hacked by the (alleged) `amazon-security' scammers

[Slade Watkins]

Hey there,

On Sun, Nov 7, 2021 at 11:01 AM Ralf Mardorf via ubuntu-users
<ubuntu-users at lists.ubuntu.com> wrote:
>
> On Sun, 07 Nov 2021 10:22:24 -0500, hput via ubuntu-users wrote:
> >Anyone here that can coach me a little about how to go about getting
> >the disks securely wiped.
>
> Hi,
>
> you much likely can't do that. All drives (not only shingled magnetic
> recording hard disk drives and solid state drives) manage storage by the
> firmware. Drives have got zones with copies of data, that you can't
> access targeted by the host's software. Using manufacturer utilities
> might be able to do the job, but I wouldn't trust those tools.
>
> If you should consider to use shred...
>
> $ apropos shred
> shred (1)            - overwrite a file to hide its contents, and optionally delete it
>
> ...overwriting items just one time is enough. It makes not much sense to
> overwrite items several times.

I'd like to second this. If you want to do it twice to make sure,
that's fine, but anything more than 1 or 2 times is enough.

>
> "Limitations
> A limitation of shred when invoked on ordinary files is that it only
> overwrites the data in place without overwriting other copies of the
> file. Copies can manifest themselves in a variety of ways, such as
> through manual and automatic backups, file system snapshots,
> copy-on-write filesystems, wear leveling on flash drives, caching such
> as NFS caching, and journaling. All limitations imposed by the file
> system can be overcome by shredding every device on which the data
> resides instead of specific files. However, since wear leveled devices
> do not guarantee a fixed relationship between logical blocks
> addressable through the interface and the physical locations in which
> the data is stored, shredding may not provide adequate security. If
> available, the SATA secure erase command, issued through hdparm or a
> similar utility, may be helpful in this situation. Even for magnetic
> devices, SATA secure erase will be faster and more reliable than
> shredding. Physical destruction may be necessary to securely erase
> devices such as memory cards and unusable hard disks." -
> https://en.wikipedia.org/wiki/Shred_(Unix)#Limitations
>
> Regards,
> Ralf
>
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             -slade