In the meantime, can someone help me out with installing the right plugin and whatnot in the OMV?
Go to OMV-Extras (wrote to fast) System -> Plugins and install the Nut-plugin,
Re-read the thread (or most of the 1st page) and most pointers are here,
I have to install usbhid-ups driver, right?
The plugin will take care of everything,