A first node retains node management information for managing each of the nodes, presence or absence in the first node of a transfer target data set, a write destination, which is a strip in a node area of the node. Concerning the second nodes, this is each of the nodes other than the first node, the first node: (A) when specifying from the node management information that there are two or more transfer target data sets, write destinations that are respectively two or more strips in a node area of the second node, specifies two or more intra-node positions respectively corresponding to the two or more transfer target data sets; and (B) transmits, to the second node, one command for transfer, transfer targets of which are two or more transfer target data sets respectively present in the specified two or more intra-node positions.