You can turn on vSphere Fault Tolerance through the vSphere Client.
Connect vSphere Client to vCenter Server using an account with cluster administrator permissions.
The option to turn on Fault Tolerance is unavailable (dimmed) if any of these conditions apply:
- The virtual machine resides on a host that does not have a license for the feature.
- The virtual machine resides on a host that is in maintenance mode or standby mode.
- The virtual machine is disconnected or orphaned (its .vmx file cannot be accessed).
- The user does not have permission to turn the feature on.
- In the vSphere Client, browse to the virtual machine for which you want to turn on Fault Tolerance.
- Right-click the virtual machine and select .
- Click Yes.
- Select a datastore on which to place the Secondary VM configuration files. Then click Next.
- Select a host on which to place the Secondary VM. Then click Next.
- Review your selections and then click Finish.