If I remember well vfiler unit management through System Manager 2.0R1 is not suported (you cannot add vfiler with the interface in 2.0R1).
In the beta adding vfiler was working really good and we are currently using it (with a config file generated in the beta) in 2.0R1 but we use it for quotas and qtree not for LUN.
I think you can add vfiler manually editing the config file but it's probably not supported, vfiler Management will really be a good new feature for the next version