Each of multiple nodes has a processor, a memory, and a storage region. In a process of updating a stripe, the processors generate an intermediate parity from a data block included in a first node and a parity block included in the first node and included in the stripe to be processed, transfer the intermediate parity to a second node, cause the intermediate parity to be stored as a parity in a block of the second node, and configure the stripe with the data block from which the intermediate parity has been generated, the block storing the parity, and a data block included in a node other than the first and second nodes and included in the stripe to be processed.