Read/write disk drive having read ahead processor which returns a write command, currently being executed, to command queue and executes read command in response to confirmation that there is no overlap

摘要

A disk device having a read/write processing device to improve the efficiency of operations between write commands that have overlapping data, and to prevent delays in execution processing of starting commands. A read command advance processor unit that processes in advance the read commands for which there are unprocessed write commands in the command queue and a write command overlap data processor overwrites the existing write command write data overlap part when the new write command write data overlaps the write data from an existing write command.