Patent ID: 8347032

Claim:
An image forming apparatus having a Redundant Array of Inexpensive/Independent Disks (RAID) control unit, the RAID control unit comprising: an access request queue; an access request arbitrating unit configured to store access requests to a logical disk, sent from an operating system (OS), in the access request queue on the basis of fetch order determination information and to fetch the access requests; and a plurality of pre-access request queues configured to store the access requests corresponding to respective logical disks, wherein the fetch order determination information includes priority levels of each of the logical disks and the number of pending access requests to each of the logical disks, wherein the access request arbitrating unit is further configured to store the access requests in the access request queue at a predetermined timing in such a manner that the higher the priority level of the logical disk to which the particular access request is directed and the greater the number of pending access requests to the logical disk to which the particular access request is directed, the higher the priority given to the particular access request, and wherein the access request arbitrating unit is further configured to store each of the access requests in the one of the pre-access request queues that corresponds to the logical disk to which the access request is directed.