Comments on: Erase that hard drive!

By: daniel

daniel — Tue, 05 May 2009 02:27:30 +0000

i agree with Mr. sledgehammer

By: ratty

ratty — Sat, 29 Sep 2007 02:32:15 +0000

To day I have 8 commercial drives to wipe, I elected to swirl a “very” powerful bar magnet around the disk area 10 times in each direction and test the result. Magnet 60mm x18mm x 140mm. strong enough tho pick up a steel garden spade. ( sorry dont have a gaus meter).
The magnets from inside a hard drive would be strong enough, they are massivly strong for there size.
The partitions and data were gone, but the drives remain usable after partitioning and formating.
It is possible that bits of data remain and could be recovered but they would be scrambled fragments and the cost of recovering them would be prohibitive to all but the crimanaly obsessed or the police ferensic team desperate for a clue.
In the extreme data recovery world, electrons microscopes can be used can on bent fragments of disk.
If you can conceive of a strong magnetic field and tiny magnetic particales being pulled around 360 degrees several times then you understand the process I use.
Its only a matter of magnetic strength, proximity and motion.
The true paranoid need to grind the platters into powder, the rest of us need to use common sense and try not to waste recourses by recycling drives.
Ratty

By: John C. Randolph

John C. Randolph — Tue, 27 Mar 2007 21:06:52 +0000

Will it BLEND?

Saves time, and it’s far more entertaining.

-jcr

By: bbum’s weblog-o-mat » Blog Archive » Magnetic Finger: A Sixth Sense

Tue, 27 Mar 2007 07:54:33 +0000

[...] chat today and, somehow, the conversation turned to magnets. Maybe it was because I got called a complete idiot by the clue [...]

By: Fascination Place » Old Computer Junk

Fascination Place » Old Computer Junk — Sat, 24 Mar 2007 23:07:40 +0000

[...] I bought back in 2001. It’s now been replaced twice and is not used at all. I’m being 7 times more paranoid than bbum and doing a 7-pass zeroing erase on the drive. Once that’s done, I’m just going to [...]

By: bbum

bbum — Sat, 24 Mar 2007 18:59:09 +0000

Good song and a good way of erasing a drive. Tends to powder those useful rare earth magnets, though.

By: gojohnnygo

gojohnnygo — Sat, 24 Mar 2007 07:16:24 +0000

Sledgehammer.

By: bbum (waiting for panic'd machine to reboot)

bbum (waiting for panic'd machine to reboot) — Fri, 23 Mar 2007 21:02:13 +0000

Hah.

First, the incredibly powerful magnets off to the sides of the platters are extremely precisely engineered to shape the magnetic field such that it is effectively contained. Most are in the form of a little sandwich and, when assembled, there is very little field leakage. So little that the magnet assembly will typically not stick to a refrigerator whereas the isolated magnets not only stick, but are hard to pull off.

Secondly, hard drives and floppies are not as susceptible to magnetic fields as you might think. The presence of a weak and relatively constant field won’t erase data. A moving field is key and taking a really powerful fixed magnet and waving it over the surface works quite well. Degaussers work even better as they use AC current to produce a constantly moving — collapsing and expanding, actually– magnetic field that erases the data.

If I really care, I destroy the platters (or use them for other purposes immediately which, invariably, results in them being bent and scratched). Otherwise, the above will erase the data plenty well enough that only a seriously interested party with a pretty hefty budget would be able to restore the data.

Hell, you are talking about drive platters that have been removed from their clean room hard drive environment. That, alone, effectively makes the data inaccessible to all but the very most interested parties.

Since I don’t browse kiddie porn, run a crime ring, or have bazillions of dollars in offshore bank accounts, I’m pretty damned sure that said “most interested parties” would find a lot more attractive targets than me.

Oh, finally, if you are going to be calling people idiots, get a clue first. Calling someone an idiot when you are, in fact, wrong doesn’t reflect well upon you.

By: M$Worker

M$Worker — Fri, 23 Mar 2007 20:47:34 +0000

you are an absolute idiot by the way. running a magnet over the plates will not do anything to your data. think about what you said…..”I run one of the magnets over them upon removal”, but yet INSIDE the hard drive, along side of the platters lays the MAGNETS…so obviously running the magnet over the platters wont effect them at all. hopefully you do some research or know what you are talking about before you go chattering.

By: Charles

Charles — Sun, 18 Mar 2007 22:59:26 +0000

I have an old VHS tape eraser, it runs off 120v AC current and its magnetic field is strong enough to lift heavy objects. The theory is that it uses alternating magnetic fields, so it’s better at erasing than a solid magnet. This should be the ultimate hard drive eraser, as it would erase the platters right through the metal case, and not just the data tracks, but also the servo tracks that tell the drive R/W head where to position itself. But I’ve never tried this, believe it or not, I’ve never thrown away a hard drive, they’re all still sitting in my closet!