A storage system adapted to be coupled to a plurality of host devices via a fiber channel. The storage system including a plurality of storage devices, at least a portion of the plurality of storage devices corresponding to a logical unit of a plurality of logical units, the logical unit having a logical unit number (LUN). The storage system also including a storage control device having a cache memory and controlling to store data, addressed to the LUN, into the portion of the plurality of storage devices. The storages system also including an input device being adapted to be used to set information, which is used to prevent an unauthorized access to the logical unit and which corresponds to a relationship between a host device of the plurality of host devices and the logical unit.