TABLE OF CONTENTS Understanding the interaction between XenVMs and Xen Hosts requires that administrators understand their workloads. Once they understand their workloads for every application, they can decide which XenVMs work well together and which ones will contend for resources.
Once the Xen Hosts are installed, administrators will have to create the XenVMs. Xen provides different techniques for provisioning XenVMs. Users can create a new XenVM by installing from media or network shares, they can clone a XenVM, they can export a XenVM and use it as a template, or they can convert the OS on a physical host to a virtualized XenVM.
As discussed in previous chapters, the appeal of virtualization includes the ability to maximize the utilization of IT assets, reduce administrative overhead, and accelerate provisioning times, among others. At first glance, virtualization is mostly about CPU and memory utilization, but as most of us that have been implementing virtualization technologies for years can attest, both network and disk I/O can also have a major impact in workload combination decisions.
To accomplish an optimal workload mix, thorough research has been done on current physical server utilization and an understanding of the additional horsepower impact of newer servers and I/O subsystems. To help with this task, both commercial and open source products are available that can assist in mapping physical-to-virtual workloads.
Memory is one of the most expensive system components, and one that should not be underestimated. Xen allows administrators to reserve a minimum...
