vSphere HA uses datastore heartbeating to check the liveliness of a host if it can't be reached on the management network. This is enabled by default, but we are allowed to choose the datastore that we want to use for heartbeating.
The following procedure explains how to select a datastore for heartbeating:
From the vCenter's Home inventory, navigate to the Hosts and Clusters view.
Select the cluster and navigate to Manage | Settings | vSphere HA, and click on Edit.
On the Edit Cluster Settings window, click on Datastore Heartbeating to expand and view its additional settings:
Choose between the Automatically select datastores accessible from the host, Use datastores only from the specified list, and Use datastores from the specified list and complement automatically if needed options as demonstrated in the following screenshot. In this example, let's choose the third option and manually select the datastores. Click on OK to confirm the selection...