Valid for all versions

When our client's are working with different host versions it's a known fact they may encounter a few limitations

In all scenarios SynetoOS is going to performe as aspected all the task related to migration and protection.
Therefore the issue might prompt out only when client is trying to start a vm resulted of a migration or a replica in a host with a different ESXi version from the source

Each ESXi release has a Virtual Hardware Version set for, if the involved host's does not share the same version level this guide will help you understand how to proceed to troubleshoot the issue

Symptoms

Most frequent symptoms we encounter are:

• A virtual machine fails to power on.
• Some virtual machine operations are greyed out and unavailable.
• You experience unexpected behaviour in a guest operating system.
• Guest OS may report backing storage as a hard disk as opposed to a solid state drive.
• Impossible to register a VM or it disappears from Virtual Machines panel when it already was registered

How to resolve the incompatibility

First workaround we can propose is to synchronise the ESXi versions using our guides for the costumized upgrade

If upgrade or downgrade is not an option

Follow VMware official solution to change virtual hardware version on the vmx file, or the alternative (in cases where VMware tools is installed) upgrade the VM compatibility from ESXi and Vcenter GUI

Change vmx virtual hardware version

For this operation VM needs to be power off from the beginning

Step 1: Connect to ESXi GUI

Step 2: Find the .vmx file of the VM 

• Find the VM of your interest on the dashboard and go to edit settings 
• Select the VM Options tab and navigate in to General Options
•  Check .vmx path location on the VM config file field.
  In the following example the file is on datastore "free"  under the folder "free"

Step 3: In storage browse the datastore resources

• Go to Datastores dashboard and open Datastore browser

Step 4: Navigate into the .vmx file location

Step 5: Download the .vmx file

• You can download the .vmx file selecting it + right click  or directly from the toolbar options

Step 6: Open .vmx file in a text editor

" Before you alter the virtual machine's files, VMware recommends copying the virtual machine's folder to a safe location (either on an external hard drive or anywhere else on the PC's hard drive) to backup the virtual machine. "

• Confirm VM is power off
• Confirm you saved a copy of the file in a safe location
• Open the file in a text editor ( eg. Sublime Text)

Step 7: Find the virtualHW.version field on the text 

• Look for the virtualHW.version field and identify the number associated
  For the example bellow the version number is 19 

Step 8: Identify the Virtual Hardware Version of your interest

• Now that we have found the current virtual hardware version of the VM you can identify to which version number you need to change the id on the .vmx file
  On the sample scenario the vm currently has 19 = ESXi 7.0 U2, suppose that we would like to change it to the ESXi 6.7 U2 version, we would've modify the number to 15 
• Use the bellow table to identify the Virtual Hardware Version you need

" Changes made to the .vmx file do not take effect until the next time VMware Workstation or VMware Player is opened. 
If the application is currently open, quit it and re-open for the changes to take effect. "

Upgrade VM Compability 

Step 1: Ensure that VMware Tools is installed on the VM and that it is power off

Step 2: Select VM and go to actions

• From the Virtual Machine panel, select the VM and go to actions in order to see the Upgrade VM Compatibility option

Step 3: Select the option that better suites you 

Step 4: Select Upgrade and reboot the VM

The process for Vcenter is the same

VMware Resources:

Locating a hosted virtual machine's files

Editing the .vmx file of a VMware Workstation and VMware Player virtual machine

Virtual machine hardware versions