When data written into a volume (source volume) in a parity group in a storage apparatus is written into a volume (destination volume) in a parity group in a storage apparatus using a remote copy function, it is determined during the copy whether or not one or both of the following two specified conditions are satisfied for this set of volumes: (1) the performance of the destination volume after a failover is equal to or higher than the performance of the source volume before the failover; and (2) the performance of the destination volume is equal to or higher than the performance of the source volume during the copy. If the condition(s) is not satisfied, the storage apparatus in which the destination volume is defined is changed in configuration to satisfy the condition.