[Bulk] Re:Writing over a drive using /dev/zero

[Yanni Chiu]

On 30/11/10 11:42 AM, William Muriithi wrote:
>
> This is something I am very doubtful about.  In fact, I am reasonably
> as in 80 % sure it impossible to extract data from a drive that has
> been overwritten with zeros using dd.  You do not have to fill it,
> lets say overwrite 60% of the drive.

Back when 1.2M floppies were common, the recording surface used for each 
bit of data was huge. Also, the write head alignment was not very tight. 
The result was that if you "looked" around the recording surface (i.e. 
off the track), you could recover what was there, before the zeros were 
written. That's the explanation I remember. Of course, with today's 
densities, the chance of finding the old data is much slimmer than before.

-- 
Yanni
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists