vSphere HA configuration fails on newly deployed ESXi host

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Newly deployed ESXi host fails to install/configure vSphere HA agent.

• The below errors are seen on the host's summary tab in vSphere client:

  
  

  • "vSphere HA agent for this host has an error: vSphere HA agent cannot be installed or configured."

  • "vSphere HA cannot be configured on this host because there are no mounted datastores."

  • "No datastores have been configured."

Environment

VMware vSphere ESXi 8.x

Cause

• This issue occurs when there are no datastores configured/mounted on the host.

• This issue usually occurs during deployment or rebuild of an ESXi host and the datastores are not 

• vSphere HA uses datastore heartbeating to distinguish between hosts that have failed and hosts that reside on a network partition.

• With datastore heartbeating, vSphere HA can monitor hosts when a management network partition occurs and continue to respond to failures.

Resolution

To resolve this issue:

1. Create and mount a datastore on the affected host.
2. Then, reconfigure HA for the host by vSphere Client > Right-click the affected host from the inventory > Click on "Reconfigure for vSphere HA". Else just disable and re-enable vSphere HA on the cluster.

Additional Information

Other possible issues which can trigger this alert:

• Error: "vSphere HA agent cannot be correctly installed or configured"
• Troubleshoot ESXi heartbeat datastore problems affect vSphere HA