Is your docker also corrupt after a reboot? (OMV5, Pi4) This might fix it! Cusack Mar 21st 2020 Was having the same issue with normal hdd (no usb) and OMV on PC. Emby in docker/portainer was restarting from scratch like there were no Config folder when rebooting OMV.Your solution fixed the problem.Thanks for sharing.
BTRFS no space left - kernel 5.4 bug Cusack Mar 17th 2020 Thanks HannesJoI was about to let go OMV because I couldn't find a solution for this problem.