Virtualization of your operating system is not a new concept. While as the old saying goes, “there are always two sides to the medal”, the advantages of virtual hosting (the shiny side) are beginning to far outweigh the disadvantages (the dark side).
Let’s begin by taking on the dark side first. Given that all resources are finite, you may find a guest operating system operating rather sluggishly. The most common reason for this is when you are virtualizing completely different operating systems. For example, running OS X (Snow Leopard, or Lion) to host virtualization software so that you can experiment with a relatively alien operating system such as Windows 7.
Because the two have little in common the lower-level functionality (actions that happen in the kernel of the operating system) cannot be passed on from the host operating system to the guest operating system utilizing the virtualization software as a high-speed two-way pipe. In other words, it becomes a whole system virtualization. Since required tasks cannot be shared they must be re-created.
Depending on the virtualization software you are using, it may not support the virtual operating system passing through system calls even when they are similar or the same Operating System (OS). Saying which will do what is beyond a simple article because there are so many variables and due to the hot competition, the vendors are adding features on an extremely rapid basis.
Companies that are running OS X for servers might want to consider Parallels Server for Mac 4.0. The offering is hypervisor-based, making it performance effective to mix OS X for some operations and Windows server for product specific applications such as Exchange.
A quick side note for firms that are using Windows-based servers. The Mac heads know something you don’t, and that is how to save money. Microsoft charges on a per user basis a licensing fee for its servers. OS X is a one-time fee for its server edition and is limited only by the hardware is installed on. There is no per user license fees. The end result frees up a great deal of the budget for IT.
Setting aside large companies, let’s say you work for a smaller firm called: Me-Myself &I Co. – technically this is known as desktop or client virtualization.
Just as with the enterprise group, the amount of resources used will depend on whether you are using hypervisor technology. Again, there are too many variables for simple binary choice of do this or that.
With all that said, there are still a number of advantages in most applications. Let’s look at some examples.
Suppose you are running OS X and you want or need to run Windows. Should one of the bad guys be running an attack on your computer he very well may be looking to exploit a Windows vulnerability. Having OS X as the base operating system, the attack stopped cold. This leaves only “clean calls” reaching Windows.
Another advantage of current virtualization software is its flexibility of allocating resources. It takes a page from teachers found in cloud computing. That is to say, it is possible to dynamically allocate CPU usage and RAM requirements on-the-fly.
The end result is whatever investment was made in hardware can be more fully utilized. This results in less upfront cost. On an ongoing basis, this also means less power consumption, therefore a lower electric bill. Further, this means less heat is generated, which reduces cooling requirements. And this in itself reduces both the upfront and ongoing costs of dealing with the waste heat.
