Storage system for optimally controlling a plurality of data transfer paths and method therefor

Provided is a storage system, which includes: a storage medium for storing data; a plurality of ports for connection to a network; and a control section, and in which: the network is connected to another storage system; the plurality of ports include a first port; the plurality of ports involve a plurality of data transfer paths extending from the plurality of ports to the another storage system, which include a first data transfer path extending from the first port to the another storage system; and the control section: transmits data to be stored into the another storage system from the plurality of ports; acquires performances of the plurality of data transfer paths; and transmits, if the performance of the first data transfer path is lower than a predetermined threshold value, the data to be stored into the another storage system from the plurality of ports excluding the first port.