Hitachi hard disk 0J11285 500 GB 2.5 " 8 MB 0J11285 Ficha De Dados
Códigos do produto
0J11285
Z5K500 OEM Specifications
63
12.10
12.11
Write Cache Function
Write cache is a performance enhancement whereby the device reports completion of the write command
(Write Sector(s) and Write Multiple) to the host as soon as the device has received all of the data into its
buffer. The device assumes responsibility to write the data subsequently onto the disk.
(Write Sector(s) and Write Multiple) to the host as soon as the device has received all of the data into its
buffer. The device assumes responsibility to write the data subsequently onto the disk.
While writing data after completed acknowledgment of a write command, soft reset or
COMRESET does not affect its operation. But power off terminates writing operation
immediately and unwritten data are to be lost.
immediately and unwritten data are to be lost.
Flush cache, Soft reset, Standby, Standby Immediate and Sleep are executed after the
completion of writing to disk media on enabling write cache function. So the host system can
confirm the completion of write cache operation by issuing flush cache command, Soft reset,
Standby command, Standby Immediate command or Sleep command, and then, by confirming
its completion.
confirm the completion of write cache operation by issuing flush cache command, Soft reset,
Standby command, Standby Immediate command or Sleep command, and then, by confirming
its completion.
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 up to 256 (512
byte/sector format) or 32 (4KB sector format) consecutive physical sectors maximally.
reassignment are prepared as the spare data sector. The one entry can register up to 256 (512
byte/sector format) or 32 (4KB sector format) consecutive physical sectors maximally.
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.
completing the reassign function. Also the information is used on the next power on 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 will be dispersed.
reassignment, the physical location of logically sequenced sectors will be dispersed.
12.11.1
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.
The spare tracks for reallocation are located at regular intervals from Cylinder 0. The conditions for
auto-reallocation are described below.
Non recovered 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.
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.
automatically.
Non recovered read errors
When a read operation fails after 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 verification is performed
automatically. When the result of this verification meets the criteria, this sector is reallocated.
When a read operation fails after 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 verification 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 failed once then 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 pre-defined conditions.
When a read operation for a sector failed once then 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 pre-defined conditions.