Fixing “Insufficient resources” error in vSphere HA

fixing high availability error

Today, I resolved the error “Insufficient resources to satisfy vSphere HA failover level” in VMware vSphere, a high availability error. The issue occurs when you give a larger virtual machine (VM) a large percentage of the resources available in your least powerful host. The error results in a ugly warning message that appears in your cluster’s Summary tab. The resolution is trivial.

  1. Count the number of hosts you have running:
    • Login to the vSphere client
    • Count the number of hosts in the erring cluster
  2. Edit the cluster settings:
    • Highlight the erred cluster
    • Right-click and select “Edit Settings”
    • Under “Cluster Features”, make certain HA is enabled (checked)
  3. Change the HA settings:
    • Highlight the “vSphere HA” setting (in the list on your left)
    • Select the “Percentage of cluster resources…” radio button
    • Set percentages depending to be approximately 1/hosts where hosts = number of hosts from step (1) above
  4. Save and Validate changes:
    • Click the OK button to save changes
    • Allow the screen to refresh and validate the HA error message is gone

If you need further details about how VMware calculates if a failure can be tolerated, see the following link: http://pubs.vmware.com/vsphere-4-esx-vcenter….