In the storage system, a storage apparatus includes a disk device for storing write data from a host computer as a primary volume and copied data of write data as a secondary volume, and a disk controller for collecting and managing status information of a plurality of copy pairs from the disk device with a primary volume and a secondary volume as a single copy pair. The disk controller monitors the status information of the plurality of copy pairs according to the status of failure, and, upon receiving a status notification command, transfers the detailed information concerning a copy pair as the status information of the copy pair subject to a failure, and flag information showing the overall status of all other copy pairs as status information of such other copy pairs.