vSphere HA Configuration Fails Post vCenter Patching Due to Stuck vmware-fdm VIB

Products

• VMware vCenter Server

Issue/Introduction

After applying a patch update to the vCenter Server, configuring or reconfiguring vSphere High Availability (HA) fails across multiple ESXi hosts in one or more clusters.

• The vSphere Client tasks for HA configuration fail during the agent installation phase (typically hanging or failing near completion).

• The following error or similar may appear in the vSphere Client:

  "vSphere HA agent cannot be correctly installed or configured"

• Even after vSphere HA has been disabled at the cluster level via the UI, the Fault Domain Manager (vmware-fdm) VIB remains actively installed on the ESXi host. To verify this symptom:

  1. Connect to the affected ESXi host via SSH using root credentials.

  2. Run the following command:

     esxcli software vib list | grep vmware-fdm
     

  3. If the host is impacted, the command will return active version details for the vmware-fdm package, confirming that the automated uninstallation failed.

Environment

vSphere 8.0

Cause

This issue is caused by a packaging or state desynchronization event between the newly patched vCenter Server and the managed ESXi hosts during the upgrade window.

When vSphere HA is disabled at the cluster level to remediate or reset the state, vCenter Server fails to trigger or execute the automated uninstallation of the legacy vmware-fdm agent on the hosts. Because the outdated or corrupted VIB persists in the ESXi packaging database, subsequent tasks to re-enable HA fail. The vCenter automated deployment engine cannot safely overwrite or reconcile the existing FDM installation path.

Resolution

To resolve this issue, you must manually purge the orphaned FDM agent from each affected ESXi host to clear the packaging database before letting vCenter push a fresh copy.

Step 1: Disable vSphere HA at the Cluster Level

1. Log into the vSphere Client.

2. Navigate to the affected cluster in the inventory tree.

3. Select the Configure tab, expand Services, and select vSphere Availability.

4. Click Edit.

5. Toggle vSphere HA to Off and click OK. Wait for the cluster tasks to finish.

Step 2: Manually Remove the vmware-fdm VIB from ESXi Hosts

Perform the following steps on each affected ESXi host within the cluster:

1. Enable and establish an SSH session to the ESXi host using root credentials.

2. Execute the following command to forcefully remove the orphaned FDM agent:

   esxcli software vib remove -n vmware-fdm
   

   Note: A system reboot is not required after removing this VIB.

3. Confirm the VIB has been removed successfully by running the verification check again; it should now return blank:

   esxcli software vib list | grep vmware-fdm
   

Step 3: Re-enable vSphere HA

1. Return to the vSphere Client.

2. Navigate back to your cluster’s vSphere Availability settings (Configure > Services > vSphere Availability).

3. Click Edit, toggle vSphere HA back to On, and click OK.

Result: The vCenter Server's Automated Agent Deployment engine will recognize the host as a clean destination and will successfully push, install, and initialize a fresh, compliant version of the FDM agent across the cluster.