You should now be comfortable with creating and managing guest images, including using different types of images as well as distributing different devices and resources to the guests. In this chapter, we cover some of the more advanced aspects of guest resource management. First we present tools for acquiring information that will be useful for assessing how resources are currently shared among guests. Then we move onto guest memory management, VCPU management including the VCPU scheduler, and finally end with IO schedulers. We include a discussion of Xen guest isolation characteristics, paying particular attention to handling of severe resource consumption in one guest so that other guests remain stable.