Comments on: Wiping a drive.

Question: Wiping a drive.

517 — Sat, 05 May 2007 07:40:58 -0800

I am trying to wipe my hard drive...

so that I can sell it. I have a copy of Killdisk and a copy of my OS but I get the feeling there is more to the task than wiping the drive and reinstalling the OS. Does anyone have any experience with this?

By: Steven C. Den Beste

Steven C. Den Beste — Sat, 05 May 2007 07:46:04 -0800

The usual approach is to low-level format the drive. Some think you should do that several times.

Low-level formatting takes a long time. Any "format" operation that doesn't take hours isn't a low-level format.

By: homer2k1

homer2k1 — Sat, 05 May 2007 07:55:31 -0800

I've had really good experience with DBAN (Darik's Boot and Nuke). Is there a reason you plan on reinstalling the OS?

By: Blazecock Pileon

Blazecock Pileon — Sat, 05 May 2007 07:58:13 -0800

Seconding DBAN.

By: Jairus

Jairus — Sat, 05 May 2007 08:05:43 -0800

DBAN.

By: zamboni

zamboni — Sat, 05 May 2007 08:10:51 -0800

No, that's pretty much it. DBAN or similar will take care of the overwrite and reformatting. (I'm assuming killdisk is something similar.) on preview, 4thing DBAN.

By: odinsdream

odinsdream — Sat, 05 May 2007 08:13:18 -0800

Don't bother to reinstall your operating system before you sell the system.

By: humblepigeon

humblepigeon — Sat, 05 May 2007 08:13:25 -0800

You can use the 'shred' command in Linux. Just boot from a Linux live CD (ie an Ubuntu install CD), and type the following in a terminal window:

shred /dev/hda

if it's an EIDE drive, or for a SATA drive type

shred /dev/sda

Both these two commands assume only one drive in the computer, or that you're trying to wipe the first drive. For safety, I would temporarily disconnect all but the drive you want to wipe.

Shred is supposed to overwrite data enough times to make recovery impossible.

By: 517

517 — Sat, 05 May 2007 08:16:34 -0800

I plan on reinstalling the OS to make it easier to sell.

So if I use DBAN, I can just install the OS after it's done, I won't have to partition, format, whatever?

How long does it take for DBAN to wipe a disk?

By: 517

517 — Sat, 05 May 2007 08:18:58 -0800

The OS is windows XP.

By: wackybrit

wackybrit — Sat, 05 May 2007 08:19:10 -0800

Just to point out, but you should never "low level format" a modern drive.

I believe SCdB is referring more to overwriting all of the data (usually multiple times) in order to prevent future access to it, rather than actual "low level" formatting.

By: zamboni

zamboni — Sat, 05 May 2007 08:27:34 -0800

How long?

Depends on the size of the disk, the kind of computer you have, and the wipe level. Guttman is probably overkill - DoD or DoD Short are probably sufficient for your needs.

By: zamboni

zamboni — Sat, 05 May 2007 08:29:29 -0800

For more on DBAN wipe times, see here.

By: raildr

raildr — Sat, 05 May 2007 08:44:24 -0800

Just last week on lifehacker, really wipe it.
"There is no data recovery from Secure Erase"

By: odinsdream

odinsdream — Sat, 05 May 2007 08:46:11 -0800

Yes, you can reinstall the OS after running DBAN. You won't have to personally do any partitioning since the Windows installer will take care of it automatically.

If you do plan to sell it with the operating system, be sure the product key goes with it, and that you don't reuse the key later yourself.

By: Freaky

Freaky — Sat, 05 May 2007 10:31:30 -0800

If you don't want it to take days and you're not particularly worried about someone taking an electron microscope to your disk to recover a few fragments of your porn collection, a simple "dd if=/dev/zero of=/dev/sda bs=1M" or similar will be sufficient (in file=system "zero" pseudo-device, out file=SCSI disk a, block size=1 MB). if=/dev/urandom (unlimited [pseudo-]random device) is slightly "better", but may be slower.

If you want to do it from within Windows, unmount the drive with Disk Manager and use dd for Windows in much the same way.

By: toxic

toxic — Sat, 05 May 2007 15:25:28 -0800

DBAN works well, but most modern drives have a special "secure erase" command built in that works even better. (This has been part of the S.M.A.R.T./ATA specification since 2001 or so, so all drives built after then should support it). Who says it's better? NIST for one.

The folks at the UCSD Center for Magnetic Recording Research have a small utility called Secure Erase that will let you issue this command to your drive(s). You can download it by clicking on the link on the left side of this page. (via)

By: donut

donut — Sun, 06 May 2007 05:05:26 -0800

shred has a bad design. Use wipe instead.

By: donut

donut — Sun, 06 May 2007 05:07:45 -0800

Sorry. Missing proof.