This sort of approach is no longer useful, IMO. Why would you /want/ a remote /usr? That is to say, when you can even more easily have a remote / (which includes /usr)? This makes no sense in a package-managed environment where / and /usr are a managed whole. Modern systems have so much disc space, that sharing /usr between systems is a historical curiosity only. By all means share the /entire/ rootfs, but /usr separately is not useful.