Patent ID: 7013364

Claim:
A storage subsystem including a storage controller and a plurality of storage systems, said storage controller comprising: a storage selector for selecting one of the storage systems which processes an access request of a file unit received from an external device; and a unit for transmitting said access request of the file unit to the storage system selected by said storage selector, said storage system comprising: a main controller for controlling said storage system; and a media section for storing data therein, wherein said main controller analyzes said received access request of the file unit and executes operation according to said analysis; wherein, when said access request is a read request of data stored in said media section, said main controller converts the data of a block unit stored in said media section into data of a file unit and outputs the file unit data to said storage controller; and wherein, when said access request is a writing request of data received from said external device, said main controller converts data of a file unit received from said external device into data of a block unit and stores the block unit data in said media section.