OMV 5 is not ready nor are any of the plugins. Why do you want to try it?
im planning a nas using a hp microserver n54l i have tried the omv 4 but have lots of issues using the usb as boot drive,i have tried too the freenas and xigmanas but the interface of omv is the best so far, then i like to try to use the base functions to make a decision where to start, and i think to have a devel build its i nice way to evaluate the next statement of the system