Shredding a hardisk

[John N]

Nothing will beat the speed of this shredder rosie...

I suspect Rosie would have a hard time of it. You'd need a much more serious shredder. I've used a bandsaw (kind of fun), but usually I just drill a hole in them. ;-)

Oh, back in service... Unless you got something you are real paranoid about, simply either:

1) Usually putting on a new filesystem and filling it up:
1a) Linux: mkfs -t ext2 /dev/hda ; mkdir /tmp/1 ; mount /dev/hda /tmp/1 ; mkfile 100g /tmp/1/myfile
or
1b) mkfs -t ext2 /dev/hda ; mkdir /tmp/1 ; mount /dev/hda /tmp/1 ; dd if=/dev/zero of=/tmp/1/myfile bs=1024 count=1000000)
2) zeroing the drive prior to reformatting (dd if=/dev/random of=/dev/hda ; mkfs -t ext3 /dev/hda).

Should be fine. The ability to read data back from overwritten data is pretty special and I wouldn't sweat it too much.

Old data can be restored from a hard drive that has been fdisked and formatted. Even if a new OS is installed over top.

Look for something that can do 7 passes and mix up what it is writing on each pass. Not just all 0's or 1's.

Reference for something that does this?

-john

 

[gorn]

Norton Utilites at least in the old days included a program called Gdisk. It is fantastic for removing data from a hard drive. You can do it fast, DOD spec, or custom passes. It is what we used at the taskforce I worked at when we had to wipe hard drives that had illegal data on them.

 

[Marduke]

Norton Utilites at least in the old days included a program called Gdisk. It is fantastic for removing data from a hard drive. You can do it fast, DOD spec, or custom passes. It is what we used at the taskforce I worked at when we had to wipe hard drives that had illegal data on them.

UBCD had Gdisk on it, among many other tools that will wipe the disk multiple times.

 

[snakebite]

+2 on ubcd/dban.
a pass with dban and tla's will give up in disgust trying to recover anything.
just overwriting with a new o.s will destroy existing data since it will be costly to recover.
btw you would be shocked at what i have found on the harddrives of pc's found on the curb.yikes!

 

[Rothrandir]

Thanks guys, sorry it took so long to get back.

I downloaded the Ultimate Boot disk, but Dban wanted a floppy to work, which I did not have. So I just used Killdisk (I think...) which was on the disk as well, and it seemed to work fine. The computer is in an area where it may be used by other people, so I figured I'd give it a rinse down while I was in the process of redoing everything. Only took about 20mins with the killdisk, and the re installation went without a hitch. My memory may be off, but I seem to remember the last time I tried to redo this computer, It had some issues. Maybe wiping it helped?
The computer was purchased used about 4 years ago...

 

[Fallingwater]

Download this and burn it to a CDRW (or CDR if you don't mind wasting a 700mb disc for 50mb of data).
Boot the machine from that, and at the cursor prompt type
dsl 2 <enter>
This will boot in text mode rather than in graphical interface.

Wait for the system to boot, and at the prompt do the
dd if=/dev/zero of=/dev/hda
trick that was explained above.

It'll wipe all data, including boot and partition information.

 

[LuxLuthor]

A simple "low level format" command with any of these various utilities writes zeros to every bit, and restores a HD to its fresh, minty, out of the box state. It doesn't matter if you use a CD utility with a text or graphical interface presentation.

 

[gorn]

A simple "low level format" command with any of these various utilities writes zeros to every bit, and restores a HD to its fresh, minty, out of the box state. It doesn't matter if you use a CD utility with a text or graphical interface presentation.

Data can be recovered from a drive that has been re-formated.

 

[matrixshaman]

I've been able to recover drives that were both repartitioned and formatted. Even low level formatting can be recovered by NSA types but I don't think that's what you are concerned with. However if you were a multi-pass low level formatter with random pattern writes should do the trick if it is written enough times. Otherwise most of the suggestions above will keep you safe from the average hacker.