STORAGE SYSTEM, RECORDING MEDIUM STORING DATA REBALANCING PROGRAM, AND DATA REBALANCING METHOD

A storage system includes a plurality of storing devices configured to store data, a cache memory configured to hold data, an access control unit configured to make an access to any one of the plurality of storing devices when an access request for reading of target data or writing of the target data is made from an information processing terminal, and to store the target data in the cache memory, and a writing unit configured to write the target data stored in the cache memory in the storing device which has not stored the target data among the plurality of storing devices.