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83951c01.qxd:Layout 1 1/24/07 10:14 PM Page 3 CHAPTER 1 Blades and Virtualization Building Blocks for Next- Generation Data Centers Over the past 40 years, tremendous advances in the size, speed, costs, usability, and management of computer technology have been made. From the mainframe era of the 1970s, through the PC and workstation era, the client/server era, and the Internet era of the 1980s and 1990s, and now to the current consolidation era, computing has changed. As a result, the world had been transformed. Many of these changes have occurred through a slow evolution; however, some technology advancements caused major paradigm shifts both within IT and in business operations. The commoditization of the PC, for example, created a paradigm shift in computing that is still evident today. The popularization of the Internet provides another example. The most recent evolutionary step in computing has been the introduction of blades and virtualization. Today blades and virtualization, as complementary technologies, promise to be the catalysts for the next revolution in computing. Blades and virtualization are key enablers of true utility computing, an environment in which components are added (provisioned) when they are needed, where they are needed, and only for as long as they are needed to give control back to businesses. What Are Blades? Blades are a new form factor for computer technology, which packages ultrahigh density components including servers, storage, and communications 3
83951c01.qxd:Layout 1 1/24/07 10:14 PM Page 4 4 Part I Technology Evolution interfaces in a prewired chassis with shared components such as power, cooling, and networking. In contrast to the traditional horizontal positioning within a rack (rack-mounted servers), blades are typically (though not always) installed vertically in a blade chassis, like books in a bookshelf. In addition to the high density, prewiring, and shared components, an important differentiator between blades and conventional servers is the incorporation of remote out-of-band manageability as an integral part of each blade device. This is fundamentally different from conventional servers (rackmount or stand-alone) where systems management has been designed as an add-on capability. The blade approach shown in Figure 1.1 offers considerable space savings over rack-mounted (1U) servers. For example, 60 blade servers can fit in the same physical space as 42 rack-mounted servers. Figure 1.1: Example of blades in a chassis Source: IBM Server Blades and PC Blades Most of the buzz about blades has focused on blade servers as an upgraded alternative to rack-mounted server farms. When one is implementing blade technology, blade servers are generally the starting point. However, there are other types of blades.
83951c01.qxd:Layout 1 1/24/07 10:14 PM Page 5 Chapter 1 Blades and Virtualization 5 In addition to building servers on blades, a number of vendors have delivered PC blade products. In a PC blade implementation, end users operate with only a monitor, a keyboard, and a mouse (and/or in some cases a specialized client device), and the PC runs on a central blade. PC blades offer the ability to recentralize certain aspects of distributed computing. They offer improvements in physical security and manageability by locating the actual compute and storage components in a central location, allowing easy access for IT as well as centralized maintenance and management while providing a desktop environment for the end user, similar to having a local PC. Storage and Network Blades Blade technology also extends to other components of computing, including storage and networking. Since blade servers require access to information, the choice is whether to incorporate storage on the blade server itself, utilize storage or networking protocols to communicate with standard storage devices outside of the blade environment, or utilize storage blades. All of these options have pros and cons, of course, to be discussed in depth later in the book. The same issues and options are true for general networking requirements. As blades have become more popular, networking vendors have seen the opportunity, and network modules (sometimes called switch blades) for both IP and Fibre Channel networks are available for blade server systems from multiple vendors. Why Blades? Since their introduction in 2001, blade systems have gained significant traction in the enterprise space. Reasons for implementing blade systems versus rackmounted servers will be discussed in detail later, but here is a summary: Space savings and efficiency packing more computing power into a smaller area Consolidation of servers to improve and centralize management as well as to improve utilization of computer assets Simplification and reduction of complexity (modularity, ease of integration, prewired configurations, shared components), ease of deployment, and improved manageability and serviceability Return on investment (ROI) and improved total cost of ownership (TCO) through increased hardware utilization and reduced operating expenses (OpEx)
83951c01.qxd:Layout 1 1/24/07 10:14 PM Page 6 6 Part I Technology Evolution What Is Virtualization? Virtualization is the ability to create a logical abstraction of physical assets. In the case of server virtualization, it allows for multiple virtual servers to run on one physical server, thereby consolidating many physical servers onto one. There are several approaches to server virtualization, which will be discussed in detail later in the book. Why Virtualization? Since server virtualization allows multiple virtual servers to run on one physical server, by its nature it consolidates servers and applications. This increases server utilization and helps address the problem of server sprawl. A Gartner Survey in 2005 showed that 60% of users surveyed had consolidation projects underway, and an additional 28% were looking into it. Cost-reduction pressure, very low server-utilization rates (often under 5%), and the need for improved management have been key drivers. Reduction in the number of servers from virtualization yields direct savings in hardware, power and cooling, and floor space, reducing both capital expenses (CapEx) and ongoing OpEx. In addition, the ease of deployment of virtual machines and advanced management capabilities in the virtualized environment contribute to reduced OpEx. Why Virtualization and Blades? Blade and virtualization technologies together provide critical building blocks for the next generation of enterprise data centers, addressing a two-fold challenge: The first is to deliver on the ever-increasing need for more computing power per square foot under significant IT operations budget constraints. The second challenge is the management of the geographic proliferation of operational centers, forcing the enterprise data center to operate and be managed as a single entity. Blades bring savings in per-server costs due to consolidation of system resources into a smaller footprint (shared modules and simplified cabling, power and floor space). Virtualization brings additional savings through consolidation of multiple servers onto single blades. The modularity of blades within a chassis make them well-suited to implementation as groups of resources within a virtualized pool. These resources can then be provisioned for various tasks as needed. As requirements grow, it is simply a matter of adding or accessing more blades. This provides a much-needed solution to a very common problem large numbers of poorly utilized servers and PCs coupled with an on-demand need for more computing power. Virtualization
83951c01.qxd:Layout 1 1/24/07 10:14 PM Page 7 Chapter 1 Blades and Virtualization 7 software efficiently manages the processing load on fewer computers running at higher utilization levels to handle the same burden, improving the ability to deliver on-demand while greatly reducing costs. One user of virtualization and blades, when asked where virtualization had presented the biggest benefits, responded, If possible, deploy (server virtualization) on blade servers. The configuration becomes so much more manageable and redundant, and that boosts efficiency even more. Why? Because blades not only take up half the space of traditional 1U servers, but they also share vital resources such as switches and interface cards, allowing for moresimplified, centralized management. Conclusion The high density and modularity that blades offer, together with consolidation of physical systems through virtualization, will allow data centers to pack substantially more computing power into their data centers, achieve higher utilization of that computing power, and reduce their CapEx costs. Racks of blades working together can deliver the equivalent power of supercomputers, and are built on modular components that can be added/subtracted/swapped as needed, at a greatly reduced cost. In addition, the modularity and manageability of blades together with virtualization allows for significant streamlining of operational and serviceability procedures, reducing IT OpEx costs. Furthermore, integrated remote management of blade systems and advanced management capabilities of a virtualized infrastructure allow for ease of deployment, redeployment, and serviceability in a centralized or distributed data-center environment. This chapter introduced the concepts and some of the benefits of blades and virtualization as complementary technologies. In Chapter 2, Evolution of Computing Technology Setting the Stage, we will take a step back to frame the blade and virtualization technologies within the history of computers.
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