A storage system includes a plurality of nodes connected with a network and configured to provide volumes, a plurality of drive units; and a management system. Each of the plurality of drive units consists of a plurality of storage drives and is accessible from one or more of the plurality of nodes without intervention of the other nodes. The management system or one of the plurality of nodes is configured to determine number of storage drives to be included in a new distribution range to distribute data of a first volume based on access frequency to the first volume.