Patent ID: 7636822

Claim:
A method of controlling formation of a remote copy pair of logical volumes in a computer system comprising a plurality of storage systems including a plurality of logical volumes and a plurality of computers, each storage system being coupled to one of the computers, the method comprising: receiving a request to form a remote copy pair; judging whether or not said request is sent from one of said plurality of computers, judging whether or not a loop of remote copy pairs will be formed by executing the requested remote copy pair formation based on connection information to identify copy source and copy target logical volumes and storage systems of existing remote copy pairs that have been formed in the computer system; and executing the requested remote copy pair formation when it is judged that no loop of copy pairs will be formed, wherein each storage system of the plurality of storage systems includes at least one logical volume and the connection information, and wherein the connection information is consulted to find, from among the existing remote copy pairs, one that has, as its copy source logical volume, a copy target logical volume of the remote copy pair requested to be formed, or a logical volume that is below the copy target logical volume and, when such an existing remote copy pair is not found, it is judged that no loop of remote copy pairs will be formed.