Patent ID: 8316195

Claim:
A storage system, comprising: a storage apparatus that stores therein data used by an external apparatus; first and second temporary data storage units that temporarily store therein data to be written to the storage apparatus from the external apparatus or data read from the storage apparatus; a first data transfer controller communicatively coupled with the external apparatus, and the first and second temporary data storage units, and controls data transfer between the external apparatus, and the first and second temporary data storage units; a second data transfer controller communicatively coupled with the first and second temporary data storage units, and the storage apparatus, and controls data transfer between the first and second temporary data storage units, and the storage apparatus; a third data transfer controller communicatively coupled with the first and second temporary data storage units, that controls data transfer between the first and second temporary storage units, and performs a data processing function not included in the first and second data transfer controllers; and a data transfer control management unit that causes any one of a first data transfer process and a second data transfer process to be performed upon receipt of a data I/O request from the external apparatus, the first data transfer process executing data transfer between the external apparatus and the storage apparatus via the first temporary data storage unit under control of the first and second data transfer controllers, and the second data transfer process executing data transfer between the external apparatus or the storage apparatus and the second temporary data storage unit under control of the first and second data transfer controllers and executing data transfer between the first temporary data storage unit and the second temporary data storage unit under control of the third data transfer controller.