Problem. Fresh install of OMV. Downloaded files as part of install with no problem. Once the install in completed, the network connection wouldn't work. I would log into root and get network is unreachable. Did omv-firstaid and rebuilt the network configuration.
This is where the first clue of the issue. When selecting the wireless card, it doesn't ask for a SSID or password. Took a while to figure that out as I assumed it was just using the one from the install. This computer is in the basement and therefore not near a Ethernet connection. Every time it would say that the network connection was successfully configured. A bunch of search... post suggesting ifconfig (doesn't work since OMV doesn't ship with that command). IP Addr works, but didn't show an IP address.
Started digging into the networking and noticed there wasn't a wpa_supplicant.conf.
Added it with the SSID and Password, reboot and boom it works.
The wireless card I used is AC2100.
I couldn't find any google searches with this exact information so I figure I might help out the next guy/gal.