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Virtualization has been described somewhat informally as “the ability to run a full operating system on a software platform in such a way that the OS thinks it is running on a “real” computer” (Minasi, Gibson, Finn, Henry, & Hynes, 2010). To be a little more specific (and formal), virtualization is “A framework or methodology of dividing the resources of a computer hardware into multiple execution environments, by applying one or more concepts or technologies such as hardware and software partitioning, time sharing, partial or complete machine simulation, emulation, quality of service, and many others” (Williams & Garcia, 2007). In a nutshell, though, the essence of virtualization is “the act of abstracting the physical boundaries of a technology” (Wolf & Halter, 2005). All three aforementioned sources are consistent with the concept of virtualization as the technology or perhaps more accurately the set of technologies that enable computers to no longer require dedicated use of physical hardware, whether it be disk, CPU, network adapter or other physical resource. It decouples hardware and software, so that a system may utilise – without its knowledge as Minasi, Gibson et al. (2010) put it – a subset or even superset of hardware resources independently of other systems. In other words, one set of hardware may host a number of virtual machines and one virtual machine may be hosted on multiple sets of hardware. As a result, compared to physical machines, virtual systems do not just make more efficient use of existing hardware resources but are also more flexible in that they are easier to provision, maintain and decommission as well as move to alternative physical locations.
Some academics have been slow to embrace these technologies, even viewing these developments in virtualization with some suspicion. Others have adopted it and recognised its value for teaching operating systems, networking and programming, notably McEwan (2002)Correia and Watson (2004) and more recently Dobrilovic & Odadžic (2006), van Aardt and Mossom (2009), and Lunsford (2009). The value of virtualization for providing students with the experience of implementing a variety of “real” systems has gained some level of acceptance in many institutions of higher learning, including polytechnics in New Zealand. One of the reasons for making this a standard approach for providing students with practical ways to implement technologies is that it enables a single physical machine to run many virtual machines with these machines being on the same or different network segments. Much of this is now reasonably well documented but few academics have documented exactly how they use widely available virtualization software to explore a topic or technology with students. This paper aims to do just that.