Right now i'm in the process of moving my OMV3 standalone installation to a virtulized setup. Why you may ask: well I wanted to consolidate various servers I run at home (FHEM home automation, OMV, TVServer) and also reuse the CPU power of my OMV-server as gaming rig.
I have silenced my server quite good so it can reside in the guestroom/office.
Another possible way would have been using 50€ Intel SOCs to drive power consumption of the servers down and built a dedicated gaming PC, however I decided otherwise.
First thing was installing proxmox on an old 2.5" drive. Then I created a VM for OMV and passthroued my system drive and data drives. Everything was running smooth, mergerfs etc. nothing to change.
Then I installed Windows in an KVM and passed trough my 1050TI GPU and voila (ok, after 2 evenings of fiddling with the settings) I could play City Skylines on my main external Screen.
Next steps: Moving the phyical OMV system drive to a disk image.