[Pacemaker] Location based on resource utilization

[agutxi Agustin]

Hi list,
I'm new to pacemaker (though I've fought my battles with former
heartbeat), so please don't go harsh on me ;D
I have read through all the documentation I found in the internet for
corosync/pacemaker/ras and have done and tested a few lab scenarios to
build up my knowledge, but in this case, I couldn't figure it out and
Google sent me over and over to the same posts, so I decided to ask
for some clues

Im planning a pacemaker design based on resource utilization.
I want to have a number of light VMs running on top of a few phisical
machines (PMs from now on).
Ideally, every PM will be able to run n VMs, but will be running n-1,
so the load will be distributed among the nodes instead of overloading
one if all are available, and fall back to other nodes if one PM
fails,

I have found no way to find the number of resources (same type, or
even global) running on a node and use that in a rule for location
constraint.
Is this possible?
another way to do this would be to update some cluster nodes
properties in the Resource Agents operations code. Is this an accepted
and proper behaviour or is there a reason to avoid it?

Thank you for your time,
agutxi @






--
"Human beings make life so interesting. Do you know, that in a
universe so full of wonders, they have managed to invent boredom."
Terry Pratchet - Hogfather