If you have the network modules for your APC Smart-UPS then you can use the embedded soft to perform a smart shutdown. However this method permits you to shutdown all virtual machines and the virtual host with a single serial cable attached to a physical server
– Connect the APC UPS to a non virtualized machine
– Install PowerChute
– Install XenCenter
– Create a default.cmd file (attached) which points to a batch file in the XenCenter directory
– Create a shutdown.bat file (attached) which shutdowns appropriate services, and then shuts down the xen servers, then the host.
– In the PowerChute console, configure it to run the default.cmd file on the power event