SMART's "Reallocated Sector Count"?

[(PeteCresswell)]

From what I've read so far:

1) Reallocated Sector Count is not the whole story
bad-sectorwise. It only reflects sectors that
have been remapped to areas other than the designated
overflow area for that part of the disc. There may
be many more bad sectors that have quietly re-mapped.

2) Through some magic, the remapping process happens
when needed.


Correct so far?

If so, who does the re-mapping? What happens to the file that
was using the bad sector? I'm guessing that the part of the
file that was using the bad sector has it's bits copied to the
new sector. But presumably there was some sort of problem
reading that file... so does the file automatically have some
errors in it once moved?

Would it be correct to say that once a disc starts to bump it's
Reallocated Sector Count that it bears watching more closely? Is
there a rule of thumb per gigabyte of how many remapped sectors
constitute a warning?

 

[Yousuf Khan]

From what I've read so far:

1) Reallocated Sector Count is not the whole story
bad-sectorwise. It only reflects sectors that
have been remapped to areas other than the designated
overflow area for that part of the disc. There may
be many more bad sectors that have quietly re-mapped.

2) Through some magic, the remapping process happens
when needed.


Correct so far?

If so, who does the re-mapping? What happens to the file that
was using the bad sector? I'm guessing that the part of the
file that was using the bad sector has it's bits copied to the

The drive itself does the remapping. Sectors that are remapped are only
those sectors that were being written to, but were having a hard time
being written there. So after awhile the hard disk itself begins writing
that data to its reserve sectors instead. Since these sectors were being
overwritten anyways, it doesn't matter whether you're using the original
sectors or the reserve sectors.

Yousuf Khan