I have a use-case where I have some Host Folders that is actually an NFS Mount (could also be CIFS/SSHFS/...).
I then bind-mount (bind or rbind) inside the LXC Container in the Form of
lxc.mount.entry: /mnt/<container_name> data/ none rbind,create=dir 0 0
I devised my own little Script (NOT...
