HDD Data Loss & Magnets

Discussion in 'OT Technology' started by OFI, Nov 13, 2009.

  1. OFI

    OFI New Member

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    Just been discussing this and can't get a confirmed answer..

    Magnets CAN cause data loss in HDDs but what sort of sized magnets are we talking about?

    As eHow says:

    But it doesn't say you won't get ANY loss.

    Want to know if it would be safe to have a laptop near a large speaker :o

    "Closer to the strength of an electromagnet" is a bullshit term too. You can make them any strength you want..
     
  2. crontab

    crontab (uid = 0)

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    i don't know how strong the magnet's need to be, but they do have to be pretty strong.

    we have an ancient tape degausser that feels as if it's going to explode when you turn it and it didn't effect any of the drive i've tested it on. it did wipe some old tapes.

    we do have a drive destroyer that does degauss the drive and then bends it in half. the guys who use that say they don't have any way of recovering the data even after that degauss, even with something like the Data Compass.

    even if the speaker/magnet isn't strong enough to clear the platters, it may have an effect on the head. it could bend them a few nm in the wrong way causing a crash or it may throw of the two magnets inside that control the head too.
     
    Last edited: Nov 13, 2009
  3. OFI

    OFI New Member

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    Yea that's wht i'm worried about. I'm quite sure it won't kill it but i'm not happy with any data loss at all. Will have to keep the laptop out of my boot!

    I know the government uses the magnets from nuclear reactors to wipe theirs..
     
  4. crontab

    crontab (uid = 0)

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    there must be a disconnect in my terminology, because I don't know what keep the laptop out of my boot means.
     
  5. DigiCrime

    DigiCrime If Only!

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    Fairly large one I think. Typical magnent if left on a hard drive for long periods of time might do the trick but in a fast pace recycling production a large magnent is used I'm guessing.
     
  6. Harry Caray

    Harry Caray Fine purveyor of x.264, h.264 & TS HD-Video !!! HD

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    I have an big'ol strong magnet from a surplus shop... when I put it next to a HD, it starts to whine, click and will stop and re-spool back up :bowdown:

    I'm sure it's screwing up the data on the platers as I've never been able to recover data after letting it sit next to it for a few minutes...
     
  7. OniMinion

    OniMinion ...recalls when this forum was actually about cars OT Supporter

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    Magnets can cause bad sectors. The cheaper the quality drive, the more likely. HD's have come a long way now. It used to be that a good bump to a tower to throw a sector off - not so much anymore. With SSHD's on the way, it's almost a thing of the past. This is a good point. Most speakers are magnetically sealed, and have been because of CRT TV's. They won't affect Plasma or LCD though. A bigger point, is a lot of HD manufactures magnetically seal their enclosures as well. I had the same question a few years back and did some research. It's a good one. I always aire on the side of caution, and keep electronics away from larger magnets (not the refrigerator variety.) Ask my good friend...
    ...His JL Audio subs (he has three 12w6) erased his HD last year. He put his laptop in his trunk for lunch, came back and the HD was toast. He was scared someone was gonna steal it in the neighborhood he was in... LOL
     
    Last edited: Nov 13, 2009
  8. deusexaethera

    deusexaethera OT Supporter

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    From outside the casing, the magnets have to be REALLY strong to cause any problems, and even then they'll only cause problems if the disk is spinning, because a spinning conductor next to a magnetic field...well...you know basic physics, right?

    Anyway, keep in mind that RIGHT NEXT to the disk platters, there is a reader arm that is moved back/forth by a linear motor consisting of a hinged coil of wire between two VERY strong magnets. However, because those magnets are backed with diamagnetic metal "keepers" and are in very close proximity to each other, the amount of magnetic field that extends far enough to intersect the disk platters is almost nothing -- most of the field is directed straight through the air gap between the magnets and through the middle of the keepers the magnets are attached to.
     
  9. OniMinion

    OniMinion ...recalls when this forum was actually about cars OT Supporter

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    This^ + VERY large magnets + Stupid user.

    /Thread
     
  10. OFI

    OFI New Member

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    :o boot = trunk
     
  11. OFI

    OFI New Member

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    Right that's it. Not going anywhere near it :rofl:

    Thanks for the responses :cool:
     

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