My 3 month old 45 Gig IBM DTLA hard drive has suddenly developed 12,000+ bad sectors! I ran IBMs Disk Function Test utlity and it wants to erase the drive in an attempt to fix the bad sectors. My questions are.
1) What exactly are a bad sectors. I thought it was an area of the drive that is physically damaged, but if a low level formatting of the hard drive can repair them then my assumption is probably wrong.
2) What causes bad sectors. My harddrive has not been moved in months so physical shock can be ruled out. The problem developed right after I started running an FTP server, but shouldn't the drive be able to handle that. Could heat be a factor, I know this model runs rather hot. My computer crashed recently, could it being stuck reading or writting to the same area damaged the surface?
3) Is there any change of this DFT utlity fixing the problem and leaving me with a reliable hard drive.
Try 'Storagereview.com' discussion forum...they had a topic about this recently.
Someone else here might be able to help you as well.
1) Hard drives have two levels of information on them. The first is the low level format, which basically marks off the cylinders and sectors in the drive. A drive contains a given number of cylinders, each of which has a given number of sectors. Each sector can hold some amount of information.
The second level is the operating system's structure on top of that basic information. For example, Windows groups a number of sectors into clusters. It writes the information about the clusters, as well as a file allocation table (FAT), onto the drive to help it locate file data on the drive.
2) Drives can go bad on either of these levels. A low-level sector error can be caused by physical damage, mechanical drift of the drive stepper (this can happen over time), or power surge causing noise to be written to the drive. A high-level data error can be caused by software error (though modern OS's make this difficult to do), a virus, or anything that could cause a low-level sector error.
I recently found bad sectors soon after I installed 2 SCSI drives in my system. My main theory is that I touched the wrong thing after I installed them, while feeling the drives to see how hot they were getting. Unfortunately the bad sectors were in the directory table for the Windows\System directory, which meant I couldn't boot up.
Performing a low-level format will remark all the sectors and cylinders. Any physically bad sectors will be marked as well, so that the OS won't be able to use them. If you don't get any of those, you'll know at least the damage isn't physical. You'll then need to repartition the drive and reinstall anything you had there before. Backup what you can first, so at least you have something.
Fortunately I was able to back everything up to one of the other drives before doing all this. I didn't lose anything major, at least not that I know about yet :-D
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