How to wipe a HD?

[Aleksandar Milivojevic]

Thomas Cameron wrote:

> If you want to securely wipe the drive you can do a couple of things.  
> Have a look here for some commercial solutions.  Or you can just boot 
> off of the first FC CD in  rescue mode and run the command:
> 
> dd if=/dev/zero of=/dev/hda
> 
> Once the dd command hits the end of your disk it will end.  If you want 
> to *really* scrub your drive, many security experts recommend doing this 
> seven times.

What "many security experts" recommend is overwritting the disk seven 
times using different specially designed patterns for this purpuse. 
Overwriting it seven times with zeros using dd isn't going to do it.

An interesting thing to note is that government agencies are not allowed 
to use this technique to destroy the most sensitive data.  This may 
indicate NSA might have a way of recovering the data that was erased 
that way.  The actuall procedure they use to delete data from the disks 
is not publically available (my guess is that it includes physical 
destruction of media).

-- 
Aleksandar Milivojevic <amilivojevic at pbl.ca>    Pollard Banknote Limited
Systems Administrator                           1499 Buffalo Place
Tel: (204) 474-2323 ext 276                     Winnipeg, MB  R3T 1L7