G-List, Translator and when is what done

[maddin]

Hello,

I have a general question about how that all work together. I know what the translator does and what the G-list is but how they work together and when?

Take for example an attempt to image a drive - when the drive run into a bad sector is the G-list immedeatly updated or will the HDD remember the bad sector in RAM and update the G-list in the idle time? If it's updated in the idle time the replacing of a sector could be stopped with powering the drive off and back on - right?

And how work the translator with the G-list together? Does the translator read the G-list alyways or does the translator get updated somehow when a bad sector is replaced?

Thanks.

[pepe]

If reallocation is enabled, then any unreadable sector will be added as a candidate to Glist, it is also saved, not cached.
candidates become real relocations at the next write to them. Drive will first try to write the sector at its original location and if it cannot be read back, it will be reallocated, as in, new data will be written to spare area and the entry will become relocated instead of a candidate. It probably also becomes a relo if the orig sector can be read finally but does not get stable after a rewrite.
Plist, on the other hand, is not changed during normal operation, the LBAs in there are skipped. Say LBA 1000 is in Plist, it will never be read, PBA 1001 will become LBA 1000, and so on.
The whole thing is pretty much vendor specific, the defect management configuration, BGMS actions, etc

pepe

[maddin]

If reallocation is enabled, then any unreadable sector will be added as a candidate to Glist

OK that mean as more bad sectors occur as more the head has to jump arround.

It probably also becomes a relo if the orig sector can be read finally but does not get stable after a rewrite

So the translator must work with P-list and G-list and Relo-list. Regenerating the translator for each reallocation would be quite a lot of work. But if the lists grow we get a problem with the space in RAM.
Or is there also some list within the translator which get updated? How is that done?

The whole thing is pretty much vendor specific, the defect management configuration, BGMS actions, etc

That for sure. I just want to get some better picture how that things work together. And I try to understand how much work a reallocation really is and there somewhere after the relo-entry must be also an SMART update.

[pepe]

Glist is pretty much limited in capacity, some thousand entries usually, so it won't eat up ram. Depending on the brand the fw fails some way when it gets full.
yes, smart is usually updated as well, but it is done in regular intervals anyway. (if it is not disabled)

pepe

[terminator2]

Often with seagate drives I could read all sectors with one head and get large bad sectors on another. In case both heads are healthy , how to work on these drives ?
Which system files to work with .What to do with Glist and other lists .I would like to know all about this,

[pepe]

if heads are good, then surface must be bad... nothing to do with it.

pepe