I have two ESXi 5.1 host in a cluster. I just installed a virtual appliance and when I try to start if I get an error saying "Insufficient resources to satisfy configured failover level for vSphere HA." Bot hosts are very low on resources and if I shut down a couple of other VMs I get the the error. What could be the issue?
Note: Discussion successfully moved from VMware vCenter™ to Availability: HA & FT
vSphere HA Admission Control is responsible for this. Check your HA properties in the cluster and see which Admission Control Policy is being used.
What HA Admission Control policy are you using on your Cluster?
Do your VM's and/or the appliance have CPU and/or memory reservation set?
There probably is a reservation set on one of your virtual machine's which skews the outcome of the algorythm used by Admission Control. I have written a dozen articles on this topic. First I would suggest to check for reservations, you can do this very simply by using an awesome tools like RVTools (http://www.robware.net/)
Second, I would suggest reading some of the following blog posts:
http://www.yellow-bricks.com/vmware-high-availability-deepdiv/#HA-admission
http://www.yellow-bricks.com/2012/12/04/insufficient-resources-to-satisfy-ha-failover-level-on-cluster/
Or just do a search on my blog:
http://www.yellow-bricks.com/?s=admission%20control