Waking up to the full extent of virtualization options

While doing my morning expedition through the wilds of news sites, blogs and, of course, comic strip sites, I came across something by Laura McCabe, a partner at Hurwitz and Associates, titled "What is Virtualization, and Why Should You Care?" While Laura's comments are useful, she didn't try to present a model of virtualization technology that is comprehensive.

Several important categories, such as storage virtualization, security for virtualized environments and management for virtualized environments were not mentioned at all. Processing virtualization, which is far more than merely virtual machine technology, was only lightly touched upon.  I suspect this is more related to space limitations than a limitation in Laura's understanding of the environment. Let's look a bit deeper, shall we?

A more comprehensive view of Virtualization

Virtualization has been around for quite some time, first appearing in the world of the mainframe in the late 1960s. It appeared once again in the world of midrange systems in the early 1980s and again in the world of industry standard systems hosting Windows, UNIX and Linux in the 1990s. Virtualization is usually defined as using the excess computing power, storage, memory or some other system resource to place a function into an artificial, illusionary environment that offers enhanced characteristics.

Kusnetzky Group Model

There are many layers of technology that virtualize some portion of a computing environment depending upon whether the organization is seeking performance, reliability/availability, scalability, consolidation, agility, a unified management domain or some other goal. Let’s look at each of them in turn.

• Access Virtualization — hardware and software technology that allows nearly any device to access any application without either having to know too much about the other. The application sees a device it’s used to working with. The device sees an application it knows how to display. In some cases, special purpose hardware is used on each side of the network connection to increase performance, allow many users to share a single client system or allow a single individual to see multiple displays. This is part of the notion of "desktop" or "user" virtualization.
• Application Virtualization — software technology allowing applications to run on many different operating systems and hardware platforms. This usually means that the application has been written to use an application framework. It also means that applications running on the same system that do not use this framework do not get the benefits of application virtualization. More advanced forms of this technology offer the ability to restart an application in case of a failure, start another instance of an application if the application is not meeting service level objectives, or provide workload balancing among multiple instances of an application to archive high levels of scalability. Some really sophisticated approaches to application virtualization can do this magical feat without requiring that the application be re-architected or rewritten using some special application framework. This is another part of what is sometimes called "desktop" or "user" virtualization."
• Processing Virtualization — hardware and software technology that hides physical hardware configuration from system services, operating systems or applications. This type of Virtualization technology can make one system appear to be many or many systems appear to be a single computing resource to achieve goals ranging from raw performance, high levels of scalability, reliability/availability, agility or consolidation of multiple environments onto a single system. One type of processing virtualization, virtual machine technology (sometimes refered to as a "hypervisor"), is also part of the notion of "desktop" or "user" virtualization. Another type, clustering and availability software, can be used to increase reliability and availability.
• Storage Virtualization — hardware and software technology that hides where storage systems are and what type of device is actually storing applications and data. This technology also makes it possible for many systems to share the same storage devices without knowing that others are also accessing them. This technology also makes it possible to take a snapshot of a live system so that it can be backed up without hindering online or transactional applications.
• Network Virtualization — hardware and software technology that presents a view of the network that differs from the physical view. So, a personal computer may be allowed to only “see” systems it is allowed to access. Another common use is making multiple network links appear to be a single link.
• Security for virtualized environments - technology that protects all of the layers of virtualization technology. This layer is designed to assure that the organization's IT resources are used in the proper way only by authorized individuals, from authorized locaitons at authorized times.
• Management of virtualized environments — software technology that makes it possible for multiple systems to be provisioned and managed as if they were a single computing resource.

Snapshot analysis

I'm sure that Ms. McCabe was only touching on virtualization topics that her clients and the audience of that specific website most need to understand.  The topic of virtualization is much broader than what was presented by that article.

How broad a view does your organization have of virtualization technology?