A control method for controlling a recording/reproducing apparatus having plural storage units and an equipment to which the recording/reproducing apparatus is connected. The recording/reproducing apparatus has first and second storage units in which data and management data are stored. The equipment, to which is connected the recording/reproducing apparatus, has a third storage unit in which are stored the data and the management data. It is detected whether the equipment to be connected to the recording/reproducing apparatus has been connected to the recording/reproducing apparatus. If such connection is detected, the management data are read out from the first and second storage units. Based on the read-out management data and the management data stored in the third storage unit of the equipment, connected to the recording/reproducing apparatus, new management data, supervising the first to third storage units as one storage unit, is generated. The writing and readout for the plural storage units are controlled based on the generated new management data.