Wiping data off hard drives

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milomak

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Seeing the recycling thread reminded me I have some hard drives I no longer need (100GB and less). Now before I distribute these babies I want to wipe them clean.

Are there any non-commercial tools (preferably Linux) that will do a good job of this?

I need a method that basically would just make someone who is tech savvy enough not interested in going through the schlep of trying to see what might have been on there. I’ll take my chances that some hi-tech government agency won’t get hold of them.
 
http://www.oak-tree.us/blog/index.php/2009/03/20/scrub-pc
One of the nasty secrets of the computer world is that even when you delete a file, it isn’t really gone. Instead, the computer marks the space as available will overwrite it at some time in the future. But all of the data is still there, ready for anyone to look at it, provided they know how.

When it comes time to dispose of an old computer, this can be a major problem – especially if the computer held sensitive data like patient records, personnel reports or financial information. Short of smashing the hard drive with a hammer, the best way to destroy the information is by overwriting the entire hard drive several times with unreadable gibberish; a process known as scrubbing.
Click to expand...
 
ponder said:
If the drive is full how long does the procedure take? SecureErase is the fastest way I know of.
Click to expand...

amongst them i have an 8GB HDD. I'll first start with that one to try and get an idea.
 
milomak said:
Seeing the recycling thread reminded me I have some hard drives I no longer need (100GB and less). Now before I distribute these babies I want to wipe them clean.

Are there any non-commercial tools (preferably Linux) that will do a good job of this?

I need a method that basically would just make someone who is tech savvy enough not interested in going through the schlep of trying to see what might have been on there. I’ll take my chances that some hi-tech government agency won’t get hold of them.
Click to expand...

If you're CPT based, my torrent box needs some replacement IDE drives. I'm not savvy (or dodgy ;)) enough to try to abuse your generosity should you see fit to throw a couple my way.
 
We've been using EraserPortable for this very reason for a while now and it works very well. I've tried recovering drives that have been erased with it before but couldn't. It fits on a USB stick, or even CD so all the techs have a copy with them all the time.
 
There is also dd:

In Linux type: (Also possible on FreeBSD, Solaris with small variations)
First get device names using:
Code: 
sudo fdisk -l
Which should output something like this:
Ubuntu: dd said:
Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00012a28
.....
Click to expand...
Code: 
sudo dd if=/dev/zero of=/dev/DEVICENAME bs=1M
replace DEVICENAME with what you got using fdisk -l, eg. /dev/sda

That will fill the entire disk with zeros, just remember this will remove EVERYTHING, every single bit will be zero.

In Windows (191kb to download):
Code: 
dd --list
which will give you the devices you have

Example:
dd said:
......................

\\?\Device\Harddisk0\Partition0
link to \\?\Device\Harddisk0\DR0
Fixed hard disk media. Block size = 512
size is 640135028736 bytes

Virtual input devices
/dev/zero (null data)
/dev/random (pseudo-random data)
- (standard input)
.........
Click to expand...

As you can see I only have a hard-drive (removed some other stuff for sake of space). To set every single BIT on the hard-drive to zero I would then type:
Code: 
dd if=/dev/zero of=\\?\Device\Harddisk0 bs=1M --size --progress

After it is complete the hard-drive is filled with zeros. You can also use /dev/random if you want random data instead

You can also use this application to create images, bit by bit of a hard-drive
eg:
Code: 
dd if=\\?\Device\Harddisk0 of=D:\test.img bs=1M --size --progress
 
Last edited:
ponder said:
Gnome, using dd is slow.
Click to expand...

Hence the 1MB bit setting, should speed it up a bit :p

But true, generally not the fastest way to do it. Do you know of alternative programs that can ZERO fill an entire hard-drive at a much faster speed?

Generally I do a zero fill every 2 years or so when I'm going to format, for some reason it works well for bad sectors (probably because the bad sectors are discovered marked and relocated).
 
Heh, should have read before (When you posted). Awesome, didn't know that, thanks! Put this in my permanent bookmarks, definitely going to be handy
 
Gnome said:
Heh, should have read before (When you posted). Awesome, didn't know that, thanks! Put this in my permanent bookmarks, definitely going to be handy
Click to expand...

There are a few utilities that use the same ATA Secure Erase command, MHDD & Victoria are free ones that come to mind but they do way more than that and can be dangerous in the wrong hands. If you use linux you can also access the feature via the hdparm command.

http://advosys.ca/viewpoints/2006/07/hard-drive-secure-erase/ Some background info besides the previous link I posted
https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase for people that use linux
 
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