Open source solutions for virtualization: Xen and KVM

This is the introduction of a paper called Comparison between open source solutions for paravirtualization and full virtualization: Xen and KVM
Written in October 2013 for Cloud Computing, a subject from the Information Techonology & Management program at IIT, Chicago.
Download the paper here

Virtualization has become increasingly important in the computing industry in the past couple
of decades. The purpose of virtualization is to allow multiple OSs to run in the same machine,
making use of the same hardware but, in most cases, being isolated of one another. This is a
powerful idea with many uses, such us provide an isolated secure development environment for
programmers and testers and replicate the production environment for employee training.
Virtualized OSs are also very easy to duplicate, send, remove or restore.

However, the most relevant use of virtualization is in data centers and big servers. A very
powerful machine can be split in smaller running OSs, making them available for different
purposes and even to different people. This is the use that has made virtualization so popular, as
Internet keeps growing. Probably, its growth will continue exponentially during the next ones.

Virtualization can be achieved using different techniques, each one of them with its advantages
and disadvantages. The choice of which one to use only depends on the system requirements.
For server partitioning, the most adequate are paravirtualization and full virtualization. The
difference is only in implementation details: how the virtualized OSs are managed and how do
they make use of the machine hardware resources. However, since virtualization is getting more
important every day, it’s useful to know them both in order to choose the most appropriate one
and know better how data centers and Internet web servers work.

There are many virtualization solutions, some of them proprietary and some others open source.
With open source projects gaining more popularity, the two most famous open source tools
nowadays are Xen and KVM. While Xen is the best example of paravirtualization solution, KVM
only offers full virtualization. The competition between these two projects has been very
interesting to follow. KVM’s popularity increases despite the fact that it’s less mature than Xen,
which is already implemented by many Internet giants who have invested lots of resources in
this solution.

Download the full paper here