Hard Disk Failure
Quoted 2 lines
no. e2fsprogs might cause data loss, but not
physical damage.
This reminds me of something I read once.
In his book, Takedown, Tsutomu Shimomura (forgive me if that's spelled wrong) wrote a few short paragraphs about how he was able to move the head-arm of a magnetic disk drive back and forth with software commands. He could tell the head-arm to go to any cylinder on the drive, he wondered what would happen if he tried to send it to a cylinder that was outside the physical limits of the drive. He told the drive (a 200 cylinder drive) to goto cylinder 4000. The drive actually tried to go to that cylinder and caused a hardware failure in the process.
Is it still possible for software to damage hardware in this fashion or is hardware smarter now? Do drives know not to try and access a cylinder that is outside their physical limits?
Quoted 4 lines · rtilley
Is it still possible for software to damage hardware in this fashion or is hardware smarter now? Do drives know not to try and access a cylinder that is outside their physical limits?
I guess not :
Recently I moved one drive from one old system to a new one. The new BIOS couldn't be configured to use the old geometry -> I couldn't use the drive to boot (unless repartitioning the 120GiB beast).
During the migration process I tried different geometry settings and at several times the cylinder number was way above the drive's actual limit. I could hear loud "bumps" when the drive accessed the higher cylinders. Each time I rushed to the reset button...
This was with a SiS735 chipset and a Maxtor 4G120J6.
LB.
Quoted 5 lines
Quoted 2 lines
no. e2fsprogs might cause data loss, but not
physical damage.This reminds me of something I read once.
Quoted 9 lines
In his book, Takedown, Tsutomu Shimomura (forgive me if that's spelled wrong) wrote a few short paragraphs about how he was able to move the head-arm of a magnetic disk drive back and forth with software commands. He could tell the head-arm to go to any cylinder on the drive, he wondered what would happen if he tried to send it to a cylinder that was outside the physical limits of the drive. He told the drive (a 200 cylinder drive) to goto cylinder 4000. The drive actually tried to go to that cylinder and caused a hardware failure in the process.
It's actually possible to make some old mainframe hard disks 'walk' across the floor, by doing various seeks across the disk :-).
Quoted 3 lines
Is it still possible for software to damage hardware in this fashion or is hardware smarter now? Do drives know not to try and access a cylinder that is outside their physical limits?
Since modern hard disks are not accessed by their physical geometries', I would imagine that it would be rare to be able to cause physical damage to a disk by sending a reference to an out of range sector. The disk has to translate the sector you send to it in to it's real geometry anyway, so there should be no way to translate an invalid sector in to an invalid physical geometry location, which it could then not seek to.
John
Quoted 30 lines · John Bradford
Quoted 5 lines
Quoted 2 lines
no. e2fsprogs might cause data loss, but not
physical damage.This reminds me of something I read once.
Quoted 9 lines
In his book, Takedown, Tsutomu Shimomura (forgive me if that's spelled wrong) wrote a few short paragraphs about how he was able to move the head-arm of a magnetic disk drive back and forth with software commands. He could tell the head-arm to go to any cylinder on the drive, he wondered what would happen if he tried to send it to a cylinder that was outside the physical limits of the drive. He told the drive (a 200 cylinder drive) to goto cylinder 4000. The drive actually tried to go to that cylinder and caused a hardware failure in the process.
It's actually possible to make some old mainframe hard disks 'walk' across the floor, by doing various seeks across the disk :-).
Quoted 3 lines
Is it still possible for software to damage hardware in this fashion or is hardware smarter now? Do drives know not to try and access a cylinder that is outside their physical limits?
Since modern hard disks are not accessed by their physical geometries', I would imagine that it would be rare to be able to cause physical damage to a disk by sending a reference to an out of range sector. The disk has to translate the sector you send to it in to it's real geometry anyway, so there should be no way to translate an invalid sector in to an invalid physical geometry location, which it could then not seek to.
Quoted 1 line
John
In a previous life, I wrote a Disk utility called SPINOK. It was posted on my BBS (The PROGRAM EXCHANGE) and became the major product of a company that made a (copy, clone, theft?) called Spin-Rite. This utility would determine the optimum interleave for a disk drive. It would first save the data from a track into memory, then format the track, then write the data back.
Most disk drives in those days used the ST-506 interface, however, when the IDE interface became popular, it was necessary to determine the geometry of the drive before attempting to format a track with the new interleave. This was necessary because the track headers contain the cylinder as well as the head and sector. If this gets written wrong, you have the slowest drive you can imagine!
So, the utility tries first to determine the number of cylinders, then the number of sectors per track, then the number of heads. It does this by trying to read head 0 (all drives have head 0), sector 1 (all drives have sector 1), cylinder 1024 (the maximum possible in those days. It would "work backwards" to determine the whole geometry. It used Newton's method for quick convergence so it didn't have to try all combinations.
It was possible for a disk to get "stuck" if it seeked (sought) to a cylinder that was too high. However, a power-off reset would fix it because, during power up, the drive always moved the head-arm throughout the platters to minimize "stiction" and get the heads flying.
Having mucked with many disk drives, I don't thing it's possible to kill them from "commands" unless the command is "upload firmware". If you happen to upload Linux instead of the correct firmware, the drive may "go penguin" and all bets are off!
Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips). Why is the government concerned about the lunatic fringe? Think about it.