[CentOS] help fdisk and dd

Thu Mar 4 19:48:03 UTC 2010
John R Pierce <pierce at hogranch.com>

m.roth at 5-cent.us wrote:
> I dunno, a buddy who was in army intel back in the early eighties told me,
> about 10 years ago, that they could flatten out the platters and read some
> data. Thermite not only melts the platters, but will hit the Curie point.
>   

in the 80s, disks held 10-20MB per 5.25" platter.  now they hold 300MB 
per 2 or 3" platter.   in the 80s, bits were written with simple MFM 
NRZI type recording techniques and the tracks were at absolute 
locations.   Today, the data is written with high density predictive RLL 
techniques and embedded servo

that said, my work has a policy of shreading/chipping/incincerating all 
old media.   any other sort of erasure/clearing is far too time 
consuming and labor intensive.    the old tapes, drives, etc are stored 
in a secure room, and once in awhile a data destruction truck comes by, 
and its all tossed into a giant chipper and comes out as ground scrap metal.