Patent ID: 8041911

Claim:
A remote copy system, comprising: a first host computer; a first storage system operatively connected to the first host computer and including a first volume; a second host computer; and a second storage system operatively connected to the second host computer and the first storage system, and including a second volume forming a pair relationship with the first volume, wherein, when the first storage system receives one of write commands from the first host computer, the first storage system stores data accompanied with the write command in the first volume, and creates a journal data to which a time information is added based on a time stamp included with said one of the write commands, wherein the second storage system receives the created journal data from the first storage system, and updates the second volume based on the received journal data, wherein the first host computer acquires a valid recovery point objective, depending on an operating status of the second storage system pertaining to either the latest time information among time information of each journal data that the second storage system received or the latest time information among time information of each journal data that updates the second volume, wherein the first storage system includes: a first copy management table that manages the pair relationship; a first journal volume configured to temporarily store the created journal data; and a first journal volume management table that manages the first journal volume, and wherein the second storage system includes: a second copy management table that manages the pair relationship; a second journal volume configured to temporarily store the received journal data; and a second journal volume management table that manages the second journal volume, wherein the second copy management table retains a pair status indicating a status of the pair relationship, a restore finish time indicating the time information added to the latest information among time information of each journal data that updated the second volume, and a first validity flag indicating validity of the restore finish time; and wherein the second journal volume management table retains a journal reception time indicating the time information added to the latest time information among time information of each journal data that the second storage system received, and a second validity flag indicating validity of the journal reception time.