full-disclosure - Erasing a hard disk easily

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Message-ID: <200407141005.38407.fulldisc@ultratux.org>
From: fulldisc at ultratux.org (Maarten)
Subject: Erasing a hard disk easily

On Wednesday 14 July 2004 04:23, Aditya, ALD [ Aditya Lalit Deshmukh ] wrote:
> > I'm guessing that drilling a hole in the case, pouring in some sand and
> > firing up the disk would probably do a good job of rendering the data
> > non-readable too  ;>
>
> since the original poster only wanted to clean up the harddisk for
> donations so that no one can read the disks I think the Linux approach is
> the best one
>
>
> dd if=/dev/zero of=/dev/hd? ; dd if=/dev/urandom of=/dev/hd?

I agree.  But be advised that using /dev/urandom is several orders of 
magnitude slower than either /dev/zero or /dev/full, so if you're not 
paranoid or the data isn't that sensitive, you might want to opt for only 
writing zeros and ones instead...

maarten@...her:~> time dd if=/dev/urandom of=/dev/null  count=10000
10000+0 records in
10000+0 records out

real    0m4.770s
user    0m0.016s
sys     0m4.513s

maarten@...her:~> time dd if=/dev/zero of=/dev/null  count=10000
10000+0 records in
10000+0 records out

real    0m0.269s
user    0m0.020s
sys     0m0.019s

Maarten