A storage system is composed of storage apparatuses each separately installed at three sites for the purpose of disaster recovery, wherein data stored in one of the storage apparatuses designated as a replication source is also managed in one of the other two storage apparatuses designated as a replication destination, such that in the event of a failover execution request from an information processing apparatus, data stored in the storage apparatus designated as the replication source is managed also in the storage apparatus of the other two storage apparatuses designated as a spare.