Destaging method for storage apparatus system, and disk control apparatus, storage apparatus system and program

Abstract

A destaging method is provided for destaging a storage apparatus system comprising a disk control apparatus that functions as a data storage unit and is provided with disk apparatuses and a first cache memory, and an information processing apparatus that is connected to the disk control apparatus and provided with a second cache memory. The method includes a first step, in which upon an interruption of the functions of the disk control apparatus as the storage unit for the information processing apparatus, the information processing apparatus transfers to the first cache memory data scheduled to be written onto the disk apparatuses and that is currently stored in the second cache memory, and a second step, in which the disk control apparatus manages data to be stored in the disk apparatuses by dividing the data into a plurality of management groups and, when all data that belong to one of the management groups remained in the second cache memory and scheduled to be written onto the disk apparatuses are ready in the first cache memory, beginning writing onto the disk apparatuses the data that belong to the one of the management groups remaining in the first cache memory are scheduled to be written.