Alarm "vSphere HA virtual machine failover failed" occurred

Products

• VMware vSphere ESXi

Issue/Introduction

• Virtual machine status is "disconnected" due to failover failure with the following error on vSphere Client :
  vSphere HA failover operation in progress in cluster #### in datacenter Datacenter: 0 VMs being restarted, 1 VMs waiting for a retry, 0 VMs waiting for resources, 0 inaccessible vSAN VMs
  
  
• In the /var/log/fdm.log file, entries similar to the following are observed :
  YYYY-MM-DDTHH:MM:ss.SSSZ [#### verbose 'Placement' opID=####] [PlacementManagerImpl::HandleNotPlacedVms] Reset Vm /vmfs/volumes/####/vm/vm.vmx, vim.fault.NoCompatibleHost

Environment

VMware vSphere ESXi 8.0
VMware vSphere ESXi 7.0

Cause

A VM-Host affinity rule is configured with the specific requirement "Must run on hosts in group". vSphere HA respects these mandatory rules.
Due to this rule, Primary HA ESXi host cannot find a compatible ESXi host for the virtual machine when the ESXi host fails, preventing a successful failover.

Resolution

To resolve this issue, perform one of the following options: 

　Option 1. Relax the Affinity rule
      Change the VM-Host affinity rule from "Must run on hosts in group" to "Should run on hosts in group" (Soft Affinity). 
      This allows vSphere HA to violate the rule if the preferred hosts are unavailable.

　Option 2. Expand the Host Group
      Add additional healthy ESXi hosts to the Host Group associated with the mandatory affinity rule. 
      This ensures there are available resources satisfying the "Must" condition during a failure.

Additional Information

vSphere HA and DRS Affinity Rules