Patent ID: 8412884

Claim:
A storage system for storing data requested by a host computer to be written, the storage system comprising: a host interface coupled to the host computer; a storage device for storing the data requested by the host computer to be written; a disk interface connected to the storage device; at least one processor for processing the data requested to be written; a cache memory for storing the data requested by the host computer to be written; and a cache controller for controlling data inputs to and outputs from the cache memory, wherein: the cache memory includes a first memory which can be accessed by way of either access that can specify an access range by a line or access that continuously performs a read and a write; the cache controller includes a second memory which has a higher flexibility than the first memory in specifying an access range; and the cache controller includes an access destination determination unit for determining an address of an access destination upon reception of a request for an access to the cache memory from the at least one processor; the access destination determination unit holds access destination information which associates a storage area of the second memory with an address space of the first memory; and the cache controller is configured to: switch a request for an access to a specific address into an access to a corresponding address in the second memory; wherein the at least one processor is configured to: back up data held in the second memory to the first memory; stop a function of the access destination determination unit; change a configuration of a device installed in the storage system or detect a change in the configuration of the device installed in the storage system; determine a place to store control information related to the device based on configuration information after the change of the configuration of the device; set the determined place to store the control information to the access destination information; migrate at least part of the control information held in the first memory to the second memory in accordance with the determined place to store the control information; and resume the function of the access destination determination unit after the migration.