If you deploy Nested ESX and wish to use it beyond the default 90 day evaluation, you will need to license the ESX host, just like you would with a physical host.
Whether you create your own Nested ESX VM or simply deploy the the Nested ESX Virtual Appliance, make sure the cores per CPU configuration on the VM is correct or you may need a much larger CPU entitlement than what you had expected.
The default behavior of vSphere when you create a VM is to automatically manage the CPU topology (cores per CPU) when the VM is powered on for optimal GuestOS and Application consumption.
However, this automatic assignment or even a manual assignment could have some unexpected consequences when it comes to ESX licensing ...
Let's use a concrete example, say you want to configure your Nested ESX Host to have 32 CPU Cores, which of the following would give you that outcome?
Technically, both will give you 32 Cores ...
- In the first screenshot, you will end up with 32 CPUs and each CPU will contain a single CPU Core
- In the second screenshot, you will end up with 1 CPU and single CPU will contain 32 CPU Cores
However, when it comes to ESX licensing, this is where it will matter between the two scenarios.
- In the first scenario, you will need 512 Core Licenses
- In the second scenario, you will need 32 Core Licenses
If you want to optimize for ESX licensing, make sure that your cores per socket is equal to the total number of vCPUs (e.g. 32 vCPU = 32 cores per socket) and here are the two options to apply the setting:
- vSphere UI - Edit VM and navigate to VM Options->CPU Topology->Cores per Socket
- vSphere API - Using PowerCLI, ensure both -NumCpu and -CoresPerSocket is configured with the same value
Thanks for the comment!