A disk controller for controlling disk devices for storing redundant data distributed thereacross, the disk devices providing a logical volume, the disk devices including pool volumes allocatable to one of the logical volume. The disk controller includes a memory for storing information indicating a relationship between the pool volumes and the logical volume; and a processor for performing data reconstruction in accordance with a failure of the disk devices, a process of the data reconstruction, the processor being configured to detect an error in a part of the pool volumes included in the other disk devices when reading data from the pool volumes included in the other disk devices, determine whether the detected pool volume is allocated to the logical volume in reference to the information, and initialize the part of the detected pool volume when the detected pool volume is unallocated to the logical volume.