A system and method for linking external storage systems that includes creating a virtual volume mapping at one or more storage systems. Each virtual volume mapping at each storage system associating a virtual storage volume with a physical storage volume and/or one second virtual storage volume at one or more second storage systems. An access request is received at a first storage system specifying a virtual volume. It is determined on which storage system a physical storage volume associated with the specified virtual volume in the access request is located using the virtual volume mapping at the first storage system and/or the virtual volume mapping at one or more second storage systems. Access is provided to the physical storage volume based on which storage system the physical storage volume is located. Useful in Storage Area Networks and many configurations including 1 to 1, dual path, mirrored, and concatenated, etc.