Virtualization Is Not a
"One Size Fits All" Solution"> When it comes to virtual access, there are no "one size fits all" solutions. Virtual application environments enable specially written applications to be more robust while being unaware of its underlying operating platform.An example of this is software written with the open-source Globus Toolkit. These programs, unlike those written simply to use the resources of a cluster, can find available resources when needed over the grid. Virtual processing is the kind of virtual software that most people think of when they hear the word virtualization. However, even within virtual processing, there are really two very different kinds of software. Virtual machines are the most common. These make a single system appear to be many computers, and "single-system image clustering software, which makes many systems appear to be a single computing resource running a single operating environment," observed Kusnetzky. On desktops, the first kind is often useful for developers. It helps desk workers and people who need to run an application that doesnt run natively on their operating system. Programs like VMWare and Microsofts Virtual PC are well known add-ons which enable x86 and Mac respectively to run several operating systems at once. Other programs, like Xen are adding virtual machine capability to native operating systems. Even hardware vendors like Intel Corp. are getting into the act. That said, multiple images of operating systems running on a single powerful computer has long been one of IBMs tricks in the trade. IBM was already making a billion dollars from Linux in 2003. The bulk of that revenue, as it is today, came from running Linux instances on IBM zSeries mainframes. By enabling its powerful mainframe and midrange computers to work as multiple Linux servers, IBM has turned what was once considered old iron into profit. Click here to read about Zens paravirtualization. As William Zeitler, senior vice president and group executive for IBMs STG (Systems and Technology Group) said, while announcing a new IBM mainframe line, the Z9 in July, "The reason the mainframes have grown over the last four or five years is their ability to run new workloads [like Linux]." Specifically, the ability to run Linux as virtual machinesLPARs (logical partitions) in IBM jargonhas driven IBMs sales. Virtual storage is another old concept thats getting a lot more attention. By abstracting away the need to know the actual location of data and programs, implementing SAN (storage area networks) and NAS (network attached storage) to add storage becomes much easier. Examples of this kind of software include IBMs SAN Volume Controller, Hitachi Data Systems TagmaStore Universal Storage platform, and EMC Invista. Unlike the other types of virtualization, virtual storage really tries to accomplish the same goal across its vendors and technologies: provide more storage without requiring application designers or system administrators to worry about the details of physical media or file systems. Finally, just to keep things complicated, there are kinds of virtual programs that dont fit neatly into any of these categories. For instance, theres DataSynapse Inc.s FabricServer. Here, the idea is to virtualize transactional applications within a grid environment. These applications can be running on J2SE, J2EE or .Net. FabricServer shields users from the nitty gritty of using several different applications by providing them with a common interface and the middleware to bind users and applications together. Can this technology hodgepodge we call virtualization help you in 2006? The answer is indeed yes. But, one cannot understate the need to look carefully at exactly what it is youre buying into. Weve only scratched the surface here. In addition, vendors often dont make things easy for you because they use virtualization and its related terms in a very casual manner. Its not enough to simply say that a cluster of computers is a grid solution. Unless the applications running on that cluster can dynamically use the clusters resources as needs change, its not a grid, its simply a cluster. That said, maybe all you need is a cluster. Understanding your needs as well as the complications of virtualization is a must if youre really to make the most of this megatrend. After all, you want to really see this elephant, not just one side of it. Ziff Davis Internet Senior Editor Steven J. Vaughan-Nichols has been working and writing about technology and business since the late 80s and thinks he may just have learned something about them along the way. Check out eWEEK.coms for the latest utility computing news, reviews and analysis.
IDC considers some application server software and parallel database software to fit into this category.