A possible performance bottleneck associated with insufficient network bands is mitigated to allow improvement of access performance of a storage system.
A storage system includes a first node with a storage medium of storage and a plurality of second nodes each with a controller function for the storage, and is communicatively connected to a host providing an access request to the storage. One of the plurality of second nodes is determined to be a node to which a controller function executing access processing on the storage is assigned on the basis of a first amount of data transfer between the second node and the host and a second amount of data transfer between the second node and the first node.