Ok, so I answered my original questions by YOLOing it. I wanted to backup the OMV SD card onto my laptop, but I ran into the same problem described here unix.stackexchange.com/questio…tecting-sdcard-partitions so I risked my OMV installation to bring you these findings and satisfy my curiosity.
- Adding a network interface in the OMV GUI is necessary to get network statistics to show up in Performance Statistics. Interestingly, the statistics are gathered whether they are displayed or not. By adding my interface, the statistics from months ago appeared. When I removed the interface, network statistics went blank again in Performance Statistics.
- Removing the interface seems to break OMV... I thought I broke my setup, because network activity and pings no longer worked to my OMV machine. I pulled the power plug and replugged it and fortunately it seemed to have saved the interface, which showed up again. Tthe GUI displayed the yellow notice that for changes to take effect I must either Apply or Revert (I had applied when it broke the network). This time I reverted, and all is good.