CONTROLLER DEVICE, DISK CONTROLLER, AUXILIARY STORAGE DEVICE, COMPUTER SYSTEM AND AUXILIARY STORAGE DEVICE CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To execute detailed analysis and prediction by an outside controller in reponse to a true request from an application, and to issue a look-ahead request to an auxiliary storage device such as an HDD. SOLUTION: An HDC card 21, which stores data and is connected to an HDD device 22 having a cache memory, is provided with an access request trace part 61 for directly tracing a true access request from an application program to be executed by a host from the application program, a speculative request deciding part 62 for deciding a speculative request estimated in the future based on the traced true access request, and an HDC 31 for issuing the decided speculative request to the HDD device 22.