Methods, apparatus and computer program products implement embodiments of the present invention that include ascertaining, by a first storage system, a respective port identifier for each of one or more host ports defined to the first storage system for a logical volume stored on a second storage system. Examples of the port identifiers include WWPN and iSCSI iQN identifiers. A respective unique identifier is assigned to each of the ascertained one or more host ports, and for each of the one or more host ports, the respective port identifier and the assigned respective unique identifier are conveyed to the second storage system. Upon receiving, from one of the one or more host ports, an input/output (I/O) request for the logical volume, I/O request with the respective unique identifier of the one of the one or more host ports is conveyed to the second storage system.