I have a stack of old floppy disks in my server room and before disposing or donating them, I want to make sure they are cleaned. Can anyone suggest some free utilities (Windows or Linux) for securely wiping data from a floppy disk?
I use dban for mass wiping of disks, it supports all the major overwrite standards and has very good hardware support. However, modern research seems to indicate that a single zero pass wipe is sufficient for data destruction. In that case, you might as well just use a linux system and issue the following command:
dd if=/dev/zero of=/dev/fda
This will overwrite the floppy with all zeroes. Change the zero to urandom for a pass of random characters.
I usually use shred to wipe data. I think it's pretty reliable...
Eraser is a great free program that lets you wipe to a variety of different paranoia levels and standards. It also adds secure file deletion secure file move to the right-click menu in explorer... very handy if you do this stuff regularly.
Don't wipe them in software. Huge waste of time, considering the rate of bad blocks you'll have. If you must, format them, it has better error handling characteristics. Beware that some of the advice given will result in disks that are not wiped past the first bad block.
Run a strong magnet over them. Beware that the metal in a 3.5" disk can injure you (or if it can't, your magnet isn't strong enough).
Then throw them away. Any cause that is worthy of giving a donation to is not going to be helped by a donation of garbage. If there is an organization that takes donations of garbage to be used in art projects, I guess it makes sense to give the disks to them. It just sounds unlikely.
If you are running Windows 2000 or later, you can use cipher.exe (included with the OS) to securely overwrite deleted data on a drive.
Microsoft's KB article here: How To Use Cipher.exe to Overwrite Deleted Data in Windows
dban is very good. It can also wipe disks to a US Department of Defense standard. That should be fairly secure. :)
You can simply overwrite its content with random data multiple times with this simple bash script:
for i in $(seq 1 10); do echo pass $i; dd if=/dev/urandom of=/dev/fd0; sync; done
It goes through the disk and overwrites every sector with random data 10 times.
After that, you need to reformat the disk (probably for fat12).
If you are rescuing data from a such floppy, or try to re-use a floppy with bad blocks,
ddrescue is better as this simple script. It is in the package
gddrescue on most linux distros.