From time to time we restart the ESXi servers on all ESXi6 host using services.sh restart. What I have noticed is the one two separate occations we received an alert that two VM which are cluster that HA failed to restart them yet when you log onto the guest. The VM's new restarted nor did Windows Failover manager indicate the application failed over. I know when I host disconnects it kicks in the host isolation responce. My question is why only one VM on an affected host that was clusted?