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Data Recovery Techniques For Dead Zip Disks?

Posted by timothy on from the choose-a-deity-and-start-praying dept.

Lkmyst writes "Recently I had a Zip 250 disk die on me after the obvious channels were checked and found to be too expensive for a college student at $200US + I looked to see if there was perhaps another method I could use. A *nix dd looks like it might work but I thought I would ask slashdot to see if anyone out there has had luck with zip disks the drive no longer recognizes."

44 comments

  1. Use your brain! by Anonymous Coward · · Score: 1, Insightful

    A *nix dd looks like it might work but I thought I would ask slashdot

    Instead of, oh I don't know... trying it?

    Please, anybody who is thinking of submitting an Ask Slashdot, read How To Ask Questions The Smart Way first. It covers things like RTFA and STFW, which a lot of Ask Slashdotters seem to be unaware of.

    1. Re:Use your brain! by Anonymous Coward · · Score: 3, Informative

      When recovering from damaged media, it's not a good idea to start trying lots of things on the original. There may be a limited number of reads left. You should do your research first.

      In this case, I would get a different, known to be good zip drive, and do a dd to get the whole image, and then try to work with just the image; only go back to the zip for a second read if you have to.

    2. Re:Use your brain! by jamus · · Score: 2, Informative

      I had a HFS+ partitioned drive start going bad on me (clicking very noisly). I determined that the disk couldn't read one of the first few sectors, but could read most of the drive just fine.

      I used dd to try to copy the drive, and got about 20gb out of 30gb of the drive, then the drive completely died.

      I tried to use a few disk recovery utilities on the web, to no avail. I found out that there's only two Master Directory Blocks, one at block 2, one at the next to last block. I had lost both.

      If I had done my research, I should have pulled the MDB first, and then tried to get the rest of the data. Instead, I have 20gb of garbage. A data recovery company might be able to pull files from the data I have, but I gave up at this point.

    3. Re:Use your brain! by mpmansell · · Score: 4, Informative

      Well, what nice, well informed piece of sarcasm.

      Maybe it would be a good idea to at least have some knowledge of the subject you're berating someone for BEFORE opening your mouth. You're less likely to get egg splattered.

      The original poster did the right thing in asking first. I used to do data recovery and there are times when a media has a very limited physical life left. While less common than with old floppies, even modern magnetic media can suffer from the magnetic material seperating from the disk. If this is the reason for failure then blindly doing something in the hope that it may work could seriously reduce the chances you have for recovery later.

      Perhaps you are aware of how much an ass you are by posting as an AC?

  2. Give it a go with dd by sporktoast · · Score: 1

    With your ZIP 250, you have the added advantage of having destinaiton media that has the exact same geometry as the original

    --
    In a related story, the IRS has recently ruled that the cost of Windows upgrades can NOT be deducted as a gambling loss.
  3. Spinrite by iantri · · Score: 4, Informative
    If you can read the disk at all, Spinrite may help you. It can recover data from any disk accessable to DOS, which includes Zip Disks (with the Iomega DOS driver), depending on the type of your Zip drive (I'm not so sure about USB drives, though there are some USB drivers for DOS).

    Despite the bullshit on the Gibson Research website, it essentially repeatedly reads bad data and uses some statistical analysis to determine whether each bit was more likely 1 or 0, depending on which came back most often.

    This page has some more information on Spinrite and Zip Disks.

    If you can't read the disk at all, I think you are screwed. Sorry.

    1. Re:Spinrite by iantri · · Score: 1
      I thought I would ask slashdot to see if anyone out there has had luck with zip disks the drive no longer recognizes."
      Sorry.. missed that part. :(

      Well, the information might be useful to someone at least.

    2. Re:Spinrite by dasunt · · Score: 3, Informative

      Despite the bullshit on the Gibson Research website, [the software] essentially repeatedly reads bad data and uses some statistical analysis to determine whether each bit was more likely 1 or 0, depending on which came back most often.

      You should be able to whip something up with dd to do something similar. Make n number of dd images. Write a quick perl program to read through all the images at the same time, figure out if the bit at i position is more likely to be a one or a zero, and write the more likely bit to a new image file. Then mount the new image file as a loopback device, or copy it and try to run some file checkers on the copy.

    3. Re:Spinrite by Spoing · · Score: 1
      1. You should be able to whip something up with dd to do something similar. Make n number of dd images. Write a quick perl program to read through all the images at the same time, figure out if the bit at i position is more likely to be a one or a zero, and write the more likely bit to a new image file. Then mount the new image file as a loopback device, or copy it and try to run some file checkers on the copy.

      dd does not investigate hardare. dd does bit copies and does not even do error correction. Spinrite -- while not a tool for deep analysis of dammaged media -- does have the ability to check for data errors and correct them.

      That said, I'd use dd as you've described on failing media before attempting to use any data recovery tools (if they look like they are necessary).

      --
      A firewall can not protect you from yourself. Turn off what you do not need. Do not use the firewall to do your work.
    4. Re:Spinrite by dasunt · · Score: 1, Interesting

      dd does not investigate hardare. dd does bit copies and does not even do error correction. Spinrite -- while not a tool for deep analysis of dammaged media -- does have the ability to check for data errors and correct them.

      Either I'm misunderstanding dd, or else you are misunderstanding me.

      Use dd to make several copies of the disk. Imagine, for argument's sake, that the disk is 20 bits long, and, for argument's sake, we make 3 copies.

      The copies then look like this:

      image.01: 00000010100010100100
      image.02: 00011010100010100010
      image.03: 00010010100010011000

      dd doesn't need to do error correction, we want it to figure out what it keeps reading. For example, dd keeps getting a different value for bits 4, 5, 15, 16, 17, 18 and 19.

      The perl script would then take the images dd gave us, figure out which bits are different, and then figure out the most common result is. For example, for bit #4, 1 is the most common result, so it would "probably" be correct. For bit #5, 0 is the most common result. Etc, etc.

    5. Re:Spinrite by fred+fleenblat · · Score: 3, Informative

      dd just reads sequentially and will probably just return the same garbage each time.

      Spinrite tries reading stuff in different order each time so that the head momentum, and thus positioning, is a bit different on each read attempt. It then analyzes the data that it read and tries to figure out the whole thing (incl. parity, likelyhood of real world ascii data, etc) not just averaging the bits.

    6. Re:Spinrite by Spoing · · Score: 1

      Thanks for repling to him. It's close to what I would have written -- except with fewer words!

      --
      A firewall can not protect you from yourself. Turn off what you do not need. Do not use the firewall to do your work.
    7. Re:Spinrite by dasunt · · Score: 1

      dd just reads sequentially and will probably just return the same garbage each time.

      My bad. The principle is sound though -- perhaps accessing the bad drive directly through perl, and grabbing the hdd testing routine from badblocks, it would be possible to do an analysis of the drive similar to the GRC's software.

    8. Re:Spinrite by Anonymous Coward · · Score: 1, Funny

      There is a remote, vanishingly small, tiny, almost inconceivable possibility that perl is not the right tool for this job.

    9. Re:Spinrite by Glonoinha · · Score: 2, Insightful

      When all you have is a hammer, all the world looks like a nail.

      --
      Glonoinha the MebiByte Slayer
    10. Re:Spinrite by whereiswaldo · · Score: 1

      Don't read requests work on the sector level? How could you determine what bits are most likely without much detail (even reading single bytes would have the same problem, wouldn't it)?

      I have to add my obligatory "iomega sucks" statement in here. Click of death is real, whether they acknowledge it or not. Proprietary removable media in general sucks anyway, especially when you have common formats like CD's and DVD's.

    11. Re:Spinrite by iantri · · Score: 1
      Take the information on this page with a large does of salt (Gibson Research likes shovelling shit), but my understanding is this this:

      You are right; reads happen at the sector level. However, they are normally discarded in the case of a bad read (and a read is re-attempted). Spinrite claims to access the hardware at a lower level so that it stores in memory the result of the defective read. When this is done repeatedly, theory has it that hopefully it will get a perfect read at least once, or, if that is not the case, get enough reads to guess at whether each bit in the sector is a 0 or 1 based on statistics.

  4. ddrescue by AeiwiMaster · · Score: 1

    You could try ddrescue or dd_rescue + dd_rhelp

    1. Re:ddrescue by danielrose · · Score: 1

      i second that!
      dd_rescue and dd_rhelp have both been a terrific help..
      I had to hack dd_rhelp to make it write the temp log to a location other than its default, as I run from read only media, and the default location is the source device with ".log" appended.
      In general, many many times better than dd alone

      --
      i hate pansy republicans
  5. Best and Only Way by Shadow_139 · · Score: 5, Funny

    You Need; Sharp Blade Clear nail polish Non-safety matches 1 Carefully crack open the disk on the two sides, use the blade in the small taps on each side. Remove the cotton covering. 2. Scrape a lot of match powder into a bowl (use a wooden scraper ONLY !!!!, metal might spark the matchpowder!) 3. After you have a lot, spread it evenly on the disk. 4. Using the nail polish, spread it over the match mixture, and Let it dry. 5. Carefully put the diskette back together and use the nail polish to seal it shut on the inside (where it came apart) 6. Run the Iomega Test Program on the Disk, and all will be well " Shit, speed lines are chasing me!"

    1. Re:Best and Only Way by Anonymous Coward · · Score: 1, Funny

      After that, try that great Thanksgiving turkey recipie in which you stuff the turkey with unpopped popcorn.

  6. Use VCHE by Anonymous Coward · · Score: 0

    I usually use vche to recover disks:

    http://www.grigna.com/diego/linux/vche/index.html

  7. NO! by Anonymous Coward · · Score: 0

    WHO THE FUCK MODDED THIS INTERESTING?!?!?!?!

    All this will do is burn up his Zip drive (and maybe house)!

    DAMMIT, think people!!

    i read it and laughed, then to realize it was modded "Interesting", not "Funny".

  8. Think just a little before working by wonkavader · · Score: 2, Informative

    Spinright and other ideas are clearly the way to go, but your disk died because of activity on it (most likely) and more activity with further compromise it.

    So:

    1. Try all these good ideas suggested here on a different ZIP disk. One which isn't important.

    2. Don't proceed with the same drive if you cannot get anything off any ZIP disk with your drive. Find another one. But only do that if the first one is completely screwed, as writing on a disk with multiple drives (for some floppy technologies, not sure about ZIP) is a great way to destroy a disk.

    3. Get your dd first: One BIG dd off the whole thing, so you have something to fall back on later, should your work blow up, and the disk turn to cabbage. Not sure of the dd command? Work it out on a DIFFERENT DISK (see #1), so you're not grinding on this disk a bunch of times. Just read it once for the dd, then run spinrite and that stuff to try to do the job right.

    Plowing through the dd will be unpleasant, you're only getting it as a last ditch, but get it FIRST.

  9. dd usage by terrencefw · · Score: 2, Informative

    if you're going to try and recoved data with dd, make sure you dd from the partition itself, ie: /dev/sda4 and use 'conv=sync,noerror' to make sure you don't end up with an image shorted than 250MB due to dd missing out the bits it can't read rather then replacing them with zeros. You may be able to mount the resulting file loopback and see what's left.

    --
    Like tinyurl, but one letter less! http://qurl.co.uk/
    1. Re:dd usage by danielrose · · Score: 1

      dd_rescue / dd_rhelp are much nicer to use on defective media, as by default they try again on errors, where as dd will skip

      --
      i hate pansy republicans
  10. Click of death? by itwerx · · Score: 2, Interesting

    While GRC's Spinrite is an awesome product (I've been using it for 15 years - since 1.0!) and it can also work on all types of removeable media and most all partition-types (Mac disks must be moved to a PC), I suspect that your disk's problem is more fundamental.
    However, while we're on the topic of GRC, Steve Gubson does have a different utility to cure the click'o'death on Zip disks.
    And while you're at it, you might even be able to get IOmega to replace it even if it's out of warranty!
    (Speaking of replacing, basic troubleshooting steps would suggest trying it in another drive too... :)

  11. Software... by Awestruckin · · Score: 0

    I use this software at work to pull important data off of damaged floppies and cd's all the time, it works very very well.

    http://www.jufsoft.com/badcopy/

    I've never tried it on a zipdisk, but it does work with them. Good luck. BTW, what was on your zip disk?? *wink wink nudge nudge*

  12. recoverdm by flok · · Score: 3, Informative

    Hi, You might want to give my program recoverdm a try. It is especially aimed at bad CD-roms, but is also usable for disks (harddisks/floppydisks/zipdisks). It repeatingly tries to read the sector and then uses statistics which outcome is supposed to be the most likely.

    --

    www.vanheusden.com - home of Multitail, HTTPing, CoffeeSaint, EntropyBroker, rsstail, bsod, listener, nagcon, nagi
  13. Be careful! by Anonymous Coward · · Score: 0

    (Speaking of replacing, basic troubleshooting steps would suggest trying it in another drive too... :)

    Not a great idea-- the click of death can be contagious.

    I had this happen at my last job. One person's Zip drive went, and when they moved to another machine to work while I checked it out, they put the bad Zip disk into that machine's Zip drive as well. Click.... click... click... We confirmed the second drive was hosed with a second blank, freshly-formatted in a good drive Zip disk and then placed in the second drive.

    Luckily it was the very late 90's and CD-R drives were becoming ubiquitous-- Iomega got no more of my then-company's money after that incident.

    1. Re:Be careful! by itwerx · · Score: 1

      Not a great idea-- the click of death can be contagious.

      Yeah, but if you look at the write-up on Gibson's utility you'll see that it can also be repaired.

  14. Define "die" by Zocalo · · Score: 4, Informative
    A little bit more specific please! Do you mean, the disk is suffering from the so called "Click of Death", or just that you can't get it to mount? If it's the former, then your best bet is to something like dd or SpinRite to try and pull as much data off the disk as possible.

    However, if it's the latter then you may just have a scrambled partition table which I found was prone to corruption when moving back and forth between Windows and Linux. For some reason Iomega uses partition table entry #4, which I suspect was the root cause of the problem. There also seemed to be a change in geometry between some disks, maybe caused by a reformat or something, I never did figure that one out. Anyway, I eventually came up with the following commands to restore a 250MB ZIP disk to full functionality (change /dev/hd* to suit):

    To recreate a valid partition table (you might want to check these values against a known good disk first):

    sfdisk -f -q -uS -C239 -H64 -S96 /dev/hdd << EOF
    0 0
    0 0
    0 0
    32 489440 6 *
    EOF

    To avoid some funky issues on Windows which doesn't seem to accept garbage in the first sector of a drive you will probably need to follow that with:

    dd if=/dev/zero of=/dev/hdd4 bs=512 count=1

    And finally, you can create a pristine new file system with the command:

    mkfs -t msdos /dev/hdd4

    Obviously if you run the last one then you are not going to have any filenames or pointers left, but the actual data will still be there. In any case, you would certainly want to make a backup image of the raw disk with dd first if at all possible.

    --
    UNIX? They're not even circumcised! Savages!
    1. Re:Define "die" by Piquan · · Score: 1

      Do you mean, the disk is suffering from the so called "Click of Death", or just that you can't get it to mount? If it's the former, then your best bet is to something like dd or SpinRite to try and pull as much data off the disk as possible.

      I have a HDD that's got some rare software on it, and it's suffering from what, as far as I can tell, is advanced Click of Death. It'll boot, sometimes get all the way to the Finder (old Mac), make a loud click, then spin down. Spin up, click, spin down, repeat every few seconds. Would a dd work for this advanced case, or do I need to investigate extreme measures?

  15. Kinko's... by bergeron76 · · Score: 1

    Are you certain it's the disk that's bad and not the drive? I would try taking the disk to Kinko's and see if you can read it on one of their Zip Drives. If so, you're in business. If not, as least you can be sure that the disk is at fault.

    --
    Don't think that a small group of dedicated individuals can't change the world. It's the only thing that ever has.
  16. Heat-stressed hard drives by tepples · · Score: 2, Informative

    It might be the effects of heat stress on the bearings. I've had two HDs die in an old Mac that way. I'd suggest trying to 'dd' a few percent of the hard drive at a time, waiting for it to cool down, and then repeat.

  17. AAGGLL Re:Spinrite by Anonymous Coward · · Score: 0

    I am not familiar with the tools being discused, but I was cruising at -1 for moderation...

    Could someone please explain to me why the parent to this comment was moderated "troll"?

    I'm going to up mod him in an hour unless someone can tell me wtf.

  18. dd_rescue to the rescue by Lord+Kano · · Score: 1

    I have never tried it on anything as fragile as a zip disk, but it has helped me recover files from a dead hard drive.

    LK

    --
    "Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
  19. The Tao of Backup by TheOtherChimeraTwin · · Score: 1
    It won't help with your current problem, but next time just restore from backup.

    http://www.taobackup.com

  20. FAT16 by nurb432 · · Score: 1

    its too bad he's not updated spinrite to support other filesystems.. If its NTFS or some unix format, spinrite refuses to even see the disk..

    --
    ---- Booth was a patriot ----
    1. Re:FAT16 by iantri · · Score: 1

      Spinrite 6.0 can do any filesystem.

  21. Spinrite has worked every time for me... by aquarian · · Score: 2, Informative

    Spinrite is well worth the 90 bucks. Not just for now, but if you have any kind of a disk crash in the future.

    I'm cheap as hell when it comes to software. Practially everything else I use is free, except Windows itself. But I had no trouble paying for Spinrite. It's the best software purchase I've ever made.

    There's info at grc.com specifically about Zip problems. Check it out.

  22. Try Spinrite 6.0... by aquarian · · Score: 1

    It does NTFS and Unix filesystems too.