An image forming apparatus includes a RAID control unit comprising an access request queue and an access request arbitrating unit configured to store access requests to a logical disk sent from an operating system in the access request queue on the basis of fetch order determination information, and to fetch the access requests. An access arbitration method for a RAID driver comprises the steps of storing the access requests in an access request queue on the basis of fetch order determination information, converting logical disk access information contained in access information corresponding to the access requests into physical disk access information, and supplying the access information containing the physical disk access information to a RAID controller.