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Date: Wed, 8 Aug 2012 14:02:10 +1000
Message-ID: <CAC=wYCGrpLu38xfjD73q2=UwnUqys-5bj1yoZdbrjgduMWo=yg@mail.gmail.com>
Subject: Re: [gentoo-user] Want to seriously test a NEW hard drive
From: Adam Carter <adamcarter3@gmail.com>
To: gentoo-user@lists.gentoo.org
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> I have seen where people use dd to do this sort of thing to.  I read
> somewhere that if you do a dd and put in all 1's, then all 0's then back
> again that it is very hard to get any data back off the drive.  I think
> if you do it like over a dozen times, it is deemed impossible to get
> anything back.  I think that is the Government standard of it's gone.

I've heard the old attacks to recover data from a zerod drive are no
longer viable for disks of greater capacity than about 10G. I haven't
seen the information myself, however.

A single pass using dd would probably a good way of detecting any
existing bad blocks, so a smartctl then dd then smartctl again and a
diff of the results may be interesting.

I just use a 1TB software mirror for my backups.