When shifting the condition of a pair of a main volume and a sub-volume from a split condition to a pair condition according to a request from a user, an information processing unit which can access the sub-volume is inquired whether it mounts the sub-volume or not. As a result, if a managing computer...http://www.google.de/patents/US7225294?utm_source=gb-gplus-sharePatent US7225294 - Storage system control method, storage system, information processing system, managing computer and program
