We've been using vSphere for a long time and this is the first instance where we have looked in to using resource pools to manage cluster resources. What we are trying to do is pool funds from several different groups into a hardware purchase, then split computing resources amongst those groups equally but allow others to grow beyond what their guaranteed fair share if the resources aren't in use by other groups. And if other groups begin to need those resources back, we want vSphere to give back the "lended" resources seamlessly without causing any VM power on issues etc.
I'm fairly sure resource pools set with reservations equal to a specific group's allotment is the way to go here. As I understand, resource pool reservations do not behave like VM reservations and even if I were to collectively reserve 100% of the cluster resources across all of the pools, one resource pool could still grow beyond it's reservation as long as there was no contention. When contention does start, extra resources given to a resource pool will be taken away, but only down to it's guaranteed reservation.
Is my understanding of this all correct? Is there anything I am overlooking that may cause issues, or a better way of accomplishing this task? Thanks in advance.