I am trying to create an alert/report indicating realistic capacity depletion. Unfortunately, the default VMware capacity calculation is based on peak VM size and can easily be thrown askew by one oversized VM. The default VMan capacity calculation seems to be similarly affected. For example, I have a cluster with 55% memory utilization and 11% CPU utilization, but VMware HA indicates that I don't have any spare host capacity, and VMan indicates that I have room for 2.5 more average-sized VMs, which strikes me as unrealistic. Is there a way to a) tweak capacity planning assumptions to be a little more realistic and b) alert when a capacity threshold is exceeded based on that calculation? I would ideally like to calculate consumption based on number of hosts in a cluster and have at least one host's worth of resources free, so if anyone has computed something like that, I'd love to hear how.
in capacity planning you can reduce peak VM size in Advanced options -> Calculation Settings by setting Sizing target to 75% percentile. Also if you want to have at least one host marked as free you can set 1 to Failover Capacity in Advanced options -> Calculation Settings.
Hope that would fit your requirements