Patent ID: 8225059

Claim:
A remote copy system, comprising: a first storage apparatus disposed in a primary site configured to provide to a host computer a first volume to be used for reading and writing data, and periodically or randomly to create a snapshot of the first volume; a second storage apparatus disposed respectively in one or more secondary sites configured to restore a data image of the first volume to a second volume in a self-apparatus based on differential data between the snapshots that are transferred from the first storage apparatus; and a monitoring server configured to control a transfer mode of the differential data to be transferred from the first storage apparatus to the second storage apparatus, wherein the monitoring server: collects resource information representing a resource usage status from the first and second storage apparatuses; decides the transfer mode of the differential data to be transferred from the first storage apparatus to the second storage apparatus based on the collected resource information; and controls the first and second storage apparatuses so as to transfer the differential data from the first storage apparatus to the second storage apparatus according to the decided transfer mode; wherein the monitoring server determines whether an operational purpose of the secondary site is a backup purpose or a mirror site purpose based on the collected resource information, and controls the first and second storage apparatuses so as to transfer the differential data from the first storage apparatus to the second storage apparatus based on a transfer mode according to the operational purpose of the secondary site based on the determination result; and wherein the monitoring server determines the operational purpose of the secondary site based on at least one among an access frequency to the second storage apparatus, number of users permitted to access the second storage apparatus, type of data retained in the first and second storage apparatuses, and usage status of the first storage apparatus which are recognized based on the resource information.