Since vSphere 6.5 came along we have deprecated a PSC/SSO topology that I have seen customers deploy quite frequently, therefore I wanted to quickly explain what has changed and why.
Since vSphere 6.5 it is no longer possible to re-point a vCenter server between SSO sites – See VMware KB 2131191
This has a big knock on effect for some customers as traditionally they only deployed a single PSC (Externally) and a single vCenter at each site. In the event of a failure of the PSC at site 1 the vCenter server at site 1 could be re-pointed to the PSC in Site 2. This would then get you back up and running until you recovered the failed PSC.
However in vSphere 6.5 this is no longer possible – If you have two SSO sites lets call them Site 1 and Site 2 you cannot re-point a vCenter server between the two sites. So if you only had a single PSC (think back to the above example and vSphere 6.0) you would not be able to recover that site successfully.
So how do I get round this?
Deploy two PSC’s at site and within the same SSO site/domain (See the below diagram) you don’t even need to use a load balancer, as you can manually re-point your vCenter to the other PSC running at the same site in the event of a failure.
Therefore when deploying multiple SSO sites and PSC’s across physical sites consider the above and make sure you are deploying a supported and recoverable topology.
For a list of supported topologies in vSphere 6.5 and for further reading please see VMware KB 2147672