https://forum.proxmox.com/threads/tutorial-mounting-nfs-share-to-an-unprivileged-lxc.138506/
##
##host
sudo nano /etc/fstab
192.212.40.111:/volume1/10-System /mnt/NAS_10-System nfs defaults 0 0
192.212.40.111:/volume2/30-Mail /mnt/NAS_30-Mail nfs defaults 0 0
192.212.40.111:/volume1/70-Photocopie /mnt/NAS_70-Photocopie nfs defaults 0 0
192.212.40.111:/volume1/80-Photo /mnt/NAS_80-Photo nfs defaults 0 0
192.212.40.111:/volume3/90-VideoClub /mnt/NAS_90-VideoClub nfs defaults 0 0
192.212.40.111:/volume3/99-Ftp /mnt/NAS_99-Ftp nfs defaults 0 0
sudo systemctl daemon-reload
sudo mount -a
#host for LXC200
nano /etc/pve/lxc/200.conf
mp0: /mnt/NAS_10-System/docker/VM200,mp=/System
mp1: /mnt/NAS_80-Photo,mp=/Photo
#host for LXC125
nano /etc/pve/lxc/125.conf
mp0: /mnt/NAS_10-System/docker/VM125,mp=/System
mp1: /mnt/NAS_90-VideoClub,mp=/VideoClub
mp2: /mnt/NAS_30-Mail,mp=/Mail
#host for LXC103
nano /etc/pve/lxc/103.conf
mp0: /mnt/NAS_10-System/docker/RASP103,mp=/System
#LXC***
sudo apt update
sudo apt install cifs-utils smbclient nfs-common passwd -y
sudo groupadd -g 10000 lxc_shares
sudo usermod -aG lxc_shares root
sudo usermod -aG lxc_shares david
sudo reboot