Problem
I was getting the below warning message on my ESXi host for a Virtual Machine (VM).
The configured guest OS (Red Hat Enterprise Linux 6 (64-bit)) for this virtual machine does not match the guest that is currently running (Red Hat Enterprise Linux 7 (64-bit)). You should specify the correct guest OS to allow for guest-specific optimizations.
Solution
Follow the steps given below to change the guest OS version of a virtual machine running on VMware ESXi:
- Log in to the ESXi host
- Select the Virtual Machine and Shutdown the same on which you are getting the above warning message.
- Go to Edit Settings through the Actions menu available as the last icon.
- Go to VM Options tab and expand the General Options
- Select the required guest OS Version, in this case, I have to select the Red Hat Enterprise Linux 7 (64-bit). This option will be disabled if your VM will be started.
- Click on Save button and start your VM.
Now guest OS version of your VM has been changed to Red Hat Enterprise Linux 7 (64-bit)and you will not get any warning message on your ESXi host.
Change guest os version VMware 6.5 greyed out or change guest os version VMware 6.5, if the guest OS version option is greyed out then first you need to shut down your VM.
Last Updated: August 11, 2020