vSphere License key is verified successfully but 'Assign License' does not do anything

Products

• VMware vSphere Standard

Issue/Introduction

Issue occurs after assigning vSphere license key on Standalone host and it shows as 'Assigned Successfully'. However it flips back to Evaluation Mode.

Cause

vSphere Subscription license with Core as the licensing metric when assigned to standalone ESXi Hosts shows as valid and active and when you try to assign the license key, it changes to evaluation.

Resolution

This would be mainly due to license capacity issue.

A minimum of 16 core license is needed to license a processor. 

Verifying the quantity on Host:
Access to Host and click System
Expand the CPU section and review Processor/Socket and Cores per socket.

If the Cores per socket is 16 or less than 16, then you would require 16 Cores per socket.
Multiply the number of sockets and Cores per socket. Total quantity would be the required quantity of vSphere license key to assign it to the Host.

Steps to verify the quantity on Host:
Access to Host and click 'System'.
Expand the CPU section and review Processor/Socket and Cores per socket.

Additional Information

Note - There will be no error indicating that it is less than 16 cores