On Wed, Sep 02, 2009 at 16:37:26 -0700,
"Dean S. Messing" <deanm(a)sharplabs.com> wrote:
Thanks to all for the replies.
I'll answer most of the comments here.
0) The disk is unmounted.
1) The drive is (was) a backup drive with a great deal of sensitive
corporate laboratory research data and algorithms on it. The
monitary loss of the data being stolen would be significant though
it's hard to put a $$ value on it. More importantly, I'm following
2) The drive is under extended warranty and so I'm sending it back for
a new drive. The Power Supply in the enclosure is bad. The actual
drive is still good, but they want the whole thing back for a
replacement. Sanding off the oxide and then melting the drive
probably won't go over well with the manufacturer.
Given 1, this seems like a foolish policy. Just eat the cost as part of
securing your data. It might be cheaper than having you keep an eye of
multiple write passes covering several days.
3) Writing zeros is a not a good idea if the data is valuable. The
small latent magnetic orientation info left from the previously
written data is not _that_ hard to recover with $5000 equipment, so
I've read. Multiple passes of random patterns are needed to make
There was some old documentation that claimed reading the remmants from
previous writes were recoverable, though I don't remember seeing costs
estimates that low. I would have expected a lot of human time needed to
help deal with the incomplete recovery.
If one can recover a significant amount of data after writing zeros, one
is going to be able to do it after writing a single pass of random data