I accept that OMV is a NAS and must obviously use shared folders, otherwise it wouldn't work. My comments were to do with structuring the linux filesystem. OMV contains a tool to mount a filesystem but no tool to create the directory structure inside it or even to view it.
It does offer an ssh service (does ssh require shares?) so that you can use bash, or you can use a share to a different system and use the directory tools from that.
I not trying to be critical. I'm just learning. Presumably you could create a share from / so that the whole of the OMV filesystem was shared. Would that be the best approach?