Part I Introduction

Virtualization is a technology that provides a way for a machine (Host) to run another operating system (guest virtual machines) on top of the host operating system.

This chapter introduces and explains the components and technologies you need to understand to set up and manage a Xen-based virtualization environment.

Linux containers are a lightweight virtualization method to run multiple virtual units (“containers”) simultaneously on a single host. This is similar to the chroot environment. Containers are isolated with kernel Control Groups (cgroups) and kernel Namespaces.

libvirt is a library that provides a common API for managing popular virtualization solutions, among them KVM, LXC, and Xen. The library provides a normalized management API for these virtualization solutions, allowing a stable, cross-hypervisor interface for higher-level management tools. The library also provides APIs for management of virtual networks and storage on the VM Host Server. The configuration of each VM Guest is stored in an XML file.

With libvirt you can also manage your VM Guests remotely. It supports TLS encryption, x509 certificates and authentication with SASL. This enables managing VM Host Servers centrally from a single workstation, alleviating the need to access each VM Host Server individually.

Using the libvirt-based tools is the recommended way of managing VM Guests. Interoperability between libvirt and libvirt-based applications has been tested and is an essential part of SUSE's support stance.

None of the virtualization tools is installed by default.

Supported virtualization limits for Xen and KVM are outlined in the Release Notes.