Open Source Virtualization with Virtualbox

Virtualbox's new version 1.6 is released

If you've been searching for an inexpensive virtualization solution for your laptop or desktop, here's a free, open source solution. Recently purchased by SUN, Virtualbox is an open source virtualization solution for the x86 hardware platform. Though it purports enterprise capability, my experience so far has been in using it as a desktop alternative to VMware Workstation which has a list price of $189.00. I have tested on Ubuntu 7.10 and Windows XP host OS with CentOS (RHEL4), Fedora Core 6, Windows XP SP2, Windows 2000 and Ubuntu 7.10 desktop as guests, all with great performance. My favorite features are the "seamless" mode with the ability to scroll my cursor to the guest OS screen and shared folders, allowing me to share host folders as a network share to the guest OS.

Virtualbox has binaries for Windows, Linux, Mac and OpenSolaris host operating systems and runs a rich list of tested Guest Operating Systems including Windows 98 thru Vista, most Linux versions and even OS/2 and ReactOS support. Touting a modular development methodology and full SDK for developing additions, Virtualbox offers not only the base functionality found in other very expensive solutions, but also has features not present in some more popular virtualization platforms such as the following list from the Virtualbox site:

* Virtual machine descriptions in XML. The configuration settings of virtual machines are stored entirely in XML and are independent of the local machines. Virtual machine definitions can therefore easily be ported to other computers.

* Guest Additions for Windows and Linux. VirtualBox has special software that can be installed inside Windows and Linux virtual machines to improve performance and make integration much more seamless. Among the features provided by these Guest Additions are mouse pointer integration and arbitrary screen solutions (e.g. by resizing the guest window).

* Shared folders. Like many other virtualization solutions, for easy data exchange between hosts and guests, VirtualBox allows for declaring certain host directories as "shared folders", which can then be accessed from within virtual machines.

A number of extra features are available with the full VirtualBox release only (see the "Editions" page for details):

* Virtual USB Controllers. VirtualBox implements a virtual USB controller and allows you to connect arbitrary USB devices to your virtual machines without having to install device specific drivers on the host.

* Remote Desktop Protocol. Unlike any other virtualization software, VirtualBox fully supports the standard Remote Desktop Protocol (RDP). A virtual machine can act as an RDP server, allowing you to "run" the virtual machine remotely on some thin client that merely displays the RDP data.

* USB over RDP. With this unique feature, a virtual machine that acts as an RDP server can still access arbitrary USB devices that are connected on the RDP client. This way, a powerful server machine can virtualize a lot of thin clients that merely need to display RDP data and have USB devices plugged in.

Whereas Virtualbox, also known on the SUN website as xVM Virtualbox, competes in the space with VMware Server, VMware's free version of their platform that requires an underlying operating system much like Virtualbox, SUN has also launched a hypervisor-based product in xVM Server as well as xVM Ops Center for managing virtual machine images.

VMware has a pronounced advantage over SUN in this space with VMotion technology that allows running virtual machines to be moved between physical hardware with no down time, as well as support for a wider range of guest operating systems. I'm told that xVM will have vMotion-like capabilities soon, but I've seen no announcements.

Watch for SUN to make a big play in the consolidated desktop virtualization space, with their Virtual Desktop connection broker software. Vendors in this space see the desktop as the next great virtualization frontier and SUN is in the hunt. On top of that SUN has a partnership in place with Microsoft to grant interoperability and high performance for Windows virtual machines.

SUN's competitors in the virtualization race on x86 are VMware, Microsoft, Virtual Iron, Novell, Red Hat, Citrix and Parallels.