If the device does not know how to fence nodes based on their uname, you may also need to set the special pcmk_host_map parameter. See man stonithd for details.

If the device does not support the list command, you may also need to set the special pcmk_host_list and/or pcmk_host_check parameters. See man stonithd for details.

If the device does not expect the victim to be specified with the port parameter, you may also need to set the special pcmk_host_argument parameter. See man stonithd for details.

Once the stonith resource is running, you can test it by executing: stonith_admin --reboot nodename. Although you might want to stop the cluster on that machine first.