smith said:
Modern hard drives have a "secure erase" option built-in. The
utility on this page, offers the ability to set the status bit
in the drive, that controls automated erasure. The idea is,
every time the drive is powered on, it works at the erasure
task. It won't stop erasing, until the entire disk is done.
So, in theory, you can set the bit, using the utility from
this web page, then hand the disk to someone else. The
drive will continue erasing, and ignoring external commands,
even while in the hands of the new buyer/user. Once the erase
command is complete, then the drive returns to normal operation.
http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml
For your usage, use the utility, set the bit, and watch the drive
light. The light should reflect the fact, that the drive
is autonomously busy and doing its thing. Wait until the
light goes out.
When the test is complete, use a disk editor utility to
examine the drive. Do some random seeks (near both ends of
the disk, at least), to verify it did the whole disk.
I would feel less comfortable, about the kind of drives that
use internal encryption. On those, setting the secure erase,
involves blowing away the key, and leaves the data as is. I
wouldn't feel comfortable relying on the encryption to keep
my data private. So for one of those drives, I'd also want
to do a pass with DBAN (unless the secure erase offered the
option to do it the "physical way").
As long as the drive light stays on for some number of minutes,
after setting the secure erase bit, I'd be reasonably satisfied.
Then I'd do a quick verify, using a disk editor.
Paul