HGST TRAVELSTAR 80GN 30GB ATA5 08K0910 User Manual

Product codes
08K0910
Page of 214
Travelstar 80GN Hard Disk Drive Specification
88
11.14  Reassign Function
The Reassign Function is used with read commands and write commands. The sectors of data for reassignment are 
prepared as the spare data sector. The one entry can register 256 consecutive sectors maximum.
This reassignment information is registered internally, and the information is available right after completing the 
reassign function. Also the information is used on the next power on reset or hard reset.
If the number of the spare sector reaches 0 sector, the reassign function will be disabled automatically.
The spare tracks for reassignment are located at regular intervals from Cylinder 0. As a result of reassignment, the 
physical location of logically sequenced sectors is dispersed.
11.14.1   Auto Reassign Function
The sectors that show some errors may be reallocated automatically when specific conditions are met. The spare 
tracks for reallocation are located at regular intervals from Cylinder 0. The conditions for auto-reallocation are 
described below.
Nonrecovered write errors
When a write operation can not be completed after the Error Recovery Procedure (ERP) is fully carried out, the 
sector(s) are reallocated to the spare location. An error is reported to the host system only when the write cache is 
disabled and the auto reallocation fails.
If the number of available spare sectors reaches 16 sectors, the write cache function will be disabled automatically.
Nonrecovered read errors
When a read operation fails after a defined ERP is fully carried out, a hard error is reported to the host system. This 
location is registered internally as a candidate for the reallocation. When a registered location is specified as a target 
of a write operation, a sequence of media verifications is performed automatically. When the result of this 
verification meets the criteria, this sector is reallocated.
Recovered read errors
When a read operation for a sector fails once and then is recovered at the specific ERP step, this sector of data is 
reallocated automatically. A media verification sequence may be run prior to the relocation according to the 
predefined conditions.