In a storage system in which a pair is configured by a remote copy, when a fault occurs in the pair, data to be lost is determined. Provided is a management computer connected to a storage system, in which the storage system includes: a primary logical volume in which data is stored and an secondary logical volume in which a replication of the data stored in the primary logical volume is stored; the primary logical volume and the secondary logical volume form a pair; the management computer comprises a data management module for managing data stored in the primary and secondary logical volumes; and the data management module obtains an event regarding the pair, determines whether the event is caused by a fault occurring in the pair, determines data made to be inconsistent by the fault in the case where the event is caused by the fault, and outputs information on the inconsistent data.