One of the last issues for OMV has been finished today. The UPS plugin enables you to define how to act on power loss, e.g. immediatelly force a shutdown after a given time range (the UPS may come back during this time, so no shutdown is necessary) or if the battery reaches its lower limit. If notification is enabled you’ll get an email for every changed state, also messages will be written to syslog.
You are also able to get various details about your UPS via the WebGUI, e.g battery charge or temperature graphs.