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Recover HD Using a Magnet

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Re: Recover HD Using a Magnet

#3
post #2

How did the data not get destroyed by the magnet?

Yeah, this technique should really only be used if, and only if, you need the drive itself to be fixed and no longer care about the contents of the drive (e.g. if it was in a RAID 1 and manually cleared afterwards).

Re: Recover HD Using a Magnet

#4
post #2

How did the data not get destroyed by the magnet?

There are actually very powerful permanent magnets inside of every spinning hard drive already, so clearly there's more to destroying data than just having a magnet nearby.

https://www.kjmagnetics.com/blog.asp?p=hard-drive-destructio... has a writeup about trying and failing to wipe a drive with extremely powerful magnets.

Re: Recover HD Using a Magnet

#5
post #2

How did the data not get destroyed by the magnet?

It's changing magnetic fields that wipe HDDs. Such as powerful electromagnets.

In a clean (enough) room, they could have opened the drive, and just poked the actuator arm.

Decades ago, I had a HDD that wouldn't spin up unless I nudged the platter with a pencil erasor. Very near the center, of course. There was a hole in the case, in just the right place, with Al tape over it.

Re: Recover HD Using a Magnet

#6
post #2

How did the data not get destroyed by the magnet?

the whole magnet and hard drives thing is a really old hoax. with normal household magnets or even strong neodym magnets nothing will happen to your data but if you have a really strong industrial electro magnet at hand you can wipe a drive with it...

here is an old national geographics video on the topic https://www.youtube.com/watch?v=U8LWTe5CqQg

Re: Recover HD Using a Magnet

#7
post #6
post #2

How did the data not get destroyed by the magnet?

the whole magnet and hard drives thing is a really old hoax. with normal household magnets or even strong neodym magnets nothing will happen to your data but if you have a really strong industrial electro magnet at hand you can wipe a drive with it... here is an old national geographics video on the topic https://www.youtube.com/watch?v=U8LWTe5CqQg

Here's my anecdote:

In 2006, while sitting at my desk playing a video on the Travelstar 40GB PATA drive in my Thinkpad T22, I held a single neodymium magnet (harvested from an old hard disk drive) about 6 inches from the left side of the unit (where the ~disk was located). The video froze, Windows XP blue-screened, and the hard disk drive started emitting a ~10Khz whine. I jerked my hand away from the PC immediately when the whine started

BIOS would no longer detect the disk on that machine, or any other I tried it on (on both USB-to-PATA and honest-to-goodness motherboard PATA controllers). The drive spun up but made a repeated ticking sound (I assume seeking back and forth looking for servo tracks).

I sent the drive to Kroll Ontrack (because, stupidly, I had billing data that wasn't backed-up on the drive). The report I received back indicated that 80% of the drive's sectors were unreadable.

As an aside: The data I was looking for was ASCII text and Kroll Ontrack was completely unhelpful in just sending me a bitstream image of the drive so I could grovel thru looking for data I needed. Being plain ASCII, their "file carving" tools didn't locate any of the data. (They sent me a "preview" of the data they'd located, and while it got lots of Microsoft Office-format files, it didn't have any ASCII text files). I offered them a 3x multiple of the rate they asked for file-level recovery to simply send me the bitstream image of the disk that they'd already made. They wouldn't do it, and wouldn't even let me pay to talk to somebody who understood what I was asking for. I ended up taking a major loss on the billing data I destroyed. I'll never recommend them to anybody.

I won't ever play with neodymium magnets around spinning rust media again either. I also had a major failure of my discipline re: backup at that time, too. The cobbler's children always go barefoot-- I was being too cavalier with my backup strategy (or lack thereof) and not treating my own data like I would a Customer's.

Re: Recover HD Using a Magnet

#8
post #6

Earlier quoted context omitted.

the whole magnet and hard drives thing is a really old hoax. with normal household magnets or even strong neodym magnets nothing will happen to your data but if you have a really strong industrial electro magnet at hand you can wipe a drive with it... here is an old national geographics video on the topic https://www.youtube.com/watch?v=U8LWTe5CqQg

Here's my anecdote: In 2006, while sitting at my desk playing a video on the Travelstar 40GB PATA drive in my Thinkpad T22, I held a single neodymium magnet (harvested from an old hard disk drive) about 6 inches from the left side of the unit (where the ~disk was located). The video froze, Windows XP blue-screened, and the hard disk drive started emitting a ~10Khz whine. I jerked my hand away from the PC immediately…

Sounds like a coincidence.

Re: Recover HD Using a Magnet

#9
post #8

Earlier quoted context omitted.

Here's my anecdote: In 2006, while sitting at my desk playing a video on the Travelstar 40GB PATA drive in my Thinkpad T22, I held a single neodymium magnet (harvested from an old hard disk drive) about 6 inches from the left side of the unit (where the ~disk was located). The video froze, Windows XP blue-screened, and the hard disk drive started emitting a ~10Khz whine. I jerked my hand away from the PC immediately…

Sounds like a coincidence.

It does sound that way but, boy, it was eerily timed if it was.

Re: Recover HD Using a Magnet

#10
post #8

Earlier quoted context omitted.

Sounds like a coincidence.

It does sound that way but, boy, it was eerily timed if it was.

Magnetic field falls off with inverse cube of distance once you're past the approximate size of the magnet. Not to mention that the drive itself is in a ferrous enclosure that provides a lot of shielding... the magnetic field you applied at 6 inches is approximately nothing.
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