In a case where we had a VM that was a bit sensitive with an application that does not like the ping loss during live migration between hosts in a cluster we wanted to exclude the vm from the automatic dynamic optimization. It might not be totally clear where you find this setting for the VM´s you want to exclude from this load balancing act.

First of all, do you know where you set up automatic dynamic optimization in System Center VMM 2012 R2? For some reason you set it up on the hosts folder and not on the cluster object in VMM:

 

So where do you exclude VM´s from this optimization? If you look under a VM´s properties you can check the actions and there you see the magic checkbox :

And now when the automatic job runs my sensitive VM will stay on the host.