processors to segment its marketing across various price points. Also, with
some motherboards, the extension is not enabled by default but must be
enabled in the BIOS before it becomes available.
Following closely behind, in May 2006 AMD released virtualization
extensions for its processors. Called AMD-V, these extensions are available
on many of AMD’s processors but not all of them, as this is a higher-end
feature.
A related topic deserves a quick mention here. In the cloud, the idea of
containers has become quite popular. If you are interested in virtualization for
use in cloud computing, read the coverage of containers in Chapter 31,
“Ubuntu in the Cloud,” before you make any decisions.
KVM
Kernel-based Virtual Machine (KVM) is a part of the Linux kernel. The KVM
does not perform hardware emulation but only provides the lower-level tasks.
It needs a second layer to run in user space. This is much faster than running
the entire virtualization process in user space, on top of another operating
system. KVM is designed for use on processors that have either the VT-x or
AMD-V extension enabled. Managing VMs with KVM in Ubuntu is
accomplished using libvirt and QEMU. You can check whether a system
has the extensions enabled by installing and running the kvm-ok package. It
is a simple command-line tool that exits with output 0 if the system is suitable
or non- 0 if not.
Start by installing the following packages from the Ubuntu software
repositories:
qemu-kvm—The necessary user-space component of KVM
libvirt-bin—A binary of a C toolkit to interact with the
virtualization capabilities of Linux that currently supports not only KVM
but also Xen, VirtualBox, and more
virtinst—A set of command-line tools for creating VMs
bridge-utils—A set of utilities for configuring Ethernet connections
in LinuxYou might want to add virt-viewer, which provides a nice GUI and VNC
interface to VMs, and virt-manager, which provides a nice GUI for
managing VMs. If installed, you can find both in the Dash listing of
applications.