It’s a shortlist of things that you should probably know when installing VMware NSX-T. Of course, installing NSX-T should be done by following the official documentation. This here is just a few additional points that could help. It’s for your peace of mind afterward.
This is an article from the VMware from Scratch series
NSX Manager is a Cluster of three VMs
You should end up having three NSX-Manager VMs in a cluster when you finish NSX-T installation. The first one will be deployed via .ovf file from vCenter, the other two direct from first NSX Manager GUI as soon as you connect it to vCenter (aka. adding the Fabric -> Compute Manager)
NSX Manager VMs should not run on the same ESXi host
Use vCenter datacenter configuration VM/host rules (affinity rules) to automatically keep manager VMs running on different hosts on the VMware environment. It’s about the host failing and you still having most of the managers running.