Wiping hard drives

[stj]

Re: Wiping hard drives

if you use a magnet on a modern drive it's probably only good for the magnets afterwards.
you will erase the calibration data and config table. (size serial number etc.)

[fzabkar]

Re: Wiping hard drives

The Urban Legend of Multipass Hard Disk Overwrite:
http://www.infosecisland.com/blogvie...Overwrite.html

[fzabkar]

Re: Wiping hard drives

or a really strong magnet

One of the professionals at HDD Guru placed neodymium magnets all over the case of a HDD and was still able to retrieve all the data from it. The again, I have a massive 15cm x 16cm x 17cm voice coil magnet from a very old Control Data drive which would likely destroy any HDD. I should try it someday.

[keeney123]

Re: Wiping hard drives

if you use a magnet on a modern drive it's probably only good for the magnets afterwards.
you will erase the calibration data and config table. (size serial number etc.)

Sure would be nice if you could pop out the hard disk and use a degausser over it and then pop it back it.

[stj]

Re: Wiping hard drives

some drives have magnetic shields on the lid.

[keeney123]

Re: Wiping hard drives

So what I am reading is the drives can be recoverable with low level formatting, however you would have to have special equipment that the manufacturer has to do this. Seems like the servo codes get erased so the R/W head does not know where it is. I guess if you had the servo code you would be in business. That would be velocity/ acceleration/ position and a feedback for error correction. There is actually a mathematical formula for this. I have seen this done with just TTL ICs, no processor, no RAM, no ROM. Just TTY tape or Reel to Reel with TTL ICs

[fzabkar]

Re: Wiping hard drives

This article was written by a former Seagate employee:

http://hddscan.com/doc/HDD_Tracks_and_Zones.html

[keeney123]

Re: Wiping hard drives

This article was written by a former Seagate employee:

http://hddscan.com/doc/HDD_Tracks_and_Zones.html

Question could one burn a spiral track going from the outer edge using and equation for a given HD disk, spiraling around until it reaches the inside edge and use this to tell where the disk is at, perhaps have the laser deflect a differently angle on this one spiral to change the pick up frequency of the laser frequency so it knows that this is different from the other data. So spinning from one revolution to the next would position the head by electrically detecting and correcting the error.

[fzabkar]

Re: Wiping hard drives

HDDs use magnetic recording, not optical.

Heat Assisted Magnetic Recording (HAMR) is an emerging technology that augments magnetic recording by preheating the disc surface with a laser.

http://hddscan.blogspot.com.au/2011/...h-of-jedi.html

[keeney123]

Re: Wiping hard drives

HDDs use magnetic recording, not optical.

Heat Assisted Magnetic Recording (HAMR) is an emerging technology that augments magnetic recording by preheating the disc surface with a laser.

http://hddscan.blogspot.com.au/2011/...h-of-jedi.html

Yes I know they use magnetic recording, but could they not use a laser and a track like I said for alignment of the just the R/W head. I got a little confused between the optical drive and the Hard drive in the previous post for data retrieval I forgot magnetic heads don't pick up bumps on the surface and operate by magnetic charge. I wounder what happens when one sends light through a magnetic charge.

[keeney123]

Re: Wiping hard drives

Question could one burn a spiral track going from the outer edge using and equation for a given HD disk, spiraling around until it reaches the inside edge and use this to tell where the disk is at, perhaps have the laser deflect a differently angle on this one spiral to change the pick up frequency of the laser frequency so it knows that this is different from the other data. So spinning from one revolution to the next would position the head by electrically detecting and correcting the error.

Almost all the way through this article. Very interesting. Thanks fzabkar. It just seems there is a better way. I wonder if one had three disk one a read dish, one a write disk and in between a disk made up of read heads one side of this disk and on the other side a write head. This last disk would be the same size as the other two disk but would be loaded with R/W heads all over it. There would be no moving parts. Just a thought, which is what my mine constantly does, ask what if.

[fzabkar]

Re: Wiping hard drives

Current technology uses Dual-Stage Actuators. A regular rotary voice coil handles the coarse positioning while a piezo element provides fine positioning.

[keeney123]

Re: Wiping hard drives

Current technology uses Dual-Stage Actuators. A regular rotary voice coil handles the coarse positioning while a piezo element provides fine positioning.

Very interesting just adding 2 piezos create a small enough movement to create more accuracy.
I have been thinking about polarized laser light being applied to a dielectric causing a magnetic charge and having a magnetic wafer being magnetically charged to 1 bit and on the other side of the magnetic wafer is another dielectric that then interprets the magnetic charge and using a Xor in the input to output comparing to confirm the bit is a either a 0 or a 1.

[brethin]

Re: Wiping hard drives

Actually, it does include those. I have 4 of them. When I'm finished with the swapout, you're welcome to them.

They are still very usable, don't want to destroy them....otherwise, yes, they would become clay pigeons.

If you have any more SATA and SAS hard drives you consider clay pigeons please pop me a message, I am in need of these daily and would not expect them for free.