The definition of virtual Linux is as fluid as the Linux platform itself. For the desktop user, virtual Linux translates into being able to use Linux without changing their existing operating system. For those working with servers however, virtual Linux can mean something very different altogether.
In both instances, virtual Linux is fast becoming a term coined to explain the benefits of using a virtual operating system in place of dedicated hardware.
To the typical desktop user, virtual Linux is a Linux installation that's not actually installed over their existing operating system. These types of Linux instances come in a number of shapes and sizes. Ranging from a LiveCD such as Knoppix down to installations running in what is called a virtual machine. What's the difference?
Virtual Linux running from a LiveCD for instance, translates into the end user being able to connect to the Internet, try out open source applications and browse from their existing Windows installation. All of this is possible without affecting their current operating system whatsoever.
With a virtual machine or "virtualized" installation of Linux, you are basically installing a fully functional install of Linux into a digital container of sorts. This can prove to be helpful for users who want to develop applications for Linux, yet prefer to keep their primary OS as Windows. Why not simply dual-boot? Hassle factor for one thing, along with the ability to leap from program to program with a near seamless feel to it. There is something to be said for running a virtual Linux machine.
There are a number of different ways of looking at what makes up virtual Linux for a server. There's the budget friendly virtual private server (running Linux) that provides users with their own compartmentalized quasi-dedicated server for website use. And then there is a true virtual server in which you have a load balancer that distributes calls to the virtual server by splitting up the load to a number of "real" servers.
The first example above is much like a virtualized installation of desktop Linux. The defining difference is that it's designed to emulate a full-blown server, rather than simply catering to the needs of a single desktop user. This has been known to provide cost savings in various ways.
There seems to be a common misconception that there is a definitive term known simply as virtual Linux. The fact of the matter is that there is only "Linux." Beyond that its a matter of how it's being implemented at that time.
However, the generally agreed upon definition for virtual Linux seems to be best summed up as follows:
Virtualization means many things to many people. A big focus of virtualization currently is server virtualization, or the hosting of multiple independent operating systems on a single host computer.
To many enterprise ventures using Linux, the concept of virtual Linux is basically the shortening of Linux Virtualization. This then splits off as virtualization for the desktop for home users and server virtualization for the enterprise.
According to this level of understanding, there is no de facto "virtual Linux," rather different ways of virtualizing instances of the Linux platform for enterprise use. Many will disagree with this belief, and there is certainly room for debate on the matter.
Despite the success seen with the Ubuntu Linux desktop distribution, the real revenue flows from the Linux server niche economy. Technologies such as KVM and Xen reflect the efforts by those in the enterprise to make virtual Linux something that largely maintains an enterprise focus.
Thanks to the technologies highlighted here, we are now able to provide near native speed, in part due to advances with features like virtualization and paravirtualization. Both concepts provide the kind of performance that have businesses spending less on hardware resources, freeing them instead to invest their funds elsewhere.
These advances, bundled with the need from the enterprise world, have created a market in which virtual Linux has managed to find a permanent home in the world of servers and the Enterprise Linux realm.
On the desktop front, virtual Linux is seeing the bulk of its development taking place in the form of virtualized desktop environments using thin clients. This is becoming increasingly popular instead of relying on full stand alone workstation, from a cost perspective.
While home users are inclined to embrace localized virtualization and liveCDs, the enterprise user is once again the driving force for how virtual Linux evolves on the desktop. Thus far, it appears to be again coming full circle back to servers, providing thin clients access to the desktop environment. In short, thin clients supported by virtualization with servers is virtual Linuxs sweet spot for growth.
Some industry observers are looking to Google's Chrome OS to eventually become a network computing environment in which everyone will use a thin client to connect to a Google mother-server. Yet this outcome is far from guaranteed.
Early indications show us Google is eyeballing netbooks and have no real interest in tackling virtual Linux on the desktop as described above. So the idea of seeing Google getting behind a home user virtual Linux option is extremely unlikely right now. Maybe this will change in the future, but for the time being it's utter nonsense.
The future of what we refer to as virtual Linux will remain server based, with some progress being made in the realm of local virtualization thanks to efforts on the desktop as well. And in the years to come, I see the overall vision of what we perceive as virtual Linux largely remaining unchanged. Virtual linux is, after all, Linux extended further to meet the needs of the common user. It's not a stand alone product.