Patent ID: 8370578

Claim:
A storage controller which exercises control of data between a host system and a storage apparatus, comprising: a data transfer control unit which exercises control to transfer the data on the basis of a read/write request from the host system; a cache memory which is connected to the data transfer control unit via a first parallel bus and which stores the data transferred from the data transfer control unit; a control unit which is connected to the data transfer control unit via a serial bus and which instructs the data transfer control unit to perform a transfer control operation; and a local memory which is connected to the control unit via a second parallel bus and which stores the data transferred from the data transfer control unit via the control unit, wherein the control unit executes cache segment selection processing in which the control unit decides to assign, from a cache segment of either the cache memory or the local memory, a storage area which stores the data on the basis of an operating rate of the control unit and a path utilization of the first parallel bus.