I'd like to archive an existing LXC container that has been configured to run as unprivileged LXC container (see this question).
How can I conserve all the file system meta-data that is used to store the mapped UID and GID for file/folder ownership?
NB: I know that the mapping itself happens on the host, but what I mean is that inside the
userns there are a number of UIDs and GIDs which all map on the host to an unprivileged user, but which in the guest still resolve to different UIDs and GIDs. So whatever that magic sauce is that keeps these things connected at the file system level, I'd like to conserve it in an archive (tar or 7z or similar).