Writing over a drive using /dev/zero

[Lennart Sorensen]

On Mon, Nov 29, 2010 at 08:53:20PM -0500, Walter Dnes wrote:
>   The only thing I have to add is that if you're trying to securely wipe
> a drive, you should use /dev/urandom instead of /dev/zero.  And if CSIS
> or CIA really want the data, they might still be able to retreive most
> of it.  If you really, really want to guarantee the data won't be
> retreived, you have to take out the platters and disolve them in a vat
> of acid.  If the data on the disk isn't *THAT* sensitive, 3 or 4 passes
> with /dev/urandom will usually do the trick.

I have also read from some security experts that the overwriting with
random data is a load of crap that they wish people would stop advising.

Who is right I don't know.  I don't think I have ever had any data that
I didn't consider sufficiently wiped by /dev/zero.

To some extent, I think there are easier ways to get at your data than
using electron microscopes and the like to find out what your data was
before you erased it.

-- 
Len Sorensen
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