An embodiment of this invention is a storage management system including a processor and a storage device to manage a storage system having one or more copy functions. The processor locates data designated to determine a backup method. The storage device stores copy function management information on the one or more copy functions of the storage system. The processor refers to the copy function management information to ascertain the unit of copy operation of each of the one or more copy functions. The processor determines a candidate for a copy function of the storage system to be used to back up the designated data depending on the data configuration in a volume holding the designated data and the unit of copy operation of the candidate for the copy function.