US Patent 7636822 Method of checking the topology of remote copy

Provided is a computer system management method capable of preventing a loop of pairs from being formed upon remote copy pair formation. The method of controlling formation of a remote copy pair of logical volumes in a computer system including a plurality of logical volumes includes: receiving a request to form a remote copy pair; judging whether or not a loop of remote copy pairs will be formed by executing the requested remote copy pair formation; and executing the requested remote copy pair formation when it is judged that no loop of copy pairs will be formed.