Re: How to zero a failing disk drive before disposal?

On Fri, 2024-10-11 at 13:42 +1100, Dewayne Geraghty wrote:
> I worked for a provider of services for the statutory care of children
> (eg removed from parents). [...] We bench-drilled the hard-disks
> before sending them (out of our chain of custody) to a furnace.

+1

> For personal devices we overwrite the device multiple times

After countless discussions about [1] and having recovered and not
recovered lost data myself, I am firmly convinced that it is sufficient
for a private household to overwrite just 1 time. After that Joe and
Jane Lunchbucket can't recover the data anymore and it's also quasi
impossible for a geek to recover something.

The problem with the Lunchbucket family's HDDs is that they only replace
them when they are defective anyway. At best, you can free up stuck
heads and be happy if you can get your 4 TB drive overwritten at all. In
these cases, the question of how often you should overwrite does not
even arise.

It is not for nothing that it is said that you should mount a drive
"read only" as soon as possible after data has been lost in order to
have any chance of recovering anything at all.

Criminals and secret services will think twice about whether it is worth
subjecting the Lunchbucket family's hard drive to time-consuming and
costly forensic treatment.

[1]
• rocketmouse@archlinux ~ 
$ man shred | grep -eiterations -eCAUTION -A1
       -n, --iterations=N
              overwrite N times instead of the default (3)
--
       CAUTION: shred assumes the file system and hardware overwrite data in place.  Although this is common, many platforms operate otherwise.  Also, backups and mirrors may  contain  unre‐
       movable copies that will let a shredded file be recovered later.  See the GNU coreutils manual for details.