Abstract: To prevent an excessive increase of a dirty data amount in a cache memory. A processor acquires storage device information from each of storage devices. When receiving a write request to a first storage device group from a higher-level apparatus, the processor determines whether a write destination cache area corresponding to a write destination address indicated by the write request is reserved. When determining that the write destination cache area is not reserved, the processor performs, on the basis of the storage device information and cache information, reservation determination for determining whether to reserve the write destination cache area. When determining to reserve the write destination cache area, the processor reserves the write destination cache area. When determining not to reserve the write destination cache area, the processor stands by for the reservation of the write destination cache area.

Abstract: To prevent an excessive increase of a dirty data amount in a cache memory. A processor acquires storage device information from each of storage devices. When receiving a write request to a first storage device group from a higher-level apparatus, the processor determines whether a write destination cache area corresponding to a write destination address indicated by the write request is reserved. When determining that the write destination cache area is not reserved, the processor performs, on the basis of the storage device information and cache information, reservation determination for determining whether to reserve the write destination cache area. When determining to reserve the write destination cache area, the processor reserves the write destination cache area. When determining not to reserve the write destination cache area, the processor stands by for the reservation of the write destination cache area.