What is your current setup? Do you have VMAN Appliance (Linux VMAN) integrated with Orion? or do you have only standalone VMAN Appliance with 2 federated collectors?
Main new feature in VIM 8 is that you don't need VMAN appliance anymore (= integration appliance with Orion), because VIM (VMAN in Orion) is now able to poll everything like VMAN Appliance, so you don't need linux VMAN appliance anymore.
VIM 8 has to be installed/upgraded on main poller, but to distribute utilization you could deploy some free pollers. These free pollers will be polling data and just sending results to main.
There is new Migration wizard in VIM 8, that will migrate all your data-sources automatically from VMAN Appliance to your Orion, so you don't have to do it alone, one by one. You don't need internet connection for this, but connection between VMAN Appliance and Orion is needed (but if you have integration working now, connection is allowed)
Thank you P.Darila. That makes things clearer. We are currently running the appliance but being able to integrate it onto the poller would make things simpler although I am a little concerned about resources so will look into adding a free pollers to take some of the strain.