By Jonathan Hassell, ComputerWorld.com,
Virtualization -- the move to go from real, physical hardware to virtual hardware -- is being seen as one of the "next big things" in IT. There are more virtualization options for IT departments than ever before, including open-source applications from Xen and Virtual Iron; Microsofts Virtual Server taking off like wildfire; and the venerable VMware products.
But if youre new to this party, you might not know how to get started. In this article, Ill break down a recommended workflow and procedure for assessing if virtualization is right for you and, if it is, how to get things moving. Other resources include a tutorial from VMware that explains virtualization in layman's terms and a vendor-neutral entry on Wikipedia.
1. Determine if you have servers ripe for consolidation
Consolidating hardware is, bar none, the No. 1 reason for considering virtualization. Aging hardware, bursting data centers, burgeoning power needs -- all these factors have played a part in the increase of virtualization. Why should you continue acquiring distinct physical machines when you can move real servers to even bigger machines at a ratio nearing 3, 4, 5 or, even in some cases, 10 to 1?
The first step in virtualization is determining if you have the right type of infrastructure to support it. If you have a lot of machines doing similar tasks, these machines are well suited for virtualization. You also should make sure you have an appropriate number of servers to move -- 10 machines or less, and the payoff begins to be questionable. As you move above 10 potential servers, however, the benefits begin to accumulate.
2. Get the administrative headaches out of the way
Any big, involved move like server consolidation or a large deployment is likely to affect some internal processes. Like any major project, its important to get your stakeholders support and receive management buy-in. Youll most likely need to present a business case for moving to virtual services, including money saved, total financial outlay and other means. You may also have to address staffing: As the number of physical servers is reduced, some budgets dictate that manpower must also reduce by a proportional amount. You may be required to anticipate workloads and quantify the effect that fewer physical servers, but the same or more virtual servers, would have on your departments overall task and time needs.
Also, examine your licensing needs. Depending on what software youll be running on your virtualization machines and what their configurations are, you may need to adjust licensing and purchase additional licenses to cover new CPUs or user bases.
3. Select your hardware and software
There are several choices on the market to assist in your virtualization needs, and theyre all available at a variety of price points. Microsofts Virtual Server and VMwares VMware Server are available at no cost to your organization. Bigger applications, like ESX Server and Xens products, are available at a higher cost but provide more features and better performance. It all comes down to whether you need simple server consolidation, or advanced hosting and network configuration capabilities. Each vendor would be more than happy to help you assess your needs, of course, and several have "starter kits" that let you pilot and explore the technology at relatively low cost.
4. Start moving to virtualization
The big day arrives -- after months of planning and preparation, the time comes to actually move physical to virtual. Consider some migration tools to help you. Microsoft is releasing a tool in the near future that will allow you to move a fully installed server running a supported version of Windows to a virtual hard disk format, which is fully supported by its Virtual Server product. VMware has a similar tool in the works. These migration utilities can save you hours, if not days, of performing the actual move.
Other things to consider:
-- Take advantage of clustering capabilities. Using high-performance clusters gives your virtual machines higher availability while also improving their performance.
-- Think about management. How will your staff manage the virtual machine collection you will have? What scripting languages and APIs do your virtual server software support? Are you able to access certain controls via the command line for simple remote access-based administration?
-- Dont forget about storage. Youll need a very fast disk subsystem to get maximum performance for your virtualized servers. Typically, youll find the biggest bang for the buck is in iSCSI-based disk offerings. They are reasonably priced but have great configurability, and such products are fast, too.
5. Monitor, assess, tweak, improve
As with any ongoing process, its important to keep tabs on the virtualization project as you begin transitioning users and services to the new platform. Establish some performance and usage guidelines and thresholds, and evaluate what these metrics will mean for future tweaks and enhancements. Consider tweaking hardware configurations, network setups or increasing bandwidth as needed. Your job isnt over once the final boot into the virtualized operating system is finished.
Jonathan Hassell is an author, consultant and speaker on a variety of IT topics. His published works include RADIUS, Hardening Windows, Using Windows Small Business Server 2003 and Learning Windows Server 2003. His work appears regularly in such periodicals as Windows IT Pro magazine, PC Pro and TechNet Magazine. He also speaks worldwide on topics ranging from networking and security to Windows administration. He is currently an editor for Apress Inc., a publishing company specializing in books for programmers and IT professionals.
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