To enable nesting (containers in an LXC container) one wants to include the /usr/share/lxc/config/nesting.conf in a machine's configuration. Though if, for example, something like an "apparmor" setting is in the config and apparmor is not installed it may require taking the values from the nesting config and placing them directly into the machine's config (mainly want to make sure things like /proc or /sys or /dev are setup properly as more than read-only)

This does have security implications


lxc can do more than directory-based containers (including image files via loop, btrfs, lvm, etc.) during creation.