Activate Metro Cluster Fault Tolerance

In vSphere 8.0 U3 you can activate Metro Cluster Fault Tolerance in the Fault Tolerance wizard.

In the fault tolerance wizard, you can select a checkbox labeled Enable Metro Cluster Fault Tolerance to activate FT Metro Cluster functionality and a drop-down list for choosing a HostGroup as the preferred location of FT VM. By default, the checkbox is unchecked and the drop-down list is deactivated, indicating that FT Metor Cluster is deactivated for the VM (ConfigInfo.metroFtEnabed is 'FALSE').

When the checkbox is checked, the drop-down list will be activated for choosing a HostGroup. The wizard will prevent proceeding to the next step if no HostGroup is selected for the VM. To ensure the legality of the selected HostGroup, the wizard will call the function queryFaultToleranceCompatibleHosts and retrieve the result through the returned messages.

Before checking the checkbox Enable Metro Cluster Fault Tolerance, the drop-down list of HostGroup is deactivated. A signpost button will be added next to the label Host Group, the signpost content is: Based on the selected Host Group, FT can divide the hosts in the cluster into two groups and ensure to place FT primary and FT secondary in different groups.

After checking the checkbox Enable Metro Cluster Fault Tolerance, the drop-down list is activated in the wizard for the HostGroup selection. FT handles the validation check for the FT Metro Cluster flag and HostGroup, which is triggered by clicking the NEXT button. The wizard sets FaultToleranceConfigSpec.metroFtEnabled to TRUE and FaultToleranceConfigSpec.preferredLocation to the selected HostGroup. Then, the wizard fetchs the compatible host list.

After checking the checkbox Enable Metro Cluster Fault Tolerance, but not selecting any HostGroup, the wizard can't be moved forward with NEXT button with the error message: Please assign a host group for Fault Tolerance VM before enabling Metro Cluster. FT also checks the HostGroup for FT Metro Cluster activated VM and the task might fail if the HostGroup is not configured.

You can remove the configured host group while FT VM is running. FT Metro Cluster is deactivated in such case. However, the host group name is still displayed on the FT information card, since FT Metro Cluster can be re-activated after configuring the host group again.

If you delete the HostGroup for a running FT VM, the FT Metro Cluster is deactivated. In case of a failover, Metro Cluster status Not Applicable Host Group is missing. is displayed on the FT information card. However, if you add the HostGroup back, the FT Metro Cluster will be activated again.

If you delete the HostGroup for a powered-off FT VM, the Fault Tolerance Secondary VM cannot be powered-on.