HA error: "The number of heartbeat datastores for host is 1, which is less than required: 2"

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

While configuring vSphere High Availability (HA), there may be the error:

The number of heartbeat datastores for host is 1, which is less than required: 2

The above error can also occur if one of the two heartbeat datastores go offline due to underlying storage issues.

Environment

VMware vCenter Server 6.5.x
VMware vCenter Server 6.7.x
VMware vCenter Server 7.x
VMware vCenter Server 8.x

Cause

This issue occurs if there is no redundancy in shared storage to allow for datastore heart beats.

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.

Resolution

To resolve this issue:

• Ensure that there are two datastores presented to all hosts in the cluster
• Add a secondary heartbeat datastore. See Configure Heartbeat Datastores 
• Ensure that both the configured datastores are accessible by all hosts in the cluster

Warning: Use the below steps with caution as this will only disable the error, not fix the error. 

 

To disable the HA error message:

1. Log in to vCenter Server.
2. Right-click the cluster, click Settings.
3. Go to Configure tab, under Services click on vSphere Availability.
4. Click Edit vSphere HA in Edit Cluster Settings go to Advanced Options tab.
5. In the Option field type das.ignoreInsufficientHbDatastore, in the Value field type true. Click on ADD and click OK.
6. In vSphere Availability click on Edit for vSphere HA and toggle vSphere HA to disable HA and click OK.
7. Allow time for all the hosts in the cluster to be unconfigure vSphere HA.
8. In vSphere Availability the vSphere HA will be Turned OFF, To Turn ON, Click on Edit vSphere HA.
9. Enable vSphere HA by toggle and click OK. Wait for all the hosts to get vSphere HA configured.
10. Make sure vSphere HA is Turned ON state.