How can make a full copy of the contents of a btrfs filesystem? By full copy I mean not only the current data, but also different subvolumes with their snapshots, ideally preserving their CoW structures (i.e.: not duplicating blocks with the same content.
It seems a block-level copy (such as with
dd) is not a good idea, since it duplicates the UUID, and there isn't a way to easily change it, apparently.