Yes,technically this is certainly possible . If you have Enhanced Linked Mode configuration , overall migration(Movement of VM's as well) process will be easier. The primary NSX Manager runs the controller cluster that means secondary NSX should never have controllers and any overlapping SegmentID pool
I'm sure there is a cross vcenter failover guide which can be used to promote the secondary NSX manager to the primary manager. If I remember correctly, I've run through this failover myself. Although I can't find the documentation, perhaps Sreec will have better luck
This is essentially what you would want to do with your 2 new sites.
Hi, the answer is here "How Cross-vCenter NSX Works". If you change the role of a primary NSX Manager to standalone and any universal objects exist in the NSX environment, the NSX Manager will be assigned the transit role. The universal objects remain, but they cannot be changed, and no other universal objects can be created. You can delete universal objects from the transit role. The transit role should only be used temporarily, for example, when changing which NSX Manager is the primary.
Verify that Segment ID Pool doesn't overlap on each NSX Managers, and Universal Segment ID Pool is the same across the all NSX Managers.
So, steps should be these:
0. Perform a Backup of the all NSX Managers you have deployed into your environment
1. Perform Universal Synchronization (before doing any action)
2. Select the Primary NSX Manager and Remove Primary role (Now all NSX manager change in Transit Mode)
3. Now switch on "NSX Controller Nodes" and clean up (deleting) all the controllers.
4. Then switch back to the tab "NSX Managers" and select the New NSX Manager that you want to become Primary and Assign the Primary Role.
5. Create new Controllers Assigned to the New Primary NSX Manager
6. When correctly deployed.... switch back to the tab "NSX Managers"
7. Select the New Primary NSX Manager and -> Actions -> Add Secondary Manager (Proceed accepting the certificate until the end)
8. Repeat for the others NSX Manager .....
9. Verify that the Communication Channel is healty