Determine Your Hardware Needs
All of the major hardware vendors now offer systems specifically tailored for use with virtualization. These often come prepackaged with software, sometimes at attractive prices.
The systems may also come with specialized vendor support, which may be important for companies that lack virtualization experience or have complex needs.
Even if you do not want to purchase such a package, studying the hardware specifications may be useful for those who want to buy servers from other vendors or who want to run virtualization software on hardware they already own.
One way to get an idea of what will be required is to visit Dell's online Virtualization Advisor, which asks what you are running today and what you'd like to accomplish, and then offers a hardware/software configuration to accomplish that goal.
For example, a company that was running ten stand-alone Xeon-processor servers, with a total of 20GB of RAM and 300GB of storage capacity received a recommendation for two quad-core servers, each with a minimum of 21GB of RAM and 300GB of storage. The recommended solution also included a storage array, a management server, and a backup server.
Such consolidation may not be your goal, but the requirement for a new server with at least as much memory as all the servers you plan to combine, plus an extra 1GB or more for overhead, is a good starting point. A quad-core server may be overkill for a first virtualization project, but a dual-core one may not give you room to grow.
Determine How Many Servers You Need
Some small companies run a single physical server, and keep spare parts around to handle emergencies. Other companies buy two or more servers and may use clustering to provide additional redundancy.
Virtual servers can generally be restored to the same or a different physical server from a snapshot. If multiple servers are available, it may also be possible to drag and drop an application from one server to another, while the application is running. This is an important benefit of virtualization that makes data centers easier to manage and tremendously aids in disaster recovery.
A company's first exploration of virtualization may not include redundant servers, but they offer considerable benefits--at the price of significantly increased costs. As always, customers must gauge the risks acceptable to them and spend accordingly.
Know Where to Find Help--Even If You're Sure You Won't Need It
Vendor support can be great, but it has its limitations. All major vendors offer forums for product discussion and problem solving among customers. Virtualization is very new for most people. Customer-provided support may be able to help when vendors cannot, and the price is right.
You can also hire a vendor or consultant to do much of the work for you. This is not necessary if you are already managing physical servers and are willing to experiment a bit before setting up a production environment.
Very small businesses may want to hire a vendor to manage the project because they lack the necessary IT staff. Large companies may want to hire a consultant to do things such as computing return on investment and developing a project schedule.
Use Virtualization on Your Desktops
Virtualization isn't just for server applications. For example, the "XP mode" for Windows 7 is actually a copy of Microsoft's Virtual PC that can be used to run Windows XP alongside the new operating system.
Through desktop virtualization, a single desktop can run all the operating systems in your company, allowing easy testing before rolling out changes or applications to users. Virtualization is also how Macintosh users are able to run their "second favorite" operating system on their Macs and have a mixed desktop of Mac and Windows applications.
Virtualize Entire Desktop Systems for Your Users
Desktop virtualization is not for everyone. It is possible for a server to deliver an entire desktop and its applications to a remote PC, essentially acting as a terminal. In some industries, this approach makes sense, especially for businesses that are highly regulated and where IT needs especially tight control over user desktops.
Delivering virtual desktops is network and server intensive, and application performance at remote desktops may not be acceptable. However, if you have remote employees and want to strictly limit their access to information, it is one option for doing so.
David Coursey is the author of PC World's Tech Inciter blog. He tweets as techinciter and can be reached using the form at www.coursey.com/contact. He thanks Susan Bradley for technical assistance in the preparation of this article.