In Proxmox add this to /etc/pve/lxc/container_number.conf (mount.entry was added for openvpn)

unprivileged: 1
lxc.mount.entry: /dev/net dev/net none bind,create=dir
lxc.idmap = u 0 100000 65536
lxc.idmap = g 0 100000 65536

apt install python3-pylibacl

Python3 script

Make sure the 2nd argument is correct, which is offset from current values in lxc rootfs i.e. if the owner is 200000 executing the script below will set owner to 300000:

  ./change_perms.py /rpool/data/subvol-103-disk-1/ 100000

Adapt /etc/pve/lxc/container_number.conf and /etc/subuid and /etc/subgid accordingly.

• Change ulimits on unprivileged containers
• Create container
• Moving lxc containers
• lxc troubleshooting

• http://tbrink.science/blog/2017/06/20/converting-privileged-lxc-containers-to-unprivileged-containers/ (NOTE:id_map is deprecated)