Multiple target machines can act together as a unified, coherent distributed system, configured as a cluster. Once ONOS is installed (and runs) on multiple target machines, it’s very easy to form a cluster. From one of the target machines, run:
Form a cluster of three instances, from one of the target machines
/opt/bin/onos-form-cluster $TARGET_MACHINE_1_IP $TARGET_MACHINE_2_IP $TARGET_MACHINE_N_IP
where $TARGET_MACHINE_X_IP is the IP address of the target machines that should form the cluster (including the IP address of the target machine where the commands are run from).