What NSX-T Manager appliance size is good for your environment?

NSX-T 2.4 has NSX Manager and NSX Controller still logically separated but physically integrated within a single virtual appliance which can be clustered as a 3-node management/controller cluster. So the first typical question during NSX-T design workshop or before NSX-T implementation is what NSX-T Manager appliance size is good for my environment.

In NSX-T 2.4 documentation (NSX Manager VM System Requirements) are documented following NSX Manager Appliance sizes.

Appliance Size	Memory	vCPU	Disk Space	VM Hardware Version
NSX Manager Extra Small	8 GB	2	200 GB	10 or later
NSX Manager Small VM	16 GB	4	200 GB	10 or later
NSX Manager Medium VM	24 GB	6	200 GB	10 or later
NSX Manager Large VM	48 GB	12	200 GB	10 or later

In the above documentation section is written that

• The NSX Manager Extra Small VM resource requirements apply only to the Cloud Service Manager.
• The NSX Manager Small VM appliance size is suitable for lab and proof-of-concept deployments.

So for NSX-T on-prem production usage, you can use Medium and Large size. But which one? The NSX-T documentation section (NSX Manager VM System Requirements) has no more info to support your design or implementation decision. However, in another part of the documentation (Overview of NSX-T Data Center) is written that

• The NSX Manager Medium appliance is targeted for deployments up to 64 hosts
• The NSX Manager Large appliance for larger-scale environments.

Conclusion

Long story short, only Medium and Large sizes are targeted to On-Prem NSX-T production usage. The Medium size should be used in an environment up to 64 ESXi hosts. For larger environments, the Large size is the way to go.

Hope this helps to your NSX-T Plan, Design, and Implement exercise.