Which license do you use? Is it a fresh ESXi 6.7 host and have you installed a free license for ESXi 6.7 or has the host been upgraded from 6.0 or 6.5? Have you configured VMs with more than 8 vCPUs?
Thanks for the help. To your questions:
1. Currently we are still using a trial version license.
2. The system is of a fresh ESXi 6.7 installation, and not updated from the lower ones. this is the message I got if was to run uname on it :
" VMkernel ... 6.7.0 #1 SMP Release build-8169922 Apr 3 2018 14:48:22 x86_64 x86_64 x86_64 ESXi "
3. This vm was originally created with 16-CPU, and started without any problems. But today, if I was to downsize it to 2-CPU, I still got this failure.
Currently we are still using a trial version license.
You mean the evaluation period of 60 days? And you have never configured a license key?
So, if this is true, you need a free license key which can be downloaded from the VMware website. Without that the virtual machines can't be powered on after this 60-day period.
See here for more information on how to obtain the free license key:
Sorry, I have already done this, and that is the key I am using right now. A side question I have is, this free key does expire. Is there a way to generate a new one, when the old one is gone ?
The free license key has no expiration date.
Is a license key displayed under the menu item "License & Download" when you log in to the my.vmware.com portal? And is this displayed license key the same as the one used for your ESXi host?
The answer is "yes" to both questions. Thanks. -Jack
You can try to remove the license on the ESXi host and then assign it again.
You won't be able to change the VCPU count if the machine is running as the free license does not license the HA module.