several threads already on here. –  Brian Knoblauch May 6 '09 at 19:27

7 Answers 7

up vote 4 down vote accepted


Darik's Boot and Nuke ("DBAN") is a self-contained boot disk that securely wipes the hard disks of most computers. DBAN will automatically and completely delete the contents of any hard disk that it can detect, which makes it an appropriate utility for bulk or emergency data destruction.

It does a good enough job. Like jldugger said it's enough to write 0s to the drive, you could always smash it with a hammer and take out some frustration about "that one user" shrug

share|improve this answer

See: http://serverfault.com/questions/2067/sugestions-for-cleansing-pcs-before-recycling-disposal

share|improve this answer
Nice, but my question is a bit more specific. –  Click Ok May 4 '09 at 5:50
If you read some of the top answers (especially my one! :-P), you'll see that they adequately address your question too. :-) –  Chris Jester-Young May 4 '09 at 6:22
or see serverfault.com/questions/959/… –  Hamish Downer May 4 '09 at 10:46

Use the free Eraser software to securely remove sensitive data from your hard drive. You can even choose the data wiping algorithm and the strength of the erase making it almost impossible to recover your data.

share|improve this answer

You would do well to read the Epilogue to Gutemann's publication "Secure Deletion of Data from Magnetic and Solid-State Memory". The gist is that recovering data isn't possible on newer technology, so just write zeros to the drive and call it a day, or use Gutemann's tool to satisfy the tin-foil crowd.

share|improve this answer
  • MHDD ERASE commadd. MHDD is also good tool for remap, fix drive, etc.
  • shred /dev/[yourdevice]

    1. shred is a part of GNU coreutils (in Windows it can be used as a part of cygwin).
    2. Individual files can't be shredded totally securely on journaling filesystems, though.
    3. If you are shedding the device make sure to shred journal as well (journal can be stored on separate device).
share|improve this answer
most people that uses OS'es these days use journaled file systems, which the shred utility itself says it is of limited use for... –  Steen Oct 12 '10 at 21:40
Thanks. I've improved my answer. –  Alex Bolotov Oct 19 '10 at 22:52

As the others have said, writing zeroes should be sufficient. You can also write random data, or do a secure wipe, if you're really paranoid.

Someone wrote an open challenge to anyone who could recover data from a drive that was overwritten with zeroes, and also contacted 3 data recovery firms for the challenge: http://hostjury.com/blog/view/195/the-great-zero-challenge-remains-unaccepted

The article includes a paraphrased conversation with someone at one of the data recovery firms contacted for the challenge:

"According to our Unix team, there is less than a zero percent chance of data recovery after that dd command. The drive itself has been overwritten in a very fundamental manner. However, if for legal reasons you need to demonstrate that an effort is being made to recover some or all of the data, go ahead and send it in and we'll certainly make an effort, but again, from what you've told us, our engineers are certain that we cannot recover data from the drive. We'll email you a quote."

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.