Request scheduling method, request scheduling apparatus, and request scheduling program in hierarchical storage management system

摘要

A request scheduling for scheduling requests to a secondary recording media while minimizing the frequency of recording-medium mounting/removing events in a secondary storage unit of an HSM (hierarchical storage management) system by searching for one or more request(s) processed or to be executed as executable on a drive unit, in units of the drive unit. According to the searching, detecting one or more generated read request(s) to read data from a recording medium mounted on the drive unit, and setting the drive unit as an exclusive drive for the read request(s). And scheduling a drive unit having an elapsed time period for a mounted recording media not exceeding a predetermined time period to execute an executable request by priority.