TABLE OF CONTENTS This book will give an in-depth account of Xen, Microsoft Virtual Server, and VMware. Before we begin, we will take an agnostic look at the different types of server virtualization and other virtual machine software available.
Virtualization software that presents a virtual set of hardware to a guest operating system makes up the majority of server virtualization products available. These virtualization products provide a VMM that either partially or fully virtualizes the underlying hardware, allowing both modified and unmodified guests to run in a safe and isolated fashion.
The most popular of these products, especially for the enterprise, are VMware, Microsoft, and Xen, in order of commercial market share. VMware and Xen are the most mature of the group, offering the richest set of features, such as live migration and bare-metal installation and execution of the hypervisor, as well as the widest array of supported guest operating systems.
Operating system-level virtualization software is either included as part of an operating system, such as Solaris containers, or is installed on top of an operating system, such as Virtuozzo and OpenVZ. These products present an operating system environment that is fully or partially isolated from the host operating system, allowing for safe application execution at native speeds.
| Note | The key differentiator with operating system-level virtualization software is that, unlike hardware virtualization software, no virtual hardware environment is presented to guests. |
In a few ways, operating system-level virtualization software products provide some advantages over hardware virtualization...
