It's been about a year since I installed a first 2010 HUB server alongside a 2003 installation (clean installs since then!). Would rather look stupid and ask a stupid question, than not be prepared!
When installing the first HUB server, it creates the routing group connector. I cannot remember if this stops any services on the 2003 side or not and this affects whether it is out of hours. The schema extension is already complete and the ExPDA is clean and I am just trying to cover all bases backup wise.
Would a backup of the domain and Ex2003 be required before installing 2010 on the first hub, or is the only thing that can literally be affected just be the 2010 base server due to the fact the account installing it will not be a schema admin as the schema is already complete? Sorry for the silly question!