Re: RHEL/CentOS compatible, DOD grade disk scrubber tool desired



On 2011-02-14, David W. Hodgins <dwhodgins@xxxxxxxxxxxxxxxxx> wrote:
On Mon, 14 Feb 2011 15:20:28 -0500, Nico Kadel-Garcia <nkadel@xxxxxxxxx> wrote:

I'm dealing with a whole stack of disks to decommission, to "DOD

There is no such thing.

If you really want to destroy them-- shred them, and then heat the scrap to
about 700C.


I would expect that to require destruction of the media, or at least
electromagnetic bulk erasing, including all timing marks.

Bulk erasing is useless. The remnance of disks is far too high (on
purpose) You cannot make the field high enough to collapse a domain.
But heat will do it ( heat to above the ferromagnetic transition and all
the domains will be gone).



Is there a Linux compatible tool out there that someone can recommend
for use from a bootable CD image for these systems?

a Linux compatible fire?

If you really really want to reuse the disk, just overwrite it once with
anything-- including all nulls . Modern disks squeeze every last ounce
of information content out of the disks-- if there really were a way
that 01 (0 now, 1 previously) were differnt from 00 (0 now 0 previously), they would use that
difference to store information on the disk.

That old disks did have a detectable difference between 0 now and 1 or 0
perviously was because they were at a pretty unsophisticated part of the
development cycle. Why do you think we now have terrabytes on disks much
smaller than a 10MB disk 15 years ago? redundant information ( except
that purposely built in in order to pretty high order error correction)
is pretty hard to find on the disks now, as I understand it.

Ie, if the data is sensitive enough to worry about unknown ways of
retrieving it from an erased disk, then destroy it, and heat it to
destroy all the magnetic domains. If it is not that sensitive, just
overwrite it.





I'd just go with "dd if=/dev/urandom of=/dev/fd0 bs=4096", to overwrite
the floppy. Repeat as many times as you are willing to wait for.

Agree. but
Floppy? Was he referring to floppies? I thought it was hard disks.
floppies burn nicely. Just burn them.


Replace fd0 with hda, or sda, as appropriate, if you are referring
to hard drives.

Regards, Dave Hodgins

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