Gentoo Archives: gentoo-user

From: Rich Freeman <rich0@g.o>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Securely deletion of an HDD
Date: Sun, 12 Jul 2015 12:48:57
Message-Id: CAGfcS_k=0hn-c+YBM0YFTvqXWQZHJCU=fpCh587=FUJwipjyEg@mail.gmail.com
In Reply to: [gentoo-user] Securely deletion of an HDD by Marc Joliet
1 On Sun, Jul 12, 2015 at 8:35 AM, Marc Joliet <marcec@×××.de> wrote:
2 >
3 > My question is how precisely the disks should be cleared. From various sources
4 > I know that overwriting them with random data a few times is enough to render
5 > old versions of data unreadable. I'm guessing 3 times ought to be enough, but
6 > maybe even that small amount is overly paranoid these days?
7 >
8 > As to the actual command, I would suspect something like "dd if=/dev/urandom
9 > of=/dev/sdx bs=4096" should suffice, and according to
10 > https://wiki.archlinux.org/index.php/Random_number_generation#.2Fdev.2Furandom,
11 > /dev/urandom ought to be random enough for this task. Or are cat/cp that much
12 > faster?
13
14 I'd probably just use a tool like shred/wipe, but you have the general idea.
15
16 I'd probably follow it up with an ATA secure erase - for an SSD it is
17 probably the only way to be sure (well, to the extent that you trust
18 the firmware authors).
19
20 If it weren't painful to set up and complicated for rescue attempts,
21 I'd just use full-disk encryption with a strong key on a flash drive
22 or similar. Then the disk is as good as wiped if separated from the
23 key already.
24
25 --
26 Rich

Replies

Subject Author
Re: [gentoo-user] Securely deletion of an HDD Marc Joliet <marcec@×××.de>