[CentOS] Question about dd (fill a hard disks' unused space with blanks)

Kevin Krieser a écrit :

> 
> I've done the zeroing out thing on mounted filesystems before when I  
> wanted to move the contents of a drive to another.  zeroing out before  
> would be best if you planned to do an install, then back it up for  
> later.  Otherwise, you end up with a lot of unused space that has  
> remnants of old data scattered around.

Yeah, but I'm a bit confused here. How would you go about it from a LiveCD ?