I was going over some of the VMTN threads and I noticed an issue brought up with Admission Control a while ago. Completely forgot about it until it was brought up again internally. With vSphere 6.5 and vSphere HA there seems to be a problem with some Admission Control Policies. When you for instance have selected the Percentage Based Admission Control Policy and you have a low number of hosts, you could receive the following error
Insufficient configured resources to satisfy the desired vSphere HA failover level on the cluster …
I managed to reproduce this in my lab, and this is what it looks like in the UI:
It seems to happen when there’s a minor difference in resources between the host, but I am not 100% certain about it. I am trying to figure out internally if it is a known issue or not, and will come back to this when I know in which patch it will be solved and/or if it is indeed a known issue.