Sorry for the confusion, I try to make clear.
Generally, the Reallocation Event Count counter should count and show all initiated reallocation events: both
1) the successfully completed events: when the real reallocation happens, so the original sector is no longer used and all further reads/writes are redirected to the spare area. Then as we'd expect, the Reallocated Sectors Count attribute increases when the Reallocation Event Count increases.
2) the "failed" reallocation events: when the reallocation is not finished, so the above mentioned redirection does not happen, the original affected sector remains used. Then the Reallocated Sectors Count attribute does not increase, only the Reallocation Event Count increases.
We may think the 2nd case is a bigger problem as then somehow the reallocation can't be completed, for example the original sector is so seriously damaged so the hard disk drive can't recover during reallocation, that's why the reallocation event can't be finished.
But no, in most cases, the situation is exactly the opposite: during the reallocation procedure, the hard disk first tries to read all data from the affected sector and move that data to the spare sector. And if the drive can read the data correctly, completely, without the need of CRC error correction and without any significant delay - then it can assume that the original sector is correct, working, can hold the data - so no need to reallocate it.
It means the sector can still be used, "the data area is perfect" - as displayed by Hard Disk Sentinel.
Anyway, such reallocation events may indicate other kind of problems and this is exactly these are important to be detected and reported.
For example, it may indicate *real* problems with the sector and the counter may increase when the sector should be really reallocated, just the user can't wait the end of reallocation and performs a forced reset / power off (as during the reallocation the hard disk is not responding and sometimes the system seems frozen - as described on
www.hdsentinel.com/smart )
Sometimes operating environment (power cable, data cable, connections, power supply and so) can cause that the hard disk can't work properly, so it may be good idea to check these too.
And in such situations, it is good idea to perform some intensive testing, exactly as described at
http://www.hdsentinel.com/faq.php#tests
to verify the situation, reveal and stabilize problems.
And ideally if the counter does not increase and the tests show no problems, the counter can be cleared in Hard Disk Sentinel, so then only possible new issues will be reported.
For more information, please check
http://www.hdsentinel.com/faq_repair_ha ... _drive.php
