And possibly some broken drives may also return you something that
they think is good data but really is not (shouldn't happen since
both disks and cables should be protected by checksums, but hey...
you can never be absolutely sure especially on very big storages).
It happens because
- There is limited if any protection on the PCI bus generally
- Many PC systems don't have ECC memory, ECC cache
- PATA does not CRC protect the command block so if you do enough PATA
I/O (eg you are a US national lab ..) you *will* eventually get a bit
flip that gives you the wrong sector with no error data. SATA fixes that
one.
- Murphy is out to get you..
Should IDE driver read back parameters after writing them before issuing
the command? That should fix this problem. (except when command is written
badly)
Not seen that, although they do move stuff aorund in their internal
block management of bad blocks. I've also seen hardware errors that lead
to data being messed up silently.
I have seen one WD drive bought in 2003 having error in its firmware in
cache-coherency code --- if you read and write 256 sectors to the same
places with some pattern repeatedly (with direct IO), it will discard a
write. It happens only with 256-sector writes, maybe some part of firmware
treats 256 as 0. Maybe I create testcase sometimes.
Mikulas
Alan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
