P.t. this is running plain mail - no collab or video.

I want to extend with collab and video, but it is my understanding, that this requires 3 nodes, mail, collab and video.

I have established a test setup with 3 nodes, where collab and video with recording works fine.

But if I try to add the collab and video ui modules on my single-node server, I get awful error messages from dpkg. And I had to go back to a snapshot loosing some mails.
Due to this panic rollback I have unfortunately no log of the error messages.

Question 1: Is there a field-proven procedure for going from single-node to multi-node?

Question 2: Is there a field proven procedure for "migrating" from a running single-node system to a newly installed multi-node system?

Thank you in advance for all help, ideas, info and facts.