The present invention is provided for producing check data or recovery data in a disk array. According to the present invention, a plurality of buffers receives and stores the data respectively for a plurality of operation units to perform operations to produce check data. An output selector selects one of the buffers and sends the check data to the coupled disk drive. When recovering the data in a disk drive, by using the buffers coupled to the other disk drives, the data or the check data stored in the other disk drives are sent to the operation units to perform operations on the data and the check data to produce recovery data. The recovery data is then sent to the disk drive to be recovered by selecting the buffer coupled to the disk drive to be recovered via the output selector. In addition, the buffers can be coupled to a plurality of input selectors, which are used for selecting to send data in one of the buffers to the coupled operation units.