[CentOS] Utility to zero unused blocks on disk

Tue Feb 9 08:28:56 UTC 2016
Sorin Srbu <Sorin.Srbu at orgfarm.uu.se>

> -----Original Message-----
> From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On
> Behalf Of EGO-II.1
> Sent: den 9 februari 2016 09:00
> To: CentOS mailing list
> Subject: Re: [CentOS] Utility to zero unused blocks on disk
> >> the only truly safe way to destroy data on magnetic media is to grind
> >> the media up into filings or melt it down in a furnace.
> > I unscrew the casing, extract the disk platter(s), slide a very strong
> > magnet over both sides of the platter surface then bend the platter in
> > half.
> >
> > How secure is that ?
> >
> > I can't afford a machine that grinds everything into dust particles.
> I have seen a guy in the I.T. department where I  work take a hard
> drive....remove as many stickers from it (to make it porous as possible)
> and then soak it in a "brine" of ammonia, hydrogen peroxide, bleach, and
> salted water...for like a week or two. Afterwards? total useless junk.

I often find harddrives with several 10 mm drill-holes in them, in the 
electronics disposal room at work.

I'd say that'd be enough as well. 8-)