Wiping a drive.
May 5, 2007 7:40 AM   Subscribe

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?
posted by 517 to Computers & Internet (18 answers total) 5 users marked this as a favorite
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.
posted by Steven C. Den Beste at 7:46 AM on May 5, 2007

I've had really good experience with DBAN (Darik's Boot and Nuke). Is there a reason you plan on reinstalling the OS?
posted by homer2k1 at 7:55 AM on May 5, 2007 [1 favorite]

Seconding DBAN.
posted by Blazecock Pileon at 7:58 AM on May 5, 2007

posted by Jairus at 8:05 AM on May 5, 2007

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.
posted by zamboni at 8:10 AM on May 5, 2007

Don't bother to reinstall your operating system before you sell the system.
posted by odinsdream at 8:13 AM on May 5, 2007

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.
posted by humblepigeon at 8:13 AM on May 5, 2007

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?
posted by 517 at 8:16 AM on May 5, 2007

The OS is windows XP.
posted by 517 at 8:18 AM on May 5, 2007

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.
posted by wackybrit at 8:19 AM on May 5, 2007

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.
posted by zamboni at 8:27 AM on May 5, 2007

For more on DBAN wipe times, see here.
posted by zamboni at 8:29 AM on May 5, 2007

Just last week on lifehacker, really wipe it.
"There is no data recovery from Secure Erase"
posted by raildr at 8:44 AM on May 5, 2007

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.
posted by odinsdream at 8:46 AM on May 5, 2007

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.
posted by Freaky at 10:31 AM on May 5, 2007

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)
posted by toxic at 3:25 PM on May 5, 2007 [1 favorite]

shred has a bad design. Use wipe instead.
posted by donut at 5:05 AM on May 6, 2007

Sorry. Missing proof.
posted by donut at 5:07 AM on May 6, 2007

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