[UFO Chicago] recommendations for completely erasing a hard drive?

[Jordan Bettis]

On Mon, May 28, 2007 at 07:36:21PM -0700, Jesse Becker wrote:
> 
> --- Brian Sobolak <brian at planetshwoop.com> wrote:
> 
> > Charles Marshall wrote:
> > > Brian,
> > > Boot into a Knoppix cd, then:
> > > 
> > >     cat /dev/zero > /dev/[s|h]d[a|b|c|d]
> > > 
> > > Haven't done it in a while, but I think that worked
> > when I had to do it.
> > 
> > Hmm.  That would certainly work, but I seem to recall a
> > tool that did 5 
> > passes (all 1s, then all 0s, etc.) to make sure it was
> > erased.  Does 
> > that ring a bell?
> 
> The incantation above is a bad idea.  Yes, it will nuke the
> data, but a large portion of that data is probably
> retrievable.  At least use random data, and dd is faster
> than cat:
> 
>   dd if=/dev/random bs=4k of=/dev/[sh]d[a-f]

You can do this very easily from any recovery CD, for instance:

http://www.sysresccd.org/

Which I find to be a great program.

BTW: To make it not take ten centuries to write several gigabytes,
I'd recommend using /dev/urandom rather than /dev/random.

-- 
Jordan Bettis -- Chicago Il.
  <http://neighborhoods.chicago.il.us>                  
    Photographs of Life in the Neighborhoods of Chicago