from the windowing desktop or with X11 forwarding (ssh -XC root@tdvm) you can execute:
that will bring up a graphical set of terminals. in the Supervisor window execute:
this will then start a ferret process on another graphical term. However this is low performance X11 is pretty slow. So I'd just run on an cli with no X11:
then on the Supervisor prompt:
not the window index it has created with ferret eg window 1 then in another terminal session:
then you land on the ferret prompt. sorry it took three years to respond.