"In the wise words of Wikipedia, "Virtualisation is a broad term
that refers to the abstraction of computer resources". Within this
definition sits a whole variety of products - Sun's VirtualBox,
Parallels, Bochs, Xen, KVM, Qemu, various flavours of VMware and
many others. And there's a great deal of jargon to confuse the
unwary - emulation, full virtualisation, paravirtualisation,
virtual appliance, hypervisor... the list goes on. And not everyone
agrees exactly what all these terms actually mean.
"We're going to deliberately sidestep the jargon and the hype to
take a practical look at the virtualisation technologies in Ubuntu,
in particular KVM and Qemu and the related userspace tools that
create and manage virtual machines. Although the discussion centres
on Ubuntu, the technology is applicable to all Linux distros.
"Warning: if you're a little less experienced (or a little more
time constrained!) you might find our other article, virtualisation
made easy, a little easier to read.
"The diagram below is an attempt to show how some of the
virtualisation components in Linux relate. The lower part of the
diagram shows the underlying technologies. On the left, Xen is a
software layer that conceptually sits below the operating system.
It's called a hypervisor..."