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Cheap Bulk Eraser for Hard Disks? 166

Posted by Cliff
from the alternatives-to-smashing-platters dept.
cute-boy asks: "Recently I had to replace some hard disk drives from the same batch which had failed, while still under warranty. Because the drives were no longer recognized by the SCSI controller, it was not possible to erase the data on them. In view of the sensitivity of the data contained upon them, and the chance this was still forensically recoverable, our company decided to buy new drives rather than risk the disclosure of their contents by returning then to the supplier. How would you non-destructively (physically) destroy data on a hard disk without access to a bulk eraser? Obviously in this case it's a bit late to be thinking of using encryption."
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Cheap Bulk Eraser for Hard Disks?

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  • by daeg (828071) on Saturday September 09, 2006 @07:38PM (#16073455)
    Why are you against physical destruction? Let your IT department have a field trip to an abadoned parking lot with some sledge hammers.
    • Re: (Score:1, Insightful)

      by linkedlinked (1001508)
      I think the idea was that the poster would like to preserve the drives, and thus still qualify for possible returns (warranty or otherwise). The options are "Physically destroy (or retain ownership of)" and "secure wipe, return for $$$." Clearly, one is a more attractive solution, especially if the volume of disks in question is particularly large.
      • Re:Why no physical? (Score:5, Informative)

        by bhmit1 (2270) on Saturday September 09, 2006 @07:56PM (#16073557) Homepage
        A bulk eraser, aka degausser, will destroy not only the data, but also the factory written tracks. The end result is that the drive can never be used again. This may invalidate the warranty if the manufacturer doesn't offer the "send back the face plate" option. Not to mention, most of these degaussers cost 10 times that of a replacement drive according to a quick google search. Considering your line of work, make sure you pick drives from manufacturers that allow replacements without sending back the data.
        • by CastrTroy (595695)
          That's a great idea. I never knew that there existed manufacturers that didn't require you to send back the entire unit in order to obtain a refund. How do they protect against people taking off the faceplates, and replacing them with another sheet of metal, and sending back the original faceplate to basically get a free drive? I guess you'd have to do it in a clean room to stop dust from getting on the disk, but if you already had a cleanroom at your disposal, then what's to stop you.
          • I never knew that there existed manufacturers that didn't require you to send back the entire unit in order to obtain a refund.

            Actually, I don't send back anything except a sheet of paper that says the old drive died and I have destroyed it. It helps that I work for an organization [irs.gov] that buys 30-40K drives a year; we can negotiate deals like that. As for the possibility of using this situation for personal enrichment, no computer tech in this place is going to risk losing their job and jail time just to p

            • Re: (Score:3, Funny)

              by markhb (11721)
              Dude, you work for an organization that can cure acute constipation remotely, just by sending a letter. I would be very surprised if there were a deal you couldn't work out.
        • by edmudama (155475)
          This is true... the drive could be reconditioned in the factory, but most end users won't have the equipment to do so.

          I know drive companies have, in some cases, accepted photographs of the drive top stickers and serial numbers for warranty returns. The company signs a contract promising that these drives really are bad, and in exchange the drive vendor sends them a replacement. This works around the rules of many sensitive installations where no non-volatile storage can leave the premises without being c
      • by tsa (15680)
        I think with the prices of hard drives these days the amount of time you invest in wiping the data off the hard drive costs more than the drive itself. I wouldn't bother myself asking /. and wiping every drive, but use the sledge hammer.
      • by Tweekster (949766)
        For some reason the return for money idea just has "Disaster, written all over it"
    • Re: (Score:2, Redundant)

      by queenb**ch (446380)
      Your choices are:

      1) $2000 degausser
      2) $50 for a really nice sledge hammer from home depot (shock absorbing handle)

      Since they were willing to spring for replacment drives rather than risk data disclosure, I'd opt for the sledge hammer. You can buy a lot of hard drives for $1950.00.

      Consider it therapy for the geeks...

      2 cents,

      QueenB

      • by GMC-jimmy (243376)
        The cost comparison doesn't seem right here. It's not cost of erasure tool to cost of replacment drive unit.. it's cost of erasure tool to data integrity damage.

        If the data in question got out and it will cost more than $2000 in damages, then buy the degausser as a one-time-cost preventive measure and use it.
      • If you open up the drives and flip the platters the low level MFM encoding used to store the data magnetically will be reversed. Anybody who tries to read the drive will get garbage (or maybe a satanic message!).


        Should only take you about ten minutes per drive to do this. All you need is one of those special screwdrivers.


        PS: Do it in a recently vacuumed room - if dust/hairs get in the drive it can be detrimental.

    • Re: (Score:3, Insightful)

      by Wwolmack (731212)
      Breaking hard drive platters is not easy, and given a significant level of paranoia, physically snapping the platters in half may not be enough.
      Degaussing the drives may not be thorough enough, given various anecdotes about the ability to recover data off almost any drive using fancy super-expensive equipment.

      Unless you've got IBM Deathstar 75GXP's (and if you do, well your data is already as good as gone), your platters are probably metal. Even if you have Deathstars, their platters are glass and are susce
      • Based on personal experience, heating a hard drive platter with a blowtorch for 30 seconds and then plunging it into ice water is a _very_ easy (and explosively effective) method of breaking a hard drive platter...
  • Open the hard drive (get some Torx T-7 through T-9 bits first, you'll probably need them), pull the platters, and sand them.
  • The poster seems to indicate that the drive has failed and it's impossible to write to it via the normal scsi interface. At that point, the only way to render the data unrecoverable is the physically destroy the platters.

    I like taking the drives apart for the magnets, then using heat on the platters...
  • by voice_of_all_reason (926702) on Saturday September 09, 2006 @07:43PM (#16073487)
    ...and they can be quite fun... I guess your only option is to open up the new drives, swap the platters, and erase the data that way. Then swap the platters again if you wish so that they're (technically) new again.

    Never tried it myself, though everyone on the intrawebs largely agrees that there are legions of the mighty dust army waiting breathlessly for you to crack open the drive so that they can invade it. There is apparently no invention of man capable of withstanding their attack, meaning a high possibility that if you perform this operation and then plug the drive back in, a single dust atom will be all that is needed to whir around frantically in the formerly pristine environment, loosing the veritable fires of Hades on your poor machine until it erupts in a wild, flaming mess, sending shards of platter in all directions to seek the soft flesh of babes and women.

    So yeah, they don't recommend doing that.
    • I guess your only option is to open up the new drives, swap the platters, and erase the data that way. Then swap the platters again if you wish so that they're (technically) new again.

      Won't work. At least, not in a drive with more than one platter. Not reliably, anyway. If the platters are not aligned with each other in the exact same position they were in the original drive, it probably won't be able to read the firmware from the drive's track zero, so it won't identify itself to the BIOS properly, or

    • On the other hand, I knew an old hardware hacker running a small computer shop in rural NC... customers would bring in failed drives, if he could determine the failure was on the controller, he would find a spare drive with the same model number and swap out the controllers - revived the drive with data intact.

      Not sure if it's possible / easy to do that with these particular drives, but it's worth looking into...
      • by Scoth (879800)
        I bought a lot of 10 identical 40 gig laptop drives from an eBay seller for some teeny pittance (I want to say something like $10 shipped) that were explicitly sold as non-working. Of the bunch, most of them didn't do a thing. However, there were 2 that had some broken pins, and a few that read fine but had massive data errors. I had no trouble swapping the controller boards from the ones with broken pins from one of the data error ones and ended up with 2 good 40 gig drives for $10. Wasn't too shabby I tho
    • to seek the soft flesh of babes and women.


      This sounds so redundant...
  • by GarrettZilla (103173) on Saturday September 09, 2006 @07:46PM (#16073505)
    • Yes that's exactly what I'm going to do with my sensitive data. I'll give the working drives to someone who promises destroy them for me. Plus I get to pay for it. :rollseyes:
  • by Fallen Kell (165468) on Saturday September 09, 2006 @07:47PM (#16073513)
    Well, most all hardware manufacturers will offer you replacements even without sending back the complete drive. You need to contact them by phone and setup the special RMA. For instance, we can't send back any of our disks if they fail due to the data. We can only send back non-electrical and non-memory containing parts. A lot of times we simply send back the cover plate to the disks. I know for a fact that Seagate and Western Digital will take back disks like this if you explain the situation.

    Also depending on who your vendors are, you can usually upgrade your service so that you do not need to send back failed disks. Dell for instance has this as part of one of there higher level support contracts.

  • Top cover? (Score:2, Informative)

    by Anonymous Coward
    I've heard that most HD manufacturers understand this common problem, and will allow you to remove and return only the top cover (with the complete model/serial number sticker still entact) of each failed drive as proof that it was destroyed. You should ask about this when requesting an RMA number for your batch of dead drives.
  • I've heard somewhere (Score:3, Informative)

    by vadim_t (324782) on Saturday September 09, 2006 @07:52PM (#16073535) Homepage
    That some companies have a deal with the hard disk manufacturer that they'll ship only the drive's cover when it fails, and destroy the rest. Not 100% sure if this is possible, but if your reason for wanting to wipe the drives is getting a warranty replacement, you might want to consider that.

    Otherwise, use thermite, and lots of it. It's cheap and fun.
  • It is hard for me to believe that no one posting has yet understood the question. The issue is that the querent has failed piece of hardware, under warranty, but doesn't want to return it for replacement fear that the data could be recovered by a highly motivated party.

    The answer seems clear. Even if you hard a piece of equipment to erase a drive's contents, you would not be able to verify that the erasure has occurred without the drive functioning in the first place. Therefore, there is unlikely to be
    • Highly recognizable keyword(s) + question mark = highly qualified answers from first posters who never made it past the first sentence.
    • by SpacePunk (17960)
      I find it hard to believe that your company has such information that you'd think that people would go out of their way to recover the drives in order to damage it or steal information. I think the corporate ego there is probably running rampant.
  • Magnets! They might bend the heads and scratch the surface, making if that is what you cann 'non-destructive', but it always works. And no refrigerator magnets, obviously.
    • Re:Magnet! (Score:4, Informative)

      by Nutria (679911) on Saturday September 09, 2006 @09:18PM (#16073887)
      Magnets! They might bend the heads and scratch the surface, making if that is what you cann 'non-destructive', but it always works.

      The military doesn't think so.

      There's
      • Software wiping (MilStd 5220.22-M)
      • Degaussing (MilStd 5200 28-M)
      • Destroying the platters. "destroyed by melting, incineration, crushing, or shredding."
      This is more difficult than you think.

      http://cc.uoregon.edu/cnews/summer2005/purge.htm [uoregon.edu]
      For example, see the March 2004 Network World article "Inside the DoD's crime lab," which recounts how the Department of Defense computer forensics lab has been able to successfully recover hard drives that have been "thrown off of balconies and even shot with AK-47s, as in one recent battlefield case."
      So, hitting with a sledghammer doesn't seem very effctive.

      A power drill and wire cup brush (http://shop.com.edgesuite.net/ccimg.shop.com/2300 00/230300/230375/products/lg_33486043.jpg [edgesuite.net]) would definitely work, as would various acids (which have hazards of their own).
      • The military doesn't think so.

        There's
        ...
        Degaussing (MilStd 5200 28-M)


        I thought degaussing was accomplished via exposure to an oscillating magnetic field.

        Cool links. [blogspot.com]
      • by jabuzz (182671)
        Most modern platters seem to be coated with some protective material (plastic?). I tried to destroy a range of platters from inside some broken hard disks of unknown origin at work. They where placed in a fume cupboard, and some concentrated HCl pored on them and left for 24 hours. Some older ones (MFM era drives) where well gone, but the newer ones (think 80MB IDE) where still intact!

        Now for sensitive data, I remove the platters from the drives, collect them up and once a year on the 5th of November I put
        • by Nutria (679911)
          They where placed in a fume cupboard, and some concentrated HCl pored on them and left for 24 hours. Some older ones (MFM era drives) where well gone, but the newer ones (think 80MB IDE) where still intact!

          Very interesting. Probably glass/ceramic platters.

      • Don't forget that if you get a feromagnetic piece of metal above it's critical temperature, it's not freomagnetic anymore and everything is gone. I never understand why this isn't the most popular method of getting rid of these things, a nice big kiln set to some high temp cone out to do it. The bonfire method suggested elsewhere in this thread is safe because of this too. So long as you don't breathe near the fire.
  • Had a similar problem where 1 of 2 hard drives (same model) failed. I switched the logic board out of the good one, used it to replace the dead one, reformatted/overwrote to my heart's content, then switched the logic board back to my good drive.
    • Data recovery companies can fix the logic boards too. I would imagine that the poster would be concerned about data recovery companies seeing the data also though.

      Another idea is to cook the drives. Heating a drive in an oven should give the data a good scramble. I'm guessing it is probably better than a degausser considering some of the comments here.
  • As emphasized in other comments the only way to truly erase a hard drive is to destroy it.

    My favorite method involves and magnetic induction burner or hotplate. The benefit of this is it will destroy the data but leave no external trace.
  • IIRC, the magnetic coercivity of modern hard disk media is sufficiently high that the only sure method of data destruction is physical destruction of the platters.

    Sledgehammer in the parking lot on the platters (removed from the drive, if possible) should do nicely for any application short of national security secrets - just be sure to wear safety goggles.

    -Isaac

    • by technotot (899952)
      agreed. unless you have access to the NSA building or an electromagnet, id say (unfortinately)[sic] isaac is right. try to have some fun with it. go hang up some signs and offer 5 bucks to the first person to get it open, and the guy who shatters the platters. -Justin
  • by Anonymous Coward
    I just modded down 4 people in this article, which out of the couple years I've been getting mod points probably doubles the number of posts I've modded down.

    THE POSTER ISN'T ASKING FOR METHODS TO DESTROY THE PHYSICAL DISK -- in fact, he specifically says that he does NOT want such methods. What he wants is ways to destroy the DATA without destroying the DISK so that he can return it to the vendor for warranty replacement.

    Thus everyone saying "destroy it with thermite", "find someone with a tire shredder",
    • to the pertinent question.

      There is probably no such thing as a cheap and effective bulk eraser. We have an agreement with Maxtor (now Seagate) that allows us to send in the chassis for a replacement, minus the platters. The replacement contract is expensive, though, but we need it since we have a LOT of banking data.
    • by CrazyJim1 (809850)
      I just modded down 4 people in this article

      And because you posted in this article, all your moderation is erased like their harddrives will.
      • And because you posted in this article, all your moderation is erased like their harddrives will.

        Yes, of course.

        Does nobody pay attention to ANYTHING anymore?

    • Most regular Slashdot readers know that the askers in Ask Slashdot articles rarely ask the correct question.
  • by Bombcar (16057) <racbmob@@@bombcar...com> on Saturday September 09, 2006 @08:11PM (#16073610) Homepage Journal
    Maxtor, Western Digital, and Hitachi all replaced drives that we'd sold into sensitive environments with little fuss. Hitachi needed a signed form faxed back, Maxtor & Western Digital needed the top cover of the drive.
  • If you do decide to go down the destructive disposal route you could do what the Aussie department of defence does. 1. Get a big grinding wheel 2. Push harddrives against grinding wheel and collect dust 3. Mix dust with concrete 4. Build a building with said concrete
  • The most painful way, but only sure way to accomplish this is to disassemble the drive and melt the platters. If they are really old drives, then waving the disassembled platters under a wand-based degausser usually works. This stuff is all measured in oersteds. The recording head has to overcome the coercivity of the magnetic media in order to record a reliable signal. Coercivity is the strength of magnetic field (measured in, you guessed it, oersteds) required to alter the alignment of the particles o

  • Degausing Table. (Score:1, Interesting)

    by Anonymous Coward
    When I wored at a knife factory we had a degausing table.
    It was THE COOLEST THING. You would place anything with iron and/or magnets on it, turn it on (don't wear a watch) and all magnetism is gone with in about 2 feet.
  • And explain your concerns. Some manufacturers have a policy where you only return part of a drive (usually the cover) if you don't want your sensitive data to be transported.

    Once you get the replacement drives, take them to the range and fill them with bullet holes. A 2 3/4" 12 gauge slug should take out a quarter of the drive at a time. Or fill with 9mm holes - when hit, the platter around the entry hole gets pulled out.
    A .22 from a rifle will work as well, but you'll need to put a dozen rounds through it.
    • by loraksus (171574)
      or rather take the *dead* drives to the range ;)
    • by TheLink (130905)
      Shooting won't work well. Melting definitely works.

      Use a blowtorch.

      Lava is a good place to dump em, but could be a bit inconvenient.
      • Lava is a good place to dump em, but could be a bit inconvenient.

        BOFHs around the world rejoice that they now have a good excuse for travel to Hawaii...
  • Well, the statement "it was not possible to erase the data on them" directly contradicts the possibility of an answer the question of how to "non-destructively (physically) destroy data on a hard disk without access to a bulk eraser", unless of course, your current limitations include the magical exception of having access to some really fun electronics equipment.

    Then again, I'm still wondering WTF the term "bulk eraser" is supposed to mean.

    A useful starting point would be reading Secure Deletion of Data fr [usenix.org]
  • First, I don't think that bulk-erasing counts as non-destructive today. Not all drives can do servo writing without additional equipment.

    Second, I don't think you can get bulk erasers that work for modern harddrives. The magnetic fiel strenght may just be too large.

    Advice: Do physical destruction and live with the financial loss. Acting first and thinking later has a price. Please pay it.
    • by Detritus (11846)
      First, I don't think that bulk-erasing counts as non-destructive today. Not all drives can do servo writing without additional equipment.

      I'm not aware of any modern hard drive that will survive erasure of the embedded servo data.

      Second, I don't think you can get bulk erasers that work for modern harddrives. The magnetic fiel strenght may just be too large.

      You can, they just wont be cheap or small. See the NSA Degausser Evaluated Products List [nsa.gov] (PDF).

  • 1. If the drive is no longer recognized by the controller then the circuitry on the board has been damaged. Replace the board from an identical drive and you may be able to access it again.

    2. If your data is so sensitive that you can't risk sending it back then that risk is far more than the cost of the drive. Physically destroy it and buy some other brand to replace it.

    3. Its doubtful that degaussers (as suggested elsewhere in the responses) would work. The platters are encases in relatively think metal wh
  • If you're a big enough customer, or the vendor is understanding, perhaps you can arrange for them to inspect the drives under your supervision and confirm that they are no good. Then take them, accompanied by the vendor's representative if they want to be sure you destroy them, and drop them into the vat at your local steel mill, or whatever less dramatic method of physical destruction works for you.

  • by AJWM (19027) on Saturday September 09, 2006 @10:00PM (#16074047) Homepage
    the drives were no longer recognized by the SCSI controller,

    A problem with the SCSI controller, or with the drive's on-board electronics?

    If the former, just replace the controller. Check this by moving the drives to a box with a working controller.

    If the problem is the on-board drive electronics, then using a working drive of the exact same make and model, carefully undo the 3 or 4 screws holding the circuit board to the drive and swap the board from the good drive with the board from the bad drive. If this was the problem you should now be able to access the data on the old drive.

    I've done this with a Seagate Barracuda that had its electronics fried because of a catastrophic power supply failure (detonated one of the chips and vaporized a couple of circuit traces). Swapping the board from an identical drive (I had a bunch around) let me recover the data. Not knowing the condition of any circuitry within the drive itself, I retired the drive after copying off the data. I would have erased it too but I was planning on disassembling it anyway.

    (NB - even the same make an model number doesn't guarantee interchangable parts -- I had a similar problem with a Western Digital 80GB drive that I didn't happen to have a duplicate of, although that model was still on the market. Alas there's another 4-character code after the model number (ie, the "real" model number, except you need to see the faceplate to find it out) and in the year or so since buying the first one, there were enough minor changes that the circuit boards weren't interchangeable.)
    • A problem with the SCSI controller, or with the drive's on-board electronics?

      If the former, just replace the controller. Check this by moving the drives to a box with a working controller.



      Don't overlook the possibility an employee may have lifted the terminator. I've seen where this is overlooked when drives stop working in a SCSI environment.
      • by AJWM (19027)
        Yeah. I almost mentioned that (and just checking termination in general) but figured "nah, that's so obvious he has to have checked it first". But you have a point, some things are so obvious that they are overlooked.

        ("Did you check that it was plugged in?" "Don't be silly, of course I ch... Oh, oops.")
  • This won't help so much this time, but if the disks were encrypted with a strong password - you only have to enter it when the system is booted, and for a server this shouldn't be too often - then you could send back the disc without the manufacturer being able to read the data.
  • One magazine load (10 rounds) about $2. One destroyed disk drive, priceless.

    Fun too. They bounce around pretty nicely.

    Of course, if you want to send it for warranty exchange, the manufacturer probably wouldn't appreciate yoru marksmanship. But if the alternative is to keep them forever so no one else can try to recover the data, I'd say go for the AR-15.

    Or M-1 Garand. Or any other reasonable facsimile.
    • That might not be the best tool for the job. Supporting it for multiple shots is going to be difficult, and when you hit it, it's just going to fall over. You might consider one of these [benelliusa.com] which would complement the hard drive's convenient size for launching out of a sporting clay thrower.

      Anybody know the appropriate sized shot for a hard drive?
      • I had my disk drive laid against a hillside across from my front door, 75% slope or so ... it sometimes slid around, sometimes jumped a few feet in the air, and being only 100 feet away, it was easy to go pick it up if it moved too far.
  • 50-100oz magnet and sit it on top of the hard disk. Like the kind you find on the back of PA woofers. It's worked for me :)
  • "Recently I had to replace some hard disk drives from the same batch which had failed, while still under warranty. Because the drives were no longer recognized by the SCSI controller, it was not possible to erase the data on them. In view of the sensitivity of the data contained upon them, and the chance this was still forensically recoverable, our company decided to buy new drives rather than risk the disclosure of their contents by returning then to the supplier. How would you non-destructively (physical
  • We've seen lots of stuff put it there, how about you try it with a hard drive? :-D
    • Well, I have been known to eat some pretty indigestible meals in my time, but I think I would draw the line here. Otoh, I'll concede data recovery would be an unusual challenge after you had done this.
  • Sad to say, but if you can't run the drive to erase the data, you MUST destroy the platters. Even degaussing them is not reliable -- how will you KNOW the degauss worked? Unless you want to keep a spare drive of each model around with an open top so you can swap in and reformat platters from dead drives (way too much trouble), you're stuck with physical destruction.

    So, in keeping the military standards for such things, I suggest you find a way to render the platters unspinnable without creating too mush haz
  • You may actually be able to do the job with common office or household equipment. If you work at a hospital or clinic, for example, try running them through the MRI. Not only will the data not be forensically recoverable, but the disk should be sufficiently bent so as to discourage any attempt regardless. Also works well with floppy disks, VHS tapes, and metalheads.
  • Many years ago, when I was working as a tool of the military-industrial complex, we had a computer lab that was used for classified applications, and when we had dead disk drives (RM05 removable packs) or later when we decommissioned the lab, we had to wipe the disks.
    • In theory we could have used NSA-approved software, but I don't think there was any for that machine and we'd have had to prove that it could handle things like mapped-out bad sectors and such.
    • We could have used an NSA-approved Big Magnet,
  • The company I work for contracted with our offsite media vault vendor. They incinerated a few thousand backup tapes we didn't need anymore. Bonded and insured... and they let a rep from our company witness it.
  • If the data is life-or-death stuff incineration is the only way to go. In the army we used white phosphorus grenades for expedient destruction. You could probably get a civilian pyro expert to do it with thermite.

    If the sensitivity has a fixed (and reasonably short) duration secure storage may be your best bet. Could be as simple as, say, putting it in a cabinet in the server room for a year, by which time the patent application will be filed and you can just tip the drive.

    The most likely scenario is tha
  • by MooseTick (895855) on Tuesday September 12, 2006 @09:20AM (#16088281) Homepage
    I recently got rid of some very OLD equipment. I had some old hard drive that predated me by 15 years. They were huge and I had no idea what was on them. They weren't IDE or MFM. They came from the day that hard drives required an external controller card. Since I needed to wipe anything that left the building I didn't have many options. I did what my predecessor and his predecessor had done.

    I left the drives sitting in a cabinet where they had sat for the last 2+ decades.

    Since you don't need to send the drives back to the manufacturter and you just need to be sure no one else can get the data, why don't you just sit on the drives? If they sit there for 10-20 years then even if the data were to get out in the wild it would likely be 100% useless anyway.

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