Alert The number of vSphere HA heartbeat datastores for this host is 0, which is less than required: 2 observed.

Products

• VMware vSphere ESXi
• VMware vSphere ESXi 7.0
• VMware vSphere ESXi 8.0
• VMware vCenter Server 7.0
• VMware vCenter Server 8.0

Issue/Introduction

The number of vSphere HA heartbeat datastores for this host is 0, which is less than required: 2.
Was observed in the vCenter GUI on a host in an vSphere High Availability enabled cluster.

Environment

vSphere 7

vSphere 8

Cause

This issue occurs if there is no redundancy in shared storage to allow for datastore heart beating. As of vSphere 6.0 and above, vSphere HA requires a minimum of two shared datastores shared between all hosts in a cluster for proper datastore heartbeat detection to function.

1. Log in to vCenter Server.
2. Right-click the cluster and click Settings.
3. Go to Configure tab and under Services and click on vSphere Availability.
4. Expand Datastore for Heartbeating
5. Verify that no datastores are configured

Confirm this by looking at the Heartbeat datastore configuration for the cluster in question and confirm that no datastores have been selected:

Resolution

To resolve this issue, add at least two heartbeat datastore for HA monitoring to the vSphere Availability configuration.

1. Log in to vCenter Server.
2. Right-click the cluster and click Settings.
3. Go to Configure tab and under Services and click on vSphere Availability.
4. Click Edit vSphere HA and in Edit Cluster Settings go to Heartbeat Datastores
5. Pick either Automatically select datastores accessible from the hosts or Use datastores from the specified list and complement automatically if needed
6. If Use datastores from the specified list and complement automatically if needed is selected, then please select at least two datastores from the Available heartbeat datastores list below.

Then confirm the setting change.