Re: disk scrubbing

[David Brownlee <abs%absd.org@localhost>]

On Thu, 26 Aug 2021 at 13:32, Patrick Welche <prlw1%cam.ac.uk@localhost> wrote:
>
> Any thoughts on the pros and cons of
>
>    # cgdconfig -s cgd0 /dev/sd0e adiantum 256 < /dev/urandom
>    # dd if=/dev/zero of=/dev/rcgd0d bs=64k progress=512
>    # cgdconfig -u cgd0
>
> vs
>
>    # dd if=/dev/urandom of=/dev/rsd0e bs=64k progress=512

One is more typing and takes much longer to run? (and affects a
different partition :-p )

If its a flash device (or in fact any device which remaps blocks)
neither may overwrite all data, though both should frustrate recovery
short of flashing new device firmware or taking apart

The ATA "Secure Erase" or "Secure Erase+" commands _should_... though
we're trusting firmware here...

There may be something to be said for an ATA Secure Erase plus a dd of
urandom (or neb-wipe -r1)....

David