Storage Area Networks
Authors: Ralph H. Thornburgh, Barry Schoenborn
Venue:  (2000)

From the Book:PREFACE: PrefaceInformation Technology requirements change every day, but one requirement that hasn't changed since the inception of data processing is the demand for fast, reliable, and massive data storage. Economic trends in the 1990ssuch as the rapid development of e-commerce, the globalization of business, and the mergers of already-giant corporationshave only escalated the demand.Traditional data storage methods cannot keep pace with the demands placed on them. Enterprises require more information, delivered faster, and with complete reliabilityand traditional methods are failing to deliver. In fact, any time the word "traditional" is used in reference to an IT methodology, there is a strong implication that the methodology is out of date.The Storage Area Network (SAN) is the newest concept and technology for providing fast and reliable mass storage. The SAN meets today's need to store enormous amounts of data and deliver that data at tremendous speed without failure.The SAN exhibits a flexibility for expansion and performance improvement that is typically referred to as "scalability," but that word too often limits our thinking to numbers of devices or their capacities. How big is a disk drive? How many of them can I hook up? Yes, a SAN is scalable in the conventional sense, but it requires an additional descriptor.That descriptor is "modularity." In Future Shock, Alvin Toffler called for modularity as a method of dealing with and surviving rapid change. Individual parts of an entity have a limited lifespan, but can be changed out, so the overall entity has a longer lifespan. The StorageAreaNetwork is highly modular, and that's one of its best features. The capabilities of SAN components are increasing even as this book is being written. To be sure, the SAN is scalable. It can accommodate a large number of devices and store great volumes of data. Because a SAN is part hardware, part software, and part concept, it has durability and flexibility. It defies that traditional First Law of Information Technology: "As soon as you buy the product, it's obsolete." The Storage Area Network is vital to Information Technology in the 21st century and will be with us for a long time.What This Book Is AboutThis book is a comprehensive introduction to Storage Area Networks for IT professionals who must gain familiarity with this new technology.The purpose of this book is to familiarize you with SAN technology and demonstrate its practical application in the IT environment.You may have read an article or two about SANs, or you may have read an entire book. Chances are, however, that you have not yet encountered enough material in one publication to give you a complete SAN picture. We have found that even highly experienced system or network professionals are unfamiliar with SAN functionality and terminology.The book opens with the basics, looking at the core definition of a SAN, a historical perspective on traditional storage (and its limitations), and the rudiments of Fibre Channel, the enabling technology for the SAN.The middle part of the book is intended to be a comprehensive rundown of the SAN: the many ways to configure a SAN, advice on building your own SAN from your current legacy equipment, the workings of SAN backup, and managing the SAN. There's also an extensive chapter describing Hewlett-Packard SAN products.The final portion of the book is an exercise in predicting the future. We begin with a brief interview with Duane Zitzner, President of Computing Systems at Hewlett-Packard, to provide a sense of HP's commitment to the SAN in the future.We then anticipate how the SAN will promote dramatic changes in existing applications and will very likely create brand new applications. If technology moves at its present pace (and we have no reason to doubt that) many of our speculations will be turning into realities even as this book is published.Who Should Read This BookRead this book if the concept, terminology, or setup of a Storage Area Network is new to you. Whether you are an experienced IT professional or a new practitioner, you will want to make these terms and this technology part of your background.If you are planning a new SAN, converting your present storage solution to a SAN, or building out your present SAN, you will find useful concepts and ideas in this text.Whether you work in an all-HP shop, a non-HP shop, a heterogeneous environment, or a mainframe data center, you will still find applicable information here. We describe Hewlett-Packard hardware and software products extensively, because we are very familiar with them, and we also happen to believe they are outstanding in performance, quality and reliability.If you fall into one of the following groups, this book should be of value to you: System administratorsthose who control computer system configurations and resources Network administratorsthose who configure and support networks Technical support/Response center engineersthose who support and troubleshoot mass storage resource problems for customers IT executivesthose responsible for acquiring and deploying storage technology solutions IT studentsthose who want to get up to speed on real world business challengesThere's another person this book is intended for. That's the person who is or wants to become an IT SAN management professional. That's an individual who specializes in managing enterprise storage. The job title isn't in common use yet, but we think it will be used widely in the very near future.By the way, it's also our intent that this book be informative, challenging, and fun for any general reader who wants to keep up with the latest technology.How to Use This BookLike any authors, we would be flattered if you read this book from cover to cover, from beginning to end. If you do, you'll find a planned progression from essential background information to comprehensive how-to techniques and a vision of the future. If you are unfamiliar with SANs, this is the recommended approach.However, there are no doubt many calls on your time, and you may not be able to conveniently read all of this book. If that's the case, use it as a reference.For example, if the development of storage doesn't interest you, or you are already familiar with the fundamentals of Fibre Channel, skip those chapters. To explore topologies or review Hewlett-Packard SAN products, go straight to those chapters.If you are in a very great hurry, read the compact summary below.Chapter 1: The Storage Area Network. We introduce and define the SAN, establish its value, and describe its component technologies.Chapter 2: A Brief History of Storage. This chapter contains a chronology of storage, from the Big Bang (actually, a little later) up to today's non-SAN solutions. There is value in seeing the progression of storage innovations that brought us to the SAN.Chapter 3: A Brief Review of Fibre Channel. Fibre Channel is the enabling technology of the SAN. SANs won't work without it. This chapter explains the significant concepts, presented in as compact a form as possible.Chapter 4: The SAN in Detail. This chapter explores an extensive array of device and connectivity options, and brings out the advantages and disadvantages of each.Chapter 5: Managing the SAN. The best SAN is a well-managed SAN. This chapter describes HP management and monitoring software for devices and SANs.Chapter 6: Backup and Restore. Despite the reliability of a SAN, you still need to plan for backups and restores, offsite storage, and disaster recovery scenarios (when in doubt, make a copy). This chapter covers those topics.Chapter 7: Industry Implementations. The SAN is not a theoretical construct; it exists in many business sectors and can dramatically increase efficiency. You'll also see that some SAN-based data management techniques, such as backup or disaster recovery, cross all major industry sectors.Chapter 8: Hewlett-Packard SAN Products. This chapter catalogs the principal SAN products available from Hewlett-Packard and shows how they can be implemented in your SAN.Chapter 9: An Interview with Duane Zitzner. We ask a senior HP executive to describe HP's positioning and commitment to SAN technology in times to come.Chapter 10: Future Developments. We look to the future, exploring emerging applications that will use SANs. We offer a final word about SANs.Glossary. A glossary can be one of the most useful parts of a book. We have included a wealth of SAN and Fibre Channel terms.About the AuthorsRALPH THORNBURGHRalph Thornburgh has worked for Hewlett-Packard Company for 25 years as an IT trainer, IT Data Center Manager, and Learning Products Engineer (technical writer). He worked in Information Systems for 13 years (as a trainer for three years and a Data Center Manager for 10 years). For the last 11 years he was a Learning Products Engineer. He is currently a Training Engineering Consultant for the Integration Testing and Training Team, Business Process Information Engineering Section, Business PCs North America, at Hewlett-Packard in Roseville, CA.During this time he created 24 classes for Hewlett-Packard data center employees and support personnel worldwide. He has also written numerous user manuals and technical support manuals. He led the team that wrote the multicourse training program for Hewlett-Packard's implementation of Fibre Channel for Mass Storage and two classes for other Hewlett-Packard Fibre Channel peripheral devices. Recently, he led the team that wrote the documentation set for HP's newest mass storage device, the SureStore E Disk Array XP256, containing one familiarization guide and seven user guides for the product's monitoring and management software.Ralph held a secondary teaching certificate for three years. He designed and delivered computer class curriculaincluding courses on operating systems and computer operationsfor The Computer Learning Center in Santa Clara, CA. He also designed, developed, and delivered an American Sign Language (ASL) course for middle-school children. Ralph was in the U.S. Army for eleven years and is a Vietnam veteran. He spent time in the California Army National Guard as a section training sergeant, training soldiers in technical skills, such as aviation electronics, and basic combat skills, such as land navigation (map reading) and basic marksmanship. Ralph is the author of Fibre Channel for Mass Storage, a book about the fundamentals of Fibre Channel and Hewlett-Packard's Fibre Channel products.BARRY SCHOENBORNBarry Schoenborn is an independent technical writer with over 29 years experience creating documentation for computer hardware and software. He owns Willow Valley Software, a technical documentation company located in Nevada City, California. He has provided documentation services to Hewlett-Packard Company for the last seven years. He has documented Fibre Channel host bus adapters for the System Interconnect Solutions Lab in Cupertino, network appliances for the Network Peripheral Solutions Division in Roseville, tape devices for HP's Worldwide Technology Expert Center in Texas, and mass storage for the Enterprise Storage Business Unit in Roseville.Barry has written dozens of user and service manuals for HP devices and software. Recently, he worked on the team that wrote HP's Fibre Channel for Mass Storage training and the documentation set for HP's newest and largest mass storage device, the SureStore E Disk Array XP256.He has owned his own company for 17 years. In addition to HP, clients have included The Money Store, Mitsubishi, and Delta Dental Plan of California. Prior to that, he worked for Xerox Corporation, McDonnell Douglas, Aratex, and Beneficial Standard Life Insurance Company. He has worked as a programmer, computer operator, and EDP auditor.Barry also operates Willow Valley Press, which publishes the works of local authors. He writes a monthly political column for The Union newspaper of Grass Valley/Nevada City, and makes frequent appearances on the Nevada County News Hour on community access television.