Suppose I have a hard disk with data I don't want to expose to a third party. The warranty period for that disk still lasts. Now the disk starts malfunctioning.

I can't use a disk wiping program on a malfunctioning disk - it just wouldn't work. If I run any destructive action on the disk - burn it, open and scratch it, smash it, whatever similar - the retailer will refuse to exchange the disk saying that the destructive actions void warranty.

How can I destroy sensitive data on a failed disk without voiding warranty?

  • What retailer nowadays even wants to see the original disk? – Teddy Oct 15 '09 at 12:17
  • @Teddy: Best Buy? – quack quixote Oct 15 '09 at 13:20
  • We are not located in the USA, the rules for exchange and business procedures differ a bit here. For example, retailers won't just let a drive go if we claim that it failed - replacement means literal replacement - we give the fialed disk to them, they give a new one to us. – sharptooth Oct 15 '09 at 14:29
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    Dell expects you to ship back drives in most cases and may charge you if the drive isn't returned. Most other companies (HP, Acer, etc) will have similar policies though ymmv as to enforcement and follow through. – pplrppl Oct 15 '09 at 22:00
  • With Dell and HP your can pay for not returning disks. It is called "KYHD" (keep your harddrive) or something similar. Often you can select this option while buying the server. – Nils Sep 21 '11 at 20:20

14 Answers 14


I would ask, what is the value of the data on the disk?

If it's more than the cost of a new disk, then my preference would be to destroy the faulty disk and buy a new one. You could spend a lot of time trying to get the disk working long enough that you could do a proper erase, but is it worth it? And do you know that it's definitely worked? What if there were some bad sectors that you weren't able to erase properly and still contain some data, even if damaged.

With the cost of hard drives today, if your data's valuable then buying a new disk is not a big expense.

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  • Agreed. If the data on the disk is sensitive, destroy the disk. Think of the cost to you if any non-destructive (degaussing) method doesn't actually work and your data is compromised. The only "sure" way is to destroy the disk. – Dave Drager Oct 15 '09 at 13:55
  • I agree with this as well. I don't send my server hard drives in for warranty repair / exchange any more. It kinda sucks having to lose a couple hundred bucks on each failure, but it's really not much in the grand scheme of things. – Boden Oct 15 '09 at 15:15
  • While I agree, it makes one wonder what the value of a warranty is? – Joel Coel Dec 11 '12 at 15:41

Just explain to your vendor that the disk failed but that you cannot return it due to sensitive data. Many vendors, especially vendors with business customers, will accept that without asking.

If they don't, offer a signed, written statement declaring that the disk failed. If that still doesn't satisfy them, write off the loss and consider buying the next disk from a vendor with a sensible warranty policy.

Dell e.g. even has this as an explicit option:

Dell: Keep Your Hard Drive

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    Note the "keep your hard drive" option costs you money up front/prior to them shipping you a replacement drive. That is not a free option and is sure isn't their policy. – pplrppl Oct 15 '09 at 22:02

You could ... degauss it. I mean, it's already broken ...

You just need to find a significantly large electromagnet.

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    +1 for use of a large electromagnet :D – ITGuy24 Oct 15 '09 at 12:32
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    I suspect that would count as a "destructive action that voids warranty". After degaussing, a harddisk typically no longer works (as it erases control information on the drive's surfaces). – sleske Oct 15 '09 at 12:45
  • How will the vendor know you've done it? – Nick Kavadias Oct 15 '09 at 12:51
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    You don't need an electromagnet, you just use your collection of voice-coil magnets that you've taken out of other dead hard drives. You do have a collection of those magnets don't you? They're powerful rare-earth magnets, and if you put a few of them together (or get a big one from an older hard drive), you can wipe the servo tracks from a hard drive w/out opening it up. – Ward - Reinstate Monica Oct 15 '09 at 13:39
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    Just talked with a data recovery expert - he told me that degaussing is not very effective in safely clearing disk. He recovered degaussed disks before. – Amir Uval Feb 16 '14 at 10:01

If the data is so sensitive, you can afford to buy another disk and scrap this one, otherwise look for a specialist in HDD data recovery and ask them what they can do about your problem, as they'll probably know how to handle your request.

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  • +1 for pointing this out - if your security concerns and policies are serious then the cost of the voided warranty is pretty minor, or at worst you should factor this in to your estimate of the costs of supporting your systems. This is no help after the fact but going forward you should budget for being able to deal with this scenario. – Helvick Oct 15 '09 at 18:08

I'm based in Norway, and we degauss failed drives using equipment from Ibas. Dell, HP and IBM all accept the destroyed media as return for warranty replacements.

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Many disk failures are attributed to the disk firmware predictive error checking flagging the disk as bad. Unless there is a head crash or physical problem the data is still accessible. You are correct to make the assumption that the disk might months later show up on ebay.

If this is a SATA disk, consider using the disk's firmware level secure wipe function. It's been included on all SATA disk firmware since 2001.


UCSD’s CMRR to the rescue The University of California at San Diego hosts the Center for Magnetic Recording Research. Dr. Gordon Hughes of CMRR helped develop the Secure Erase standard.

Download his Freeware Secure Erase Utility, read the ReadMe file and you’re good to go.

To use it you’ll need to know how to create a DOS boot disk - in XP you can do it with the “Format” option after you right-click the floppy icon in My Computer.

You may have to dink with the bios on a desktop PC to get it to work properly. Most motherboard manufacturers have blocked the function because of course it is dangerous. They typically do this by locking the drive access during post, you can get around this with the right bios settings and waiting to connect the SATA data cable until after post is completed.

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You could build your own electromagnet. Get an iron nail, wrap copper wire around it (the more wraps the better) and connect the ends to the positive and negative leads on your battery (9 volt, 12 volt, etc). However, again this method most likely won't work. Firstly, it's an unchanging current and secondly the strength of this magnetic field pales in comparison to the field emanating from the read-write head hovering microns above the platters surface.

To really erase a disk you will need a strong fluctuating field, slowly diminishing its intensity. You could probably achieve this by wrapping the drive itself in a few hundred turns of wire, and then connect that to an auto-transformer, plugged into AC power, and start it up at some high voltage and then run the voltage slowly down to zero. That would probably be enough to ensure saturation, and then complete elimination of data as you diminish the field and randomize the platters from inside to out.

That being said, with the relatively low cost of storage these days the simplest way of ensuring that your data is destroyed is to physically destroy the media storing the data. A good drill is cheaper and faster than the suggestions above. Which is more fun is a matter of opinion.

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If you have sensitive data on the disks then you probably want it encrypted anyway. Physical attacks on your infrastructure (thieves, police who raid your machine by mistake then lose the disk, simple human error) are potential risks to be considered. Then you can hand over the disks untouched and intact. Even more so if the disk is also part of a raid set as they don't get anything useful to even try brute force attacks (without having the whole set, which would be true for RMAs I hope).

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    Given enough time, any encryption key can be broken. An encrypted hard drive, even damaged, in the wrong hands, can result in leaked data. – Joel Coel Dec 11 '12 at 15:42
  • @JoelCoel: No, that's not true. If the drive is properly encrypted, a brute force attack is (phyically) impossible - see e.g. Amount of simple operations that is safely out of reach for all humanity?. Of course, there are a lot of mistakes you can make when encrypting things... – sleske Dec 3 '14 at 8:54

I have had failed disks respond when removed from the machine and placed into a external case.

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Was this disk the main disk? I have found that when a HDD goes I can usually pull stuff off of it if I put it in another machine as a slave drive and get what I can (or use a live CD). You might be able to run some sort of drive wipe this way. When the OS is running off a failing disk it's nearly impossible to do this.

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Another trick I've used in the past, if the failure was in the electronics, (not a head crash), and you have an identical drive, you may be able to swap the electronics board, and get it working.

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You could also try freezing the hdd. Other have had varying success with it, here one. The good news is that it won't do any physical damage to the drive that the retailer will be able to detect, so it shouldn't void your warranty. Just be sure to remember to put your drive in an Ziploc (or similarly airtight) bag to keep out any moisture.

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The safest way is to literally smash it with the hammer, open it and then scratch the internal disks with the screwdriver. That's what I do when getting rid of sensitive info.

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    I guess this will void warranty. – sharptooth Sep 21 '11 at 5:48

You could try running spinrite on the HDD to see if you can get it working again, at least enough to delete the data.

If they are swapping it out under warranty they're not going to run any undelete or data recovery program so any "data" you don't want to expose to a 3rd party will be safe enough being deleted. But you might be able to run Darik's Boot and Nuke if spinrite gets the drive working.

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  • This fails to take into consideration what becomes of the drive both in transit to the manufacturer, and after the manufacturer has decided that the drive is worthy of being replaced. Don't take this chance, degauss your drive! – eleven81 Oct 15 '09 at 18:45
  • Manufacturers often offer re-conditioned drives where they just replace the component that failed and put them back on the open market. I'm sure someone with enough effort could pull back whatever used to be on that drive before it was sent to the manufacturer. – Mark Henderson Oct 15 '09 at 23:19

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