The vSphere client lists an alert stating, "Insufficient HA failover resources" or "Insufficient resources to satisfy vSphere HA failover level on cluster <Cluster_name> in <Datacenter_name>"

Products

• VMware vCenter Server

Issue/Introduction

After vSphere HA has been enabled on a cluster, the following alerts are seen in the vSphere client:

• Insufficient HA failover resources
• Insufficient resources to satisfy vSphere HA failover level on cluster <Cluster_name> in <Datacenter_name>

Environment

• vSphere vCenter 7.x
• vSphere vCenter 8.x

Cause

"Insufficient vSphere HA failover resources" alerts can be caused by the following:

• Admission Control configuration within vSphere HA
• Resource reservations on VMs in the cluster
• Cluster contains only 2 hosts, 3 hosts must be available for successful Admission Control vSphere HA Admission Control Tech Doc

Resolution

In order to avoid a scenario where a cluster has insufficient resources to satisfy vSphere HA, determine a host toleration failure amount for the cluster, and plan the environment to have enough hosts available to satisfy the resource demand on the cluster when one or more hosts have failed.

Additional Information

To suppress the insufficient resources alerts, Admission Control in vSphere HA can be disabled:

1. Log in to the vSphere Client and navigate to the target vSphere HA cluster in the inventory.

2. Select the Configure tab.

3. Under the Services section, select vSphere Availability and click Edit.

4. Select the Admission Control pane to expose the failover configuration parameters.

5. Locate the Define host failover capacity by drop-down menu.

6. Select the Disabled option to deactivate admission control enforcement.

7. Click OK to commit the cluster configuration state.