A computer system includes a host unit that issues a request of an I/O processing to a volume VOL, a local pool control unit that is in charge of management of a local pool based on a storage area of a drive of one node, and a global pool control unit that is in charge of management of a global pool based on a plurality of local pools, wherein the global pool control unit controls transmission of target data of the I/O processing performed by the host unit based on a commonality relationship among a first node that is formed with the host unit performing the I/O processing, a second node that is formed with the global pool control unit, and a third node that is formed with the local pool control unit managing the local pool.