On 2018-04-23 22:08, Greg Freemyer wrote:
On Mon, Apr 2, 2018 at 9:44 AM, Turritopsis Dohrnii Teo En Ming
...
I know it's been 3 weeks, but I just noticed this thread.
I think the OP was written as a a joke :-)
Degaussing means degaussing.
https://en.wikipedia.org/wiki/Degaussing «Degaussing is the process of decreasing or eliminating a remnant magnetic field. It is named after the gauss, a unit of magnetism, which in turn was named after Carl Friedrich Gauss. Due to magnetic hysteresis, it is generally not possible to reduce a magnetic field completely to zero, so degaussing typically induces a very small "known" field referred to as bias. Degaussing was originally applied to reduce ships' magnetic signatures during World War II. Degaussing is also used to reduce magnetic fields in cathode ray tube monitors and to destroy data held on magnetic storage.» Notice that for data destruction purposes, we can just as well magnetize it all with a constant field, instead of trying to remove the existing magnetism, which is what is meant with degaussing.
Cheap way: You can buy a degaussing wand made for hard drives for $500 or so (from Amazon). Then you have to disassemble the drive and remove each platter (not all that hard).
Then pass the degaussing wand across every platter surface. It has to get very, very close to the surface. Maybe a couple sheets of paper could separate the platter from the wand.
I've tested this. The data is gone at that point, and the drive is totally unusable. Just throw it away. This meets NSA data destruction requirements. if you buy a NSA approved degaussing wand.
Can't it be low level formatted again?
If you simply pull the cover off the drive and pass the wand over the platter from about 5mm. Testing that, all of the data survived.
Expensive way: They sell degaussing machines the size of a refrigerator that work without disassembling the drive.
Greg
-- Cheers / Saludos, Carlos E. R. (from 42.3 x86_64 "Malachite" at Telcontar)