Fujitsu MPB3052AT, MPB3054AT, MPB3032AT, MPB3021AT, MPB3043AT manual Mis-hit data Empty data

(3)Sequential read

When the disk drive receives the read command that targets the sequential address to the previous read command, the disk drive starts the read-ahead operation.

a.Sequential command just after non-sequential command

When the previously executed read command is an non-sequential command and the last sector address of the previous read command is sequential to the lead sector address of the received read command, the disk drive assumes the received command is a sequential command and performs the read-ahead operation after reading the requested data.

1)At receiving the sequential read command, the disk drive sets the DAP and HAP to the sequential address of the last read command and reads the requested data.

HAP

Mis-hit data Empty data

DAP

2)The disk drive transfers the requested data that is already read to the host system with reading the requested data.

HAP

Mis-hit data Requested data Empty data

DAP

3)After completion of the reading and transferring the requested data to the host system, the disk drive performs the read-ahead operation continuously.

HAP

Mis-hit data Requested data

Read- ahead data

Empty

data

DAP

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