To use legacy Fault Tolerance, you must configure an advanced option for the virtual machine.
Legacy FT can be used only with single vCPU virtual machines that are not already using FT. To enable legacy FT for each VM that is to use it, you must set the vm.uselegacyft advanced option to a value of true.
- In the vSphere Web Client, browse to the virtual machine.
- Right-click the virtual machine and select Edit Settings.
- Click the VM Options tab.
- Open the Advanced section and next to Configuration Parameters, click Edit Configuration.
- Click Add Row and enter vm.uselegacyft for Name and true for Value.
- Click OK.
Legacy FT is now enabled for that virtual machine.