In order to assign logical devices efficiently to logical units, a disk control system that receives a process command for writing or reading of data from an information processing device, and performs a write or read process of data with respect to a logical device corresponding to a logical unit specified by that process command, includes means for managing logical devices, which are logical storage regions that have been set in a storage region provided by a disk drive, means for storing a correspondence between logical units, which are storage regions that have been set logically, and the logical devices, and means for assigning, when a process command has been received for a logical unit to which no logical device has been assigned, a logical device to that logical unit and performing processing with regard to that logical device.