Abstract: A disc array device for maintaining consistency of data. When write processing is interrupted and then restarted, new data may be stored in a nonvolatile memory and regeneration of parity may be impossible because data can not be read out normally from a disc device other than a disc device in which new data is to be written and a disk device for parity. In such a case, a special write executing unit overwrites the new data stored in the nonvolatile memory at a specified write position of the disk device in which new data is to be written.

Abstract: When write processing once interrupted is restarted, if new data is stored in a nonvolatile memory 34 and regeneration of parity is impossible because data can not be read out normally from a third disk device (for instance 32-2) other than a disk device (for instance 32-1) in which new data is to be written and a disk device (for instance 32-5) for parity, a data writing unit 113 in a special write executing unit 110 overwrites the new data stored in the nonvolatile memory 34 at a specified write position of an appropriate disk device (for instance 32-1).