virtualbox.org

I have a Mac OS X server Intel Core 2 Duo as my host machine and Ubuntu Server as my guest. I am planning to run applications demanding more than one CPU in the virtual machine. I know CPU allocation can be configured from the VB GUI processor tab or using the VBoxManage command tool, however; I would like to know if there is a way for the host to DYNAMICALLY allocate processors depending on the needs of the guest and if that the case, how can it be monitored?.

Thanks.

What you're looking for is the CPU Hotplug feature. Please read the manual, chapter 9.5, on how to use that feature.