Patent ID: 7096372

Claim:
A storage control device comprising: a first I/O control unit including a channel control unit coupled to an information processing device and receiving a data I/O request from the information processing device, a disk control unit connected with one or more HDDs (Hard Disk Drives) storing data and reading/writing data from/to the HDDs according to the data I/O request and a cache memory for storing data communicated between the channel control unit and the disk control unit; a second I/O control unit whose current consumption is approximately equal to that of the first I/O control unit; two or more first AC/DC (Alternating-Current/Direct-Current) power supply devices receiving AC power and supplying DC power to the first I/O control unit; two or more second AC/DC power supply devices receiving AC power and supplying DC power to the second I/O control unit; and at least three AC power supply devices each having a circuit breaker that receives AC power supplied from outside and supplies the AC power to the first and second AC/DC power supply devices, and interrupts the supply of AC power when current exceeding a preset level passes, wherein: if one of the at least three AC power supply devices stops supplying power, other ones of the at least three AC power supply devices cause both of the first and second I/O control units to conduct, and each of the first and second AC/DC power supply devices includes a current balancing circuit that is used to equalize output currents supplied from the first and second AC/DC power supply devices to the first and second I/O control units even if the one of the at least three AC power supply devices stops supplying power.