[ale] destroy old drives

[Alex Carver]

If someone really wants your data, holes don't matter.  The rest of the
platter is still intact in that case and can have the data extracted.

There's also no guarantee that Dban can write enough to be sure that the
magnetic domains are fully randomized deep in the platter.  The longer
data sits statically on the disk  the more opportunity for the surface
domain to imprint on deeper domains (this is actually a problem with
magnetic tape, magnetic data can print through from one layer of tape to
the next layer when it's wound on the spindle).

A serious entity can perform a deep level scan of the platter and
retrieve the low level signal under the surface domains and see previous
data.  The drive head typically isn't powerful enough to write that
deeply because it has to keep the tracks narrow.

On 2019-04-11 12:13, Steve Litt via Ale wrote:
> On Wed, 10 Apr 2019 22:11:42 -0400
> Jim Kinney <jim.kinney at gmail.com> wrote:
> 
>> Dban advantage: it can be done across hundreds or thousands of drives
>> before larcenous third party "shredders" physically touch the drives.
> 
> That's a good point.
> 
> Doesn't dban take an hour or more? How many drives can I do with one
> computer? How long would it take to test whether each is really blank?
> 
> What might be nice with 1000 drives to do is dban followed by drilling
> 3 holes in each drive. I'd say each drive would take 1 minute for 3
> holes, so it's about 2 days for one employee to drill the holes. Or,
> perhaps, one employee could both dban and drill the holes, drilling the
> holes while the next batch is dbanning.