Degaussed Hard drive

[Skie]

Degaussed: putting Powerful magnet to a hard drive to erase data.


Ok so i've got a task. I've got a Hard Disk that has been Degaussed. From what i understand is the hard disk has notches inside the drive that reads and writes the information. When the hard drive is degaussed the notches are completely erased deleting all the data, making it basically useless. My task is to find out how to put the notches back, either by restoration (if possible) or manually doing it my self. So that the hard disk can be used again. So i figured i would ask the techy people. I dont have to actually do it i just have to find out how you would do it. Also i was told that NASA and other corporations use degaussing to clear their disk before they get rid of them. So i would assume that it would be impossible to get the data that was originally on the disk back, so at this point i just need to figure out how to get the notches back to where the hard drive can be used.

Also wouldent Degaussing like fry everything? not just erase the data?

[mootsfox]

What?

HDDs aren't records. They use magnetized tracks to store data, not groves. All degaussing would do is erase the data on the disks, not destroy them.

[Eliseos]

What?

HDDs aren't records. They use magnetized tracks to store data, not groves. All degaussing would do is erase the data on the disks, not destroy them.

This. The read/wriite head of a hard drive just polarizes the "bits" on the disk, either north or south, by sending a small magnetic field through. Passing an intense magnetic field over the entire disk would just polarize all the bits to being north or south. You would have no way of obtaining the original data back (to my knowledge, anyway).

[Skie]

what he was saying is like the servo-track gets erased when it is degaussed. He wants me to find out what i would need to do to rewrite the track or something. I dont need to actually recover the data (said would be impressed if i could find out a way to do it) but i just need to find out how you could rewrite the servo-track to use the HDD again

[Lhyet]

What sort of task is this for? o.O

I don't really know the mechanics of a HDD, but I can only assume you'd need some really powerful and really expensive hardware/software to get any data back from the thing, if it's even possible.

[Zosi]

Throw it in the garbage. You can't "manually" write servo control patterns, it's done by a special (read: expensive, specific and unavailable to you) machine at the factory.

[Skie]

i'm volunteering for professor at my college. he gave me a HDD and told me what to figure out how to get the track re written so that it works.

[Zosi]

i'm volunteering for professor at my college. he gave me a HDD and told me what to figure out how to get the track re written so that it works.

I'll rephrase: you can't. It's a process that's different for every model and requires information and equipment that nobody except the hard drive's manufacturer has. You can try asking them, but I suspect that at most, you'd get a replacement drive.

[Deadgye]

The way hard drives work is this: they're comprised of multiple paramagnetic metal platters. Small sections of these platters are set to either a positive charge or a negative charge. There's a small spindle that reads what the charge is, or writes to the section to change it. As positive and negative are the only two things that can be read, they are read as either 0 or 1 (binary). Data is stored by reading and writing these strings of 0s and 1s and turning them into something we can understand or view. Degaussing uses a powerful magnetic force to change all of the charges to the same exact thing, thus wiping out everything stored on the drive.

The servo-track information is, unfortunately, also stored as magnetic data. It is what allows the spindle to properly go through the small segments of the platters. What you have after degaussing a drive is a blank drive, it's pretty much useless, but not as useless as a broken drive.

[Zosi]

Degaussing shouldn't make the drive unusable, it should only permanently erase all the data. You cannot get the data back. If the drive isn't working, then I'm willing to bet that something more than degaussing happened to it.

The way hard drives work is this: they're comprised of multiple paramagnetic metal platters. Small sections of these platters are set to either a positive charge or a negative charge. There's a small spindle that reads what the charge is, or writes to the section to change it. As positive and negative are the only two things that can be read, they are read as either 0 or 1 (binary). Data is stored by reading and writing these strings of 0s and 1s and turning them into something we can understand or view. Degaussing uses a powerful magnetic force to change all of the charges to the same exact thing, thus wiping out everything stored on the drive. There's no reason it should make the drive unusable.

You left out the rather important part that explains why degaussing a hard drive actually *does* make it completely unusable. At the factory, a magnetic pattern is printed on the platters that numbers each sector so that the read/write head can seek accurately. This is called the "servo guide pattern". Degaussing wipes this out, and without it, it's completely impossible for the drive to function.

[Deadgye]

I edited 8 minutes before you posted, I don't know if I can even call this a ninja edit.

[Zosi]

I edited 8 minutes before you posted, I don't know if I can even call this a ninja edit.

I wasn't even going to say anything about it, but since you decided to start something... Urban Dictionary defines a "ninja edit" as:

A ninja edit is an change made to a published post or article (typically on a bulletin board) that preempts the first response made. Often, the existence of the ninja edit is only made clear by a reference to the mistake or inconsistency in the original article by the response. In such a case, the author of the response began writing before the ninja edit, but submitted the response after the ninja edit had been made.

If someone notices the original text and starts responding, it's a ninja edit, particularly when you try to hide the mistake rather than put a nice, friendly "Edit: Sorry, initial post was wrong, fixed it" at the end. Now, can the thread continue, or are you going to keep shitting it up trying to ?

[Khamsin]

Degaussed: putting Powerful magnet to a hard drive to erase data.

Wouldn't putting a powerful magnet to a hard drive magnetize it, not degauss (demagnetize) it? Maybe it would be called 'gaussing'?

[Deadgye]

I wasn't even going to say anything about it, but since you decided to start something... Urban Dictionary defines a "ninja edit" as: [ninja edit]

I was referring more to the fact that it took you 8 to 15 minutes to respond with your response. It's just not really ninja-esque when it's not all sneaky. How you got it into your head that I was trying to start something is beyond me.

particularly when you try to hide the mistake

Particularly in this context would mean referring to my situation. There was no attempt to hide any mistake in this situation, so once again I don't know where you got this from. I did not once ask you to remove your quote, or insist that you quoted me incorrectly, or anything else of the sort.

rather than put a nice, friendly "Edit: Sorry, initial post was wrong, fixed it" at the end.

There was very little reason to include an edit notification, specifically one stating that the original message was incorrect, particularly since the edit was made within 6 minutes of the initial post and there were 0 responses to it. I could have went back to add the edit message after your post, but that would just be plain silly.

Now, can the thread continue, or are you going to keep shitting it up trying to :saveface?

The only one shitting up the thread up until this point is you. I would have no reason to continue your shitting up of the thread, if you never started. (To clarify for you, I am talking about this post that I am quoting, not your first one quoting me.) I have yet to make any attempt to save face.

What I said originally was wrong; after confirming that it was wrong I changed it. It's as simple as that. Why you had to assume that I was doing something I was not, and saying something I in no way implied, is once again beyond me. If you're taking a simple sarcastic comment as "starting something" I think it's time to take a short break from the forums.

Wouldn't putting a powerful magnet to a hard drive magnetize it, not degauss (demagnetize) it? Maybe it would be called 'gaussing'?

Degaussing, like other words, doesn't just have one definition. Among the list are "To neutralize or rebalance the magnetic field of a magnetized object" and "To erase information from a magnetic disk, tape, or other magnetic storage device." It's using one of those definitions in this case.

[Skie]

drop the bull shit plz im asking for information not drama.

Anyway from what i've gathered is that when a HDD is degaussed the magnetic spindles on the platter are rearranged erasing all the information, making it impossible to retrieve. furthermore when a HDD is degaussed it is vertically useless. I may be possible to get the sirvo-track rewritten but its not something that can be done at home or a low end lab, it would have to be sent to the manufacturer to be done. Is this correct?

[Deadgye]

drop the bull shit plz im asking for information not drama.

Anyway from what i've gathered is that when a HDD is degaussed the magnetic spindles on the platter are rearranged erasing all the information, making it impossible to retrieve. furthermore when a HDD is degaussed it is vertically useless. I may be possible to get the sirvo-track rewritten but its not something that can be done at home or a low end lab, it would have to be sent to the manufacturer to be done. Is this correct?

Yeah, this is what the credible sources seem to indicate. (lolwikipedia and Zosi)

[Jodwahh]

Wouldn't putting a powerful magnet to a hard drive magnetize it, not degauss (demagnetize) it? Maybe it would be called 'gaussing'?

Yeah I gauss you could call it that.


OHOHOHOHOHO

[Zosi]

Yeah, the manufacturer would be the only place that could do it, and even they might not bother. It's not a data recovery operation, so the end result of them spending a few man-hours to take the drive apart in a clean room and send it back through half the manufacturing process would just be an empty drive, just like the countless ones that roll off the assembly line every day. They'd probably just send you a new one, if they helped you at all.

Yeah I gauss you could call it that.


OHOHOHOHOHO

I gave you an internet for that horrible joke, use it well!

[SubzeroDiabolos]

I gave you an internet for that horrible joke, use it well!

Holy fuck troll. You're helping people in tech, do you really have to be an ass doing so? Seems contradictory to me to say the least.

[Purrrfect]

Holy fuck troll. You're helping people in tech, do you really have to be an ass doing so? Seems contradictory to me to say the least.

Lol, Zosi's last line was also a joke.

edit: also, vertically useless^^