STORAGE MANAGEMENT DEVICE, INFORMATION PROCESSING SYSTEM, STORAGE MANAGEMENT METHOD, AND RECORDING MEDIUM

A storage management device includes: a memory; and a processor coupled to the memory. The processor executes a process including: managing a plurality of storages in a system in which a data storage destination is switched between a first storage and a second storage; first performing management to cause the first storage to hold data as master data and cause the second storage to hold data equivalent to the master data as backup data; and second performing management to cause the second storage to hold update data for the backup data held in the second storage independently from the backup data and cause a third storage different from the first storage and the second storage to duplicate the update data when the data storage destination is switched from the first storage to the second storage.