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Data Recovery Techniques For Dead Zip Disks?
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."
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.
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!"
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!
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?