The Many Uses for Server Virtualization

Virtualization is a form of technology that allows one computer to run a simulated version of another computer, called a virtual machine. A virtual machine is different from an emulator because it does not need to emulate the hardware. For example, rather than running a virtual version of a PowerPC operating system within an x86 operating system, you would run two x86 OSes, one on top of the other. The advantage is that, although they both use the same hardware, they can be two completely different operating systems.

Furthermore, because a virtual machine does not have to emulate the hardware, it is usually much faster than an emulator. A virtual machine has direct access to the system's hardware, giving the user of the virtual machine the appearance that they are running the OS in a native environment.

There are many uses for virtualization on servers and in web hosting in particular. With the help of some experts at UK web server hosting company 34SP.com, we have put together a list of some of the common ways in which virtualization is used to make servers better.

Research and Development

Although a virtual machine (the guest) runs within the OS of the host, it cannot affect the host. They are essentially operating as two separate machines. Although the guest is still dependent on the stability of the host, the opposite is not true.

Therefore, a virtual machine is a safe environment to run tests, write code, and experiment. If you completely destroy your OS installation in the process, you can just remove it and start again without affecting the actual server.

With application development, virtualization allows you to build applications for other operating systems. For example, you may have a Linux server, but you can create a virtual machine that runs Windows and develop ASP.NET applications.

Virtual Private Servers

With virtualization you can run multiple instances of operating systems, even if they are identical. You may have a Linux server but need more than one completely independent operating environment. This is ideal for hosting companies that want to offer their users complete control over a virtual server, without having to give them an entire machine for themselves. It allows the hosting company to run multiple servers on one machine.

Virtual private servers (VPS) are cost-effective for the host because they can fit multiple server customers on single machines, and it is also less expensive for customers who want the administrative authority of running a dedicated server, but who do not need the processing and memory power of a full server.

Parallel OS Environments

In some situations, you may need to run specific software only available on a particular operating system but do not want to purchase an entire new server just to run it. For example, if you have a Linux server and numerous websites associated with it, you would not be able to run SharePoint Server without buying a new machine and installing Windows Server 2008 on it. By utilizing virtualization, you can run a guest installation of Windows within your Linux system and install SharePoint on the virtual machine.

In another example, you may just need more than one version of the same operating system for two separate tasks. You may have Linux installed in one instance to act as an application server, but you could then install a virtual machine and run the same version of Linux to run as a web server. If security is ever compromised in the web server, the attackers would still not be able to touch the larger operating system.

Virtualization Software

There is virtualization software available for nearly every operating system (as hosts and guests). Some of the more popular choices include: VMWare, Xen hypervisor, KVM (Kernel-based Virtual Machine), Parallels Virtuozzo, OpenVZ, Windows Hyper-V Server, Virtualbox, and many others.

When choosing a virtualization solution, you need to consider the current operating system you are running and also decide which guest operating systems you intend to use. Not all virtual machines will support every guest OS, and some may run the ones you want to use better than others.

Another consideration is how much money you intend to spend. There are both free/open source and paid solutions. Some are available for one-time fees, while others require annual licensing.

Finally, and most importantly, the purpose of your need for virtualization will have a big impact on the decision to chose a particular solution. OpenVZ, for example, is an excellent choice for virtual private servers (VPS), while Virtualbox is a great choice for testing and development.

Virtualization has many uses and can help make your server more efficient, saving you time and money over the long run. With the right tools in place, it can also be very easy to setup and maintain. For this reason and others, it has become a popular choice for businesses and web hosting companies, and it is one you should definitely consider.

Guest post by: Tavis J. Hampton is a librarian and writer with a decade of experience in information technology, web hosting, and Linux system administration. He currently works for LanternTorch.Net, which offers writing, editing, tech training, and information architecture services.

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