Disk control unit for holding track data in cache memory

摘要

A cache memory holds data of a disk unit on a track unit basis. Recording format information of the track in each disk unit is held in an LTD. For a write request from an upper apparatus, in case of a hit of the cache memory, a write cache control unit finishes a writing process on the cache memory and reports an end of process to the upper apparatus. In case of a mishit of the cache memory, a recording format is analyzed with reference to the LTD and a record position on the track to be developed in the cache memory is recognized, the writing process is finished on the cache memory and an end of process is reported to the upper apparatus.