Some doubt with bad sectors!!!!!

[muna420]

Hi,

I am new to Hard drive technology, I have some doubts rgarding bad sectors.
What i got to know from my studies in internet , there are 2 types of bad blocks created by physical damage and creaded by logical damage (ECC error). Is it like in both the case (logical and physical) , the sectors are added to g-list , and reallocation is done for the bad sectors ?

If yes then if a sector is added to g-list , is it like that sector can never be used (but logically damaged sectors can be used ,i think as it might work properly after formatting of disk) ?


Please explain!!!!

thank you

[labtech]

Once the sector is marked as "bad" and its space gets reallocated, it can no longer be used, as in writing data to it.

I assume you have a drive that has bad sectors. What do you want to accomplish? What is your goal?

[muna420]

Thank you for replying. I support for some servers, in which for disks several errors comes up, so i am interested about those errors and their cause.

if a sector is found to have ECC error and it is un correctable (not physical damage) during read operation , what is the steps taken inside disk in this situation ,is it declared bad ?

Thank you

[labtech]

http://en.wikipedia.org/wiki/S.M.A.R.T.

Look at the SMART table for pretty detailed explanation.
Some of the IDs concerning general diagnostic are IDs: 05, 196, 197 and 198.

[Vulcan]

@muna420,

Thank you for replying. I support for some servers, in which for disks several errors comes up

Please supply (a) the make & models of all the disks for which errors were reported, (b) the OS involved (since it an OS which reports errors, it helps us to know how the errors were reported), and (c) the exact error message in each case. Since you said "disks" (plural) then, depending on the exact errors, it is possible that the problem is not with the disks themselves, but is elsewhere. (d) As labtech has mentioned (in his example, using (S)ATA SMART info), if you provide the SMART data for these disks, this will also allow readers here to better understand the likely health of the disks - but this is not an "exact science".

if a sector is found to have ECC error and it is un correctable (not physical damage) during read operation

How do you know that there is not (internal) physical damage? I don't understand how you already know the cause of the errors.