"Virtualization can increase hardware utilization by five to 20 times and allows organizations to reduce the number of power-consuming servers." -- Gartner Data Center Conference, November 2007
The most-significant step most companies can make in their quest for green IT is in IT virtualization, as briefly mentioned in previous chapters. This chapter describes the significant concepts of virtual servers and virtual data storage for energy-efficient data centers. The descriptions include VMware and other server virtualization considerations. In addition, the virtual IT world of the future, via grid computing and cloud computing, is discussed.
Although the use of grid computing and cloud computing in your company's data center for mainstream computing might be in the future, some steps toward that technology for mainstream computing within your company are here now. Server clusters via VMware's VMotion and IBM's PowerVM partition mobility are here now and used in many company data centers. Both of those technologies are described in this chapter.
Based on my experience with data centers for more than ten years, I believe the most important reason to use virtualization is for IT flexibility. The cost- and energy-savings due to consolidating hardware and software are also significant benefits and nicely complement the flexibility benefits.
There are many aspects to IT virtualization. This chapter structure covers the rational, server virtualization, storage virtualization, client virtualization, grid and cloud concepts, cluster architecture for virtual systems, and conclusions.
Over the past 30 or more years, data centers have gone from housing exclusively large mainframe computers to housing hundreds of smaller servers running versions of the Windows operating system or Unix® or Linux® operating systems. Often the smaller servers were originally distributed throughout the company, with small Windows servers available for each department in a company. During the past few years, for reasons of support, security, and more-efficient operations, most of these distributed servers have moved back to the central data center.
Google in the Enterprise SurveyThere's no doubt Google has made headway into businesses: Just 28 percent discourage or ban use of its productivity products, and 69 percent cite Google Apps' good or excellent mobility. But progress could still stall: 59 percent of nonusers distrust the security of Google's cloud. Its data privacy is an open question, and 37 percent worry about integration.