If you look at the backup module, there is a file emoncms-export.sh. You will need to modify the config file to suit, but this should run from the command line.
I have an emoncms container running on Proxmox installed using the emonscripts and an Ubuntu Container (rather than a full VM). This then adds all the additional modules like backup as well. Note, the best way to do it is create a Pi user on Ubuntu.
Works great, Much better that ESXi.