linux-kernel - Re: urandom is too slow

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Date:	Tue, 30 Oct 2012 21:38:50 +0000
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	"Theodore Ts'o" <tytso@....edu>
Cc:	Lasse Kärkkäinen <ljkarkk2@...hut.fi>,
	linux-kernel@...r.kernel.org
Subject: Re: urandom is too slow

> If you just want to wipe a disk, you shouldn't be using /dev/urandom for that
> purpose.

If you want to wipe a disk issue a security erase command via hdparm.
There is no guarantee that simply writing crap all over it will re-use
the same sectors of physical media, and for a flash drive it causes
massive wear and takes forever while a security erase is normally near
immediate.

Alan
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