Cleaning the Slate

September 8, 2007 7:54 PM

What's the best way to wipe a hard drive clean?

I've got an old Dell desktop model that I want to sell, but before I do I need to erase all of the data on the hard drive.

posted by Poolio to computers & internet (12 comments total)

shred works, comes with cygwin, seems relatively paranoid, and is free.
posted by orthogonality at 8:00 PM on September 8, 2007 [1 favorite has favorites]

here and here

via
posted by special-k at 8:02 PM on September 8, 2007 [1 favorite has favorites]

Boot from a Linux floppy (LOAF (Linux on a Floppy) is good for this). Run this:

dd if=/dev/zero of=/dev/hd0

This will write your hard drive with all zeroes. Done.
posted by SansPoint at 8:03 PM on September 8, 2007 [1 favorite has favorites]

Thanks everyone.

Those links look really helpful, special-k.
posted by Poolio at 8:05 PM on September 8, 2007

dban is your solution. Make a floppy (or CD or USB drive), let it boot into Linux and wipe the disk. Done.
posted by Nelson at 8:09 PM on September 8, 2007 [3 favorites has favorites]

Thanks, Nelson. :)
posted by Poolio at 8:12 PM on September 8, 2007

You're welcome Poolio!
posted by special-k at 8:13 PM on September 8, 2007

shred works, comes with cygwin, seems relatively paranoid, and is free.

The OP doesn't indicate which filesystem s/he is using, but NTFS, ext3 are both journaled file systems.

CAUTION: Note that shred relies on a very important assumption: that the file system overwrites data in place. This is the traditional way to do things, but many modern file system designs do not satisfy this assumption. The following are examples of file systems on which shred is not effective, or is not guaranteed to be effective in all file system modes:

* log-structured or journaled file systems, such as those supplied with AIX and Solaris (and JFS, ReiserFS, XFS, Ext3, etc.)
* file systems that write redundant data and carry on even if some writes fail, such as RAID-based file systems
...

-- via shred's man page

The man page goes on to say that it won't work with NFS, or compressed file systems either.

DBAN is the solution.
posted by philomathoholic at 8:53 PM on September 8, 2007 [1 favorite has favorites]

If the buyer expects to receive a bootable computer, dban et al. will require that you reinstall the operating system, so make sure you have the install CD available before you wipe the box.
posted by dws at 8:59 PM on September 8, 2007 [1 favorite has favorites]

Thanks for that bit of info, dws.
posted by Poolio at 9:02 PM on September 8, 2007

DBAN works, but I also like Active KillDisk which has a free version available (see link).
posted by limon at 12:41 AM on September 9, 2007 [1 favorite has favorites]

I think DBAN is pretty fantastic.
posted by oaf at 5:01 AM on September 11, 2007