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A Walk Through the Hard Drive Recovery Process

Posted by kdawson on from the it's-dead-jim dept.

Fields writes "It's well known that failed hard drives can be recovered, but few people actually use a recovery service because they're expensive and not always successful. Even fewer people ever get any insights into the process, as recovery companies are secretive about their methods and rarely reveal any more information that is necessary for billing. Geek.com has an article walking through a drive recovery handled by DriveSavers. The recovery team did not give away many secrets, but they did reveal a number of insights into the process. From the article, "'[M]y drive failed in about every way you can imagine. It had electro-mechanical failure resulting in severe media damage. Seagate considered it dead, but I didn't give up. It's actually pretty amazing that they were able to recover nearly all of the data. Of course, they had to do some rebuilding, but that's what you expect when you send it to the ER for hard drives.'" Be sure to visit the Museum of Disk-asters, too.

27 of 238 comments (clear)

  1. Re:Their secret revealed... by iMaple · · Score: 5, Interesting

    That's actually not to far away from a working solution. You can normally make a failing/failed harddisk work for around 5 minutes by freezing it and then immediately using it. Don't try to boot off it, just connect it as an external drive and you can probably get that code you were working on before the drive failed. Its worked for me all 3 times I've tried.

  2. This may be a dumb question... by TomRK1089 · · Score: 2, Interesting

    ...but are flash drives prone to the same sort of catastrophic failures disc drives are? And are the same recovery techniques workable with both? My gut tells me it's not nearly that simple.

    1. Re:This may be a dumb question... by Constantine+XVI · · Score: 3, Interesting

      And likewise, if you have data you need to get rid of, how easy/hard (compared to magnetic HDDs) is it to permanently blast data off a flash drive if you don't want the data found?

      --
      "I think an etch-a-sketch with an ethernet port would beat IE7 in web standards compliance."
    2. Re:This may be a dumb question... by piojo · · Score: 2, Interesting

      I accidentally dropped a flash drive in some espresso, and held it under the sink to rinse it out. After I dried it, it continued to work without loss of data. (I believe the drive did have water inside it.) Another time, my dad lost a flash drive. We discovered it that spring when the snow it was under melted. It worked fine after it dried (though I don't remember whether the data was still there).

      --
      A cat can't teach a dog to bark.
    3. Re:This may be a dumb question... by ajlitt · · Score: 3, Interesting

      Apparently not. The flash array is in the middle of a silicon die and protected with a layer of oxide and epoxy. The pins that come out of the chip packages go directly to some control circuitry and not the flash cells themselves. The flash cells are isolated unless the control circuitry actively tries to read them. So if you were to short all of the pins on the flash chip with the power off the data will still be intact.

      If you do put your flash drive through the washer / pool / toilet you should try to soak it in distilled (not deionized or spring) water for a while and then let it dry on a windowsill for a few days. As long as you don't plug it in until it dries it should work just like new. This is the same process used during manufacture of most PC boards with water soluble flux, so it's likely that your drive has already been dunked anyway.

    4. Re:This may be a dumb question... by camperslo · · Score: 4, Interesting

      The same recovery techniques can be used, and they need not be expensive.

      Not really. Software tools such as the one you mentioned, Magic Rescue, are for dealing with deleted files or corrupt file systems. That applies to both flash and magnetic drives.
      But for it to work on a magnetic drive, the drive pretty much has to be functional electrically and mechanically. Most drives like that would work after reformatting.
      For that software to work, the interface to the computer has to work, the spindle servo has to work, the head positioning system has to work, the heads have to be okay and have a working connection, and at least the read electronics has to work. A drive isn't really very dead if software can control it and read from it.

      A failure of some part of the drive hardware is likely to require repair or substitution of what's broken. I was disappointed that the article provided almost NO useful details on that.

      If the electronics has failed, substituting the circuit board from another drive of the same type seems like one thing that would be relatively easy.
      Those in the know should easily be able to tell if a head or connecting cable has become open-circuited. I suspect that cracked copper in the head flex cable is a fairly common problem. It is likely the as it first fails, a connection is lost more towards one end or the other of head travel. If one can run the electronics in a sort of diagnostic mode (to avoid aborting on errors), I suspect that a bit for bit copy can be attempted by physical location. That's likely what they're talking about when they mention making an image to recover from.

      If the heads/cables are trashed and not easily repaired in place, swapping the platters into another drive (after removing any debris) is one of the more extreme measures.

      There are probably alternate test-jig type fixtures available to substitute for normal drive electronics. I wouldn't be surprised if the most extreme tools allowed varying read-head preamp parameters and finely adjusting head positioning parameters.

      It's kind of sad that so much information is unavailable to most of us. With full schematics, details of drive firmware etc a skilled technician can do component level repairs. People used to laugh at tv repairmen when sets came along where they'd just swap individual circuit boards instead of finding the bad component. But that's the sort of thing we now see most of the time with our computers and consumer electronics, if they get "fixed" at all. Most of the so called repair people know very little about electronics. It's understandable that the low replacement cost of much electronics has made labor-intensive repairs cost prohibitive, but I'd still like to see schematics available for everything.

      It's sad that we've not only lost the majority of manufacturing jobs, but much of the service side too as a result of the "if it breaks buy a new one" way of doing things.

  3. Re:That's not an article, it's a long ad :( by Anonymous Coward · · Score: 4, Interesting

    Also the change of narration from "my brother in-law's drive" to "my drive" is a give away. The lazy author of the ad couldn't even bother to keep the details/made-up-story straight.

  4. Re:Hmmm. by somersault · · Score: 2, Interesting

    Note: I am now working there full time (while I was part time a couple of engineers were mostly responsible for IT support and I was doing coding, but now I basically take care of everything - one of the general office workers thankfully takes care of a lot of the easier IT support stuff while I *coughwastetimeon/.* code), and as well as the tape backup, I decided to hook up an external SATA HD on the fileserver that works as an extra backup each night, and makes recoveries a bit quicker than using the last tape if someone comes to me the same day that they lost their file, as well as meaning we have something quick and dirty in place to connect to another server if the fileserver server develops any major issues. A properly scheduled and maintained backup system is truly a thing of beauty :)

    --
    which is totally what she said
  5. Re:Hmmm. by Sanat · · Score: 4, Interesting

    That is a good point about not listing everything that requires backing up.

    I was on a customer's site one day in Detroit showing a new engineer about installing a mini-computer from the company we were working for at the time.

    On another mini-computer located about 50 feet away a customer did a sector by sector backup to another disk and in the process copied the wrong way and lost all of their information that represented two years work.

    He immediately panicked and looked around to see who he could blame the error on and decided to blame us... it was really pathetic because the other workers there knew he did it but he could not bring himself to admit it.

    We finished the installation and left so I never did here what happened to him.

    He was a doctor that specialized in bone deterioration and apparently the data could not be reproduced or re-keyed for some reason.

    --
    And in the end, the love you take is equal to the love you make
  6. Re:Their secret revealed... by mikael · · Score: 4, Interesting

    That worked for me - I recovered an entire hard disk drive (Hitachi Travelstar) using the freeze and sudden twist method. Basically you freeze the hard disk drive to get whatever it is that sticks, to become brittle, and then give the drive a sudden twist to free the platters. This will last as long as the drive motor keeps running. Blogosphere theory is that it is the oil from the platter bearings that leaks and hardens.

    --
    Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
  7. Any *REAL* information out there? by ziah · · Score: 2, Interesting

    Are there any *REAL* guides out there that will show you how it's done through purchasing hardware from a store? It'd be nice to be able to do this all yourself if you have the right tools...

    1. Re:Any *REAL* information out there? by postbigbang · · Score: 2, Interesting

      We recovered numerous ones, especially in the easy old days.

      A few of our techniques:

      -Slam an ST-225 onto a table to get the heads off the drive, a condition known as 'striction'
      -Recovered a Novell-formatted drive by using an identical one's logic board, and a few well-placed jumps to its table
      -Used a sector editor to hand copy one copy of a FAT to the primary table
      -Figured out, then wrote a master boot record from one drive to another (in SVR4) doing the recalc on the drive geometry
      -Found a MBR virus, including epithet, on an early laptop drive; we x-d it out and the machine finally booted to the point where we got to the place where we could write a new partition table.

      These days, we just backup things furiously. Bad hard drive? Take out back to the trash. Restore. Repeat.

      --
      ---- Teach Peace. It's Cheaper Than War.
    2. Re:Any *REAL* information out there? by FlyingGuy · · Score: 2, Interesting

      Unless there is physical damage to the platters, which is pretty much obvious, then you do not have to do much if it is either the spindle motor / control logic / bearing assembly or the Head Actuator / or heads themselves.

      The days of having a platter dedicated to a servo track are gone, but the drive will orient itself and figure out where things are located. If you can get the platters from an old drive, into the new drive, in the correct stacking order, then on spin up, the heads should un-park, and the drive should be just as it was, and run for however long the chassis will last.

      If The heads crashed into the platter(s), its another bowl of rice. At that point things get a little sticky. The new chassis will attempt to orient itself on the platter(s) but if it cannot find its synch point, then all bets are off, and you need a very special bench setup, where you can give direct commands to the drive logic, and then view the results, because you will have to re-establish synch, and that is not easy.

      --
      Hey KID! Yeah you, get the fuck off my lawn!
  8. What is a good DIY success rate? by thogard · · Score: 5, Interesting

    I've done a few platter swaps and have had good luck if I can find the right donor drive. So far I've gotten data off most of the disks I've tried but sometimes the recovery rate can be as low as 25%.

    I recommend that people buy drives in pairs. That way you have a good drive to use as parts once the data has been moved off to a newer drive.
    I do repairs in my house so there isn't a clean room in sight.
    If the board is fried, a board swap tends to do the trick but the bad sectors are stored on the board so the mapping will result in some bad data.
    I start with the hard drive in the freezer (using a external firewire case) trick first. That tends to get noisy bearings about 3 hours which is enough to copy data over.
    If that doesn't work, I do a platter swap. I disassemble the drive and I've found that normal printer paper works great for lifting out the platters with out scratching them. Just make sure you put them in the donor drive in the same order and don't flip them. Once the platters are in, it appears that the drives have a few days to live before they stop working. With head crashes, you might want to consider only putting the good platters in. I have yet to find a good cleaning solution so with crashes you have a very limited amount of time but head crashes seem to be rare these days.

    Once you can read the disk, use DD to copy the data to a new disk. Don't try to mount it to look for a specific file unless you only need one file and mount it read only. For data file recovery, I use a mac program Data Rescue by Prosoft which is good except it sometimes is too good and pulls out the internals like pictures out of flash and office docs.

    If your going to do this at home, take apart a few older disks first. Keep in mind they designed these things to be assembled quickly so there is a way to retract the heads completely off the platter so hunt around for it. There are some people who use vacuum cleaners to try to remove dust and others will use a shower to steam up a bathroom and wait until the steam clears with the hope of taking the dust away. I just open the drives on my computer desk.

  9. Where's the beef? by hurfy · · Score: 3, Interesting

    A little light on content as others mentioned :(

    Nothing as interesting as the crash on our old mini-computer ages ago either. One of those 12" drives with 4-5 platters had a head crash and repurposed itself into a metal lathe quick nicely one weekend. At least it didnt burn down the building but it left several pounds of aluminum confetti all over the computer room after it blew out the filters on the drive. It seems you just can't filter air by the pound :( One head crashes and causes a chain reaction after the aluminum shavings clog the filters or interfer with the others. Luckily the software forced you to backup on the removeable platter each day. Only loss was a couple software mods (that the writer had a copy of) cause the system platter backup was kinda old, had to added back in.

    Needless to say, that had a zero chance of recovery. Only time a insanely overpriced maintainence agreement ever paid off...Drive was almost $20k to replace plus cleanup and setup on 200lb drive.

    Only other one that might have required a recovery service turned out to be electronic issue only and i sacificed a matching computer for the HD circuit board to repair the 'server' from a remote warehouse. Only some memos and spreadsheets and stuff and not worth the huge quote for recovery so i got to try it and fixed it the next day :)

    PS. always found it interesting the the edge speed was the same as current drives at around 105mph. The head hit a platter going between 50 and 105 mph.

  10. Re:Their secret revealed... by Crispy+Critters · · Score: 2, Interesting

    I couldn't get freezing to work on my dead drive. The trick that worked was: Let sit on the desk for two months and then try it again. It still made noise, but it worked long enough to find and retrieve the files that weren't backed up.

  11. Advertisement warning... by Anonymous Coward · · Score: 1, Interesting

    So in exchange for clicking the link and getting a full page video ad before getting to the article, I learned some amazing things about hard drive recovery like...

    1) First they take it into an ultra-cool clean room.
    2) They do something to it. Must be ultra cool.
    3) Recovered for $1900!!!

    I'm sure /. did a good job at helping him recover all 1900 of those dollars spent...

    For everyone else, don't bother with the link, my summary really is all there is to the article.

  12. Let's review. by dmarcov · · Score: 3, Interesting

    It's well known that failed hard drives can be recovered, but few people actually use a recovery service because they're expensive and not always successful

    Yep. The article helpfully points out the $1500 charge for a medium sized hard drive. It might have been more interesting if the article demonstrated a time when it wasn't successful.

    Even fewer people ever get any insights into the process, as recovery companies are secretive about their methods and rarely reveal any more information that is necessary for billing.

    So, just like this article? Got it. Something involving putting old platters into new drives by people wearing bio-hazard suits.

    The recovery team did not give away many secrets, but they did reveal a number of insights into the process.

    Wowsers. You can say that again, but insights? I defy anyone to name any insight that wasn't in their last press release ... much like this article.

    [M]y drive failed in about every way you can imagine. It had electro-mechanical failure resulting in severe media damage.

    Doesn't "elctro-mechanical failure" describe anything that could be wrong with a device that is .. err .. mechanical and electrical? You mean the reciprocator was caught in the optical refraction? Now that's worth $1500.

    It's a good thing space on the interwebs is free. Someone should run this past the kids that edit airline magazines.

  13. Nice Theory But... by Gates82 · · Score: 5, Interesting

    Blogosphere theory is that it is the oil from the platter bearings that leaks and hardens.

    That is a nice theory but there is no oil in the bearings of a Hitachi (formerly IBM) drive. They ride on an air bearing. I have heard of faulty temperature sensors being reset through the freezing method, but whatever the reason I have seen the freezing method suggested by several sources. For me I believe that it has to do with moving the drive. Shorts or binds will often be resolved by moving the drive around.

    When I worked for IBM I did a fair share of data recovery. My favorite drive that I saved was a laptop drive with a stiction problem. It would get caught during spin-up. I put my ear to the drive and would listen to it and kept rebooting and shaking the drive until it finally got past the rough spot. Recovered all the engineers data who was extremely happy he didn't have to waste $500 bucks with Ontrack.

    --
    So who is hotter? Ali or Ali's Sister?

    1. Re:Nice Theory But... by ajlitt · · Score: 2, Interesting

      My favorite disk to recover was a Quantum SCSI drive from an old Performa. That model frequently developed congealed oil in the armature bearings. The disk would run for a bit then stop since the heads wouldn't be able to move to a position to receive the servo pulse.

      The best way to get the drive going again was to power it up and about 1/2 second later give the edge opposite the connectors a light whack with a mallet. That would unstick the heads long enough to leave park and warm up.

    2. Re:Nice Theory But... by milsoRgen · · Score: 2, Interesting

      there is no oil in the bearings of a Hitachi (formerly IBM) drive. They ride on an air bearing. As do all other hard drives.
      --
      I'm sick of following my dreams. I'm just going to ask where they're goin' and hook up with 'em later.
    3. Re:Nice Theory But... by iocat · · Score: 3, Interesting

      I had a Mac IIcx with the same issues. When the drive (a Sony) first died, with no spinning (and no backups in the days of $500, 100MB drives), I was so frustrated I slammed down my fist on the top of the computer... and spun the drive up! After that I tried to avoid turning it off, or ever having the disc stop spinning, but if it did, I could always get it to start back up that way. I felt like Fonzi the IT guy...

      --

      Dude, I think I can see my house from here.

  14. Re:Hmmm. by asdfghjklqwertyuiop · · Score: 4, Interesting

    Until one day you find the files you're taring are corrupt...

  15. Article is useless, comments are good by NormalVisual · · Score: 5, Interesting

    I found an unusually large proportion of the follow up comments here to be (+1, Informative) and (+1, Interesting). TFA itself was total infomercial-tastic tripe, however.

    --
    Please stand clear of the doors, por favor mantenganse alejado de las puertas
  16. That is not a clean room by Anonymous Coward · · Score: 2, Interesting

    Look at the normal ceiling tiles and door that aren't air tight. Even the small (3 employee) company I work for has a better clean room than that. Their outfits were just for show.

  17. That's what I was thinking... by msimm · · Score: 2, Interesting

    I've disassembled crashed drives (ceased) to temporarily free the platters. Aside from removing the platter (so they could get to more then 25% of the data, WTF?) it didn't really read like they actually did much. Maybe part of the reason that they are all smoke-and-mirrors about the work (some proprietary software, you mean like something they paid for?) is that when you get right down to it the work *most* of these shops do simply isn't rocket science.

    --
    Quack, quack.
  18. Re:Hmmm. by donaldm · · Score: 2, Interesting

    Wouldn't backing your data up be cheaper? Your stating the logical thing to do but unfortunately most people have no idea how to backup their data and many that do could not be bothered living in denial as to the reliability of cheap disks. People like this only complain when the disk fails especially when it costs $1500 for a partial recovery which could have brought an acceptable backup solution in the first place and still have change to buy a nice stereo system for your PC and possibly a 20"+ LCD monitor (my son did this for well under $1000).

    Actually the cheapest solution for the home requires backup disks that are equal or greater in size to the data they backup (my current solution). This is a viable solution but you are definately subject to physical disasters such as fire and theft, still that is the chance you sometimes take for convience. Tapes are actually better but they start to get expensive however they are easy to put off-site (gets around the fire and theft issue). The same is true with DVD or Bluray disks but when you are trying to backup terra-bytes this can also get expensive and inconvenient.

    What is even worse are companies who have little if any backup strategies and there are quite a few of them. Some companies pay considerable amounts of money to do backups but many don't do any disaster recovery planing so when a disaster happens (and it will) the losses to the company due to downtime can be quite high, sometimes millions of dollars in lost revenue due to a recovery outage.

    Personally a backup solution which also includes disaster recovery should reflect what you perceive your data is worth.
    --
    There ain't no such thing as proprietary standards only proprietary formats. Standards are by definition open.