Here is a quick view of the VM configuration I have setup on the Mac Pro:
The image below shows how I have carved the Mac Pro into slots representing Red Hat hosts in this case. If I had chosen to make a more powerful database server I could have sacrificed the standby database VMs and used 2 slots for each primary database node, giving me an oracle database server with 10GB of RAM / 4 CPU. In this case however I wanted to setup the most flexible system … so I only used one slot per server. With this configuration I did over extend the CPU allocation, but since I do not expect high CPU on all my boxes I felt this would be justified. The Host Computer will still have 7GB RAM and all CPU not utilized by Virtual Boxes.