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TRADEMARKS: Wiley, the Wiley logo, and the Sybex logo are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates, in the United States and other countries, and may not be used without written permission. CompTIA Storage+ is a trademark of CompTIA Properties, LLC. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book.

10 9 8 7 6 5 4 3 2 1

Dear Reader,

Thank you for choosing Data Storage Networking: Real World Skills for the CompTIA Storage+ Certification and Beyond. This book is part of a family of premium-quality Sybex books, all of which are written by outstanding authors who combine practical experience with a gift for teaching.

Sybex was founded in 1976. More than 30 years later, we’re still committed to producing consistently exceptional books. With each of our titles, we’re working hard to set a new standard for the industry. From the paper we print on to the authors we work with, our goal is to bring you the best books available.

I hope you see all that reflected in these pages. I’d be very interested to hear your comments and get your feedback on how we’re doing. Feel free to let me know what you think about this or any other Sybex book by sending me an email at contactus@wiley.com. If you think you’ve found a technical error in this book, please visit http://sybex.custhelp.com. Customer feedback is critical to our efforts at Sybex.

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Chris Webb

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Sybex, an Imprint of Wiley

I dedicate this book to the most important people in my life—my wife and children. Thank you so much for being part of my life! And thank you to God, for blessing me with, well, everything!

Acknowledgments

So many people to thank and acknowledge, it’s hard to know where to begin!

First and foremost, thank you to my wife and children for being so amazingly supportive and patient with me during this mammoth writing project. Right before I signed the contract to write the book, I pointed out to my wife, Jen, that just about every book I’ve ever read has started with the words “Thank you to my wife and family who have barely seen me for the last 12 months of writing this book.” Being the amazing person that she is, she grimaced and told me to go ahead and do it. Thank you, Jen; I honestly couldn’t have done it without your support. Thanks also to my wonderful three daughters, Lily, Abi, and Mia, who have had only half a father for the past 10 months. Looking forward to some time with you over Christmas!

I’d also like to thank my parents for putting up with me as a lazy, delinquent youth. Thank you to my late father for buying me my first PC—a 386SX-33 with half a megabyte of RAM and a 40 MB hard disk, which I was told I’d never be able to fill in my entire life! That computer is what got me hooked on IT. I know you’d be proud of me, Dad. Thank you to my mother, who, as a single parent, went out to work to support her family. Hopefully, I’m paying it all back to you now!

Aside from family, I’ve had some top-notch help with this book. Thank you to Howard Marks and Ron Singler, the book’s technical editors. Howard, you’re a legend, and I look up to you as a true “gray beard.” Thanks for keeping me straight throughout the project. Ron, I really appreciate your assistance on this project as well, and thanks again for getting me started blogging all those years ago!

Thank you also to Kelly Talbot, my development editor. I really appreciate the work you’ve put into this project. Your influence now has me spelling words the American way instead of the British way—scary!

A final thanks to Sybex, and Jeff Kellum, for allowing me to write my first Sybex book. I’ve had a love of IT books since I learned Windows NT 4 back in the late 1990s. In fact, my wife, Jen, occasionally reminds me that I took Mark Minasi’s 1,500-page Mastering Windows 2000 Server on our honeymoon with us and proceeded to take it to the pool, the beach, and anywhere else we went! It’s nice to be able to give something back and hopefully influence somebody’s career in a similar way to the way my career was influenced by Mark’s book.

About the Author

Nigel Poulton is a well-known and popular figure in the storage industry. He is the author of a long-running storage blog and hosts a popular technical podcast. Nigel is probably best known for his ambition to tackle deep technical concepts and share them via his website and podcast. Nigel has over 15 years of experience working with IT in a wide variety of industries, including financial services, retail, and government. Nigel has hands-on experience with most things in storage, all the way from pouring cups of tea, resetting passwords, and changing backup tapes, to designing petabyte-scale solutions and having responsibility for live production environments. Nigel lives with his wife and three daughters in England and is available as a consultant.

Nigel can be contacted by email at nigelpoulton@hotmail.com, as well as through contact forms or leaving comments on his blog site (nigelpoulton.com) and his podcast website (www.technicaldeepdive.com).

Table of Exercises

Exercise 3.1 Configuring an MPIO Load-Balancing Policy in Microsoft Windows

Exercise 3.2 Configuring LUN Masking

Exercise 3.3 LUN Presentation in a Cluster Configuration

Exercise 3.4 Configuring Storage Virtualization

Exercise 4.1 Creating a Striped Volume with Linux LVM

Exercise 4.2 Creating a Mirrored Logical Volume with Linux LVM

Exercise 4.3 Creating a RAID 10 RAID Set

Exercise 5.1 Using hashow and slotshow in Brocade Switches

Exercise 5.2 Configuring Zoning

Exercise 6.1 Configuring the Windows Server 2012 Software iSCSI Initiator

Exercise 6.2 Configuring CHAP Authentication on an iSCSI Target (Array)

Exercise 6.3 Configuring CHAP Authentication on VMware ESXi iSCSI Initiator

Exercise 7.1 Exporting and Mounting an NFS Share

Exercise 7.2 Mounting a Remote CIFS Share

Exercise 8.1 Configuring vSphere Replication

Exercise 8.2 Taking a Manual VM Snapshot

Exercise 9.1 Configuring Storage Virtualization

Exercise 10.1 Reclaiming Zero Space on Non-TP-Aware Hosts and Filesystems

Exercise 11.1 Creating a Simple Scheduled Backup

Exercise 11.2 Creating a Backup Retention Policy

Exercise 12.1 Using Perfmon

Exercise 12.2 Using iostat

Exercise 12.3 Configuring an Alert

Exercise 13.1 Racking a New 2U Server

Exercise 15.1 Creating a New Virtual Machine in the Cloud with Windows Azure

Exercise 15.2 Creating a New Virtual Machine in the Cloud with Amazon Web Services

Exercise 15.3 Getting Started with Public Cloud Storage with Amazon S3

Foreword

My experience with storage began in the early 1960s when I was a lab technician at the University of California. I spent late nights operating an IBM 704 computer, processing data from Bevatron bubble chamber experiments and storing it onto IBM 727 tape drives. Registers were manually set through an octal keyboard; programs and data were loaded through a punched card reader; and I was the operating system, loading card decks, mounting and dialing in the tape drives, and servicing the output printers. The 1960s were a period of social and political unrest on the Berkeley campus, and I ended up leaving the university to join the military service, far removed from storage technology.

After five years, I left the military to seek a career in the computer industry. I applied at IBM, hoping to leverage the computer experience from my university days. During my first interview, I was asked what I knew about DASD. I was stunned. In a relatively short span of five years, the world I knew of punched cards, tape storage devices, and printed output was replaced by something called a direct-access storage device. This was my introduction to disk drives. I felt like Rip Van Winkle, who awoke from a 20-year sleep to find the world completely changed. Ever since then, I often wondered if this type of transformation would occur again, and I would wake up one day to find an entirely new world of storage.

In the 40 some years since my introduction to disk storage, I worked for IBM and then for Hitachi Data Systems in the storage industry and witnessed the transformation of storage to where it is today. This transformation did not occur overnight. It happened year after year, and the transformation continues to move forward. While the primary data storage device continues to be a mechanical device that records data as magnetic bits on a rotating disk platter, a tremendous amount of technology has been developed to increase recording densities from 2,000 bits per in2 to 1012 bits per in2 (2 Kb/in2 to 1 Tb/in2). In the last few years, solid-state disks based on flash technology were introduced for high-performance storage requirements. While SSDs were initially 10 times the cost per bit of high-performance hard disks, the price gap is closing as the cost of SSDs is declining faster than hard disk prices.

IT is going through a major transformation today as the confluence of Big Data, cloud computing, social networks, and mobile devices change the way we work with and process information. These changes are driving an accelerating need for more storage. This need for storage goes beyond performance and capacity. It requires technologies to make the storage of data more efficient, more reliable, more available, and simpler to manage, procure, protect, secure, search, replicate, and access as blocks, files, or objects. Storage is much more than the media that holds the data bits.

This book helps the reader understand these requirements for the storage of data today, including the latest storage technologies and how they work together. This is a reference manual for IT professionals who need to make informed decisions in the investment of storage choices.

Hu Yoshida
Vice President and Chief Technical Officer
Hitachi Data Systems

It Pays to Get Certified

In a digital world, digital literacy is an essential survival skill.

Certification proves you have the knowledge and skill to solve business problems in virtually any business environment. Certifications are highly valued credentials that qualify you for jobs, increased compensation, and promotion.

The CompTIA Storage+ Powered by SNIA certification exam covers the knowledge and skills required to configure basic networks to include archive, backup, and restoration technologies.

Additionally, CompTIA Storage+ Certified candidates will be able to understand the fundamentals of business continuity, application workload, system integration, and storage/system administration, while performing basic troubleshooting on connectivity issues and referencing documentation.

Steps to Getting Certified and Staying Certified

Review Exam Objectives | Review the certification objectives to make sure you know what is covered in the exam. http://certification.comptia.org/Training/testingcenters/examobjectives.aspx
Practice for the Exam | After you have studied for the certification, take a free assessment and sample test to get an idea of what type of questions might be on the exam. http://certification.comptia.org/Training/testingcenters/samplequestions.aspx
Purchase an Exam Voucher | Purchase your exam voucher on the CompTIA Marketplace, which is located at: http://www.comptiastore.com/
Take the Test | Select a certification exam provider and schedule a time to take your exam. You can find exam providers at the following link:http://certification.comptia.org/Training/testingcenters.aspx
Stay Certified! Continuing Education | The CompTIA Storage+ certification is valid for three years from the date of certification. There are a number of ways the certification can be renewed. For more information go to: http://certification.comptia.org/getCertified/stayCertified.aspx

How to Obtain More Information

Visit CompTIA online www.comptia.org to learn more about getting CompTIA certified.

Contact CompTIA Call 866-835-8020 ext. 5 or email questions@comptia.org.

Join the IT Pro Community http://itpro.comptia.org to join the IT community to get relevant career information.

Connect with us: We’re on LinkedIn, Facebook, Twitter, Flickr, and YouTube.

Introduction

As one of the three pillars of IT infrastructure (computing, networking, and storage), storage is fundamental to just about every IT infrastructure ever built. This makes managing storage an essential skill for everyone involved in IT infrastructure, from systems administrators to infrastructure architects.

This book was written so that you can gain the required storage knowledge from which to build a successful IT career. Understanding how disk drives, flash memory, and storage arrays work is vital to understanding how to design, implement, administer, and troubleshoot storage environments. The book also includes many real-world examples to help clarify concepts and show how they should be applied. Finally, the book covers all the objectives listed in the CompTIA Storage+ exam (SGO-001). So after reading this book, you will have all the knowledge required to both pass the exam and implement storage in the real world.

We dedicate entire chapters to topics such as cloud and converged infrastructure, which are reshaping the IT world. Software-defined storage is also addressed in various chapters.

This book is written with the assumption that you have very little knowledge of storage and want to get up to speed as quickly as possible. Great effort was made so that fundamentals would not be tedious for any reader who feels they already have a good grasp of the basics but want to deepen their knowledge. Covering the basics in a succinct manner also allows such readers to quickly refresh their knowledge and potentially clarify any areas where they were previously uncertain.

Who Should Buy This Book

Anyone with a career or aspiring to have a career in IT infrastructure should buy this book. That career could specialize in data storage, specialize in operating systems, or include responsibilities that cover all three of the major IT infrastructure components (computing, networking, storage). The reason this book and its topics are important to everyone involved with IT infrastructure is that storage is vital, and you cannot be a true IT infrastructure specialist without a solid understanding of storage. Gone are the days when storage design and management could be overlooked or glossed over.

For the reader who is specializing in storage, this book will cover all the knowledge you require in order to slingshot you a long way down the path to becoming a storage expert. You will want to read all chapters of the book and ensure you are proficient in the material covered in each chapter. Fortunately, each chapter is written so that it can be read on its own (without having to read all preceding chapters).

For the reader who wishes to have a job covering all aspects of IT infrastructure (the IT infrastructure generalist), you may want to use this book as a reference manual and dip in and out of the chapters when necessary. For example, if you need to know how to deploy an iSCSI SAN, read the chapter on iSCSI SAN. Or if you need to deploy a new backup solution, read the chapter on backup and recovery. As mentioned previously, each chapter is written so that you can read it independently.

Finally, anybody who wishes to achieve the CompTIA Storage+ certification will find that this book covers all the exam’s required topics, plus more.

How This Book Is Organized

This book consists of 15 chapters, plus supplementary information and materials: an extensive glossary, an online bonus exam, and 100 online flash cards to help you remember the information covered in the book and prepare you for the CompTIA Storage+ exam. The chapters are organized as follows:

Chapter 1, “Storage Primer,” stresses the important role of storage in today’s world, where high-performance, always-on technology infrastructure is vital to the operation and success of just about every organization.

Chapter 2, “Storage Devices,” provides in-depth coverage of the inner workings of the two major storage mediums in use today: the mechanical disk drive and solid-state media.

Chapter 3, “Storage Arrays,” shifts the focus from individual drives to arrays with massive numbers of pooled drives, and shows how they can improve performance, reliability, and efficiency.

Chapter 4, “RAID: Keeping Your Data Safe,” talks about how RAID technology has kept the world’s data safe for more than a quarter of a century, discusses the various options that have been around for most of those 35+ years, and discusses options for the future.

Chapter 5, “Fibre Channel SAN,” discusses the pros and cons of the Fibre Channel SAN, including deep knowledge of the FC protocol as well as how to deploy it in your organization.

Chapter 6, “iSCSI SAN,” discusses the pros and cons of iSCSI SAN technologies and the various options available when deploying iSCSI, including the all-important network aspect.

Chapter 7, “Files, NAS, and Objects,” covers the two major file-sharing protocols, SMB and NFS, and how they are deployed and secured, as well as introducing the concepts of object storage, compliance archives, and content-addressable storage.

Chapter 8, “Replication Technologies,” covers both synchronous and asynchronous replication technologies implemented at various layers of the infrastructure stack (array, host, hypervisor, application) and the pros and cons of each.

Chapter 9, “Storage Virtualization,” discusses how virtualization is implemented at various layers of the storage stack, with emphasis on controller-based virtualization, and a discussion of software-defined storage (SDS).

Chapter 10, “Capacity Optimization Technologies,” talks about the impact of compression, deduplication, thin provisioning, and tiering technologies, including how they affect performance and work with solid-state technologies.

Chapter 11, “Backup and Recovery,” covers the vital twin topics of backup and recovery and discusses how cloud service can be exploited.

Chapter 12, “Storage Management,” focuses on capacity management, performance management, and general management protocols as they relate to storage.

Chapter 13, “The Wider Data Center Neighborhood,” outlines the data center technologies that most closely relate to storage. Topics such as airflow, cabling, rack stability, and more are discussed.

Chapter 14, “Converged Networking,” covers the emerging area of Fibre Channel over Ethernet and the benefits of a single network for traditional LAN and SAN traffic.

Chapter 15, “Cloud Storage,” deals with the increasingly important topic of cloud services. Public cloud, private cloud, and hybrid cloud are all covered.

The glossary provides concise definitions of all the important terms relating to storage and is a great place for a quick refresher if you can’t remember what a term or acronym refers to. This may also be a great resource to read the morning of your exam, should you choose to take the CompTIA Storage+ exam.

Bonus Contents

This book has a web page that provides several additional elements. Items available among these companion files include the following:

Bonus Exam This book comes with a 100-question bonus exam to help you test your knowledge and review important information.

Electronic Flash Cards The digital companion files include 100 questions in flash-card format (a question followed by a single correct answer). You can use these to review your knowledge.

Glossary The key terms from this book, and their definitions, are available as a fully searchable PDF.

You can download all these resources from www.sybex.com/go/datastoragenetworking.

Conventions Used in This Book

This book uses certain typographic styles and other elements to help you quickly identify important information and to avoid confusion. In particular, look for the following style:

Italicized text indicates key terms that are described at length for the first time in a chapter. (Italics are also used for emphasis.)

In addition to this text convention, a few conventions highlight segments of text:

A note indicates information that’s useful or interesting but that’s somewhat peripheral to the main text.

A tip provides information that can save you time or frustration and that may not be entirely obvious. A tip might describe how to get around a limitation or how to perform an unusual task.

Warnings describe potential pitfalls or dangers. If you fail to heed a warning, you may end up spending a lot of time recovering from a problem.

Sidebars

A sidebar is like a note but longer. The information in a sidebar is useful, but it doesn’t fit into the main flow of the text.

Real-World Scenario

A real-world scenario is a type of sidebar that describes a task or example that’s particularly grounded in the real world. This may be a situation I or somebody I know has encountered, or it may be advice on how to work around problems that are common in real, working environments.

Exercises

An exercise is a procedure you should try out on your own to help you learn about the material in the chapter. Don’t limit yourself to the procedures described in the exercises, though! Try other procedures to really learn about data storage networking.

Chapter 1

Storage Primer

Topics covered in this chapter:

The importance of IT

The role of storage

Types of storage

Where storage fits into the wider IT infrastructure

The influence of flash memory

Cloud storage

CompTIA Storage+ Powered by SNIA exam

This introductory chapter outlines the increasingly important role of technology in the world and how this creates a demand for robust, high-performance, technology-based systems that need good, knowledgeable people to design and administer them. It explains the important place that storage occupies in the world of information technology infrastructure and how it interacts with other infrastructure components such as computing and networking. You will learn about the major forms of storage, including the mechanical disk drive and the new wave of solid-state storage technologies such as flash memory. You will also learn about the influence of the cloud.

The Importance of Information Technology

Information technology (IT) has never been more important than it is now. It is more important than it was yesterday and shows all the signs of being even more important tomorrow. From social media and your personal life, all the way up to major governments and corporations, information and technology are at the center of everything.

In our personal lives, we’re increasingly reliant on our technology devices—smartphones, smart watches, tablets, laptops, and more. Think about how inconvenienced you were the last time your home Internet connection was down. Suddenly you were cut off from the world, isolated, severely limited in what you could do! Even when we’re on the move, we often rely on services such as Google Maps when navigating around big cities or driving our cars. If we’re running late from a meeting and need to know the time of the next train home, where do we turn? Our technology devices, of course. It’s a fact that we’re increasingly reliant on technology in our personal lives.

The same goes for businesses. Businesses are increasingly dependent on information and technology. Try cutting most businesses off from the Internet and see what happens to them! It’s not just the Internet. Cut a business off—in any shape or form—from its information and data, and see how long it takes until that business goes bust!

It was not that long ago that high technology was a nice-to-have feature for most businesses. High-speed Internet connections were a luxury, and instant access to information was something that was nice to have. In today’s world, businesses simply can’t exist without instant access to information and the Internet. In today’s world, technology is the business. No technology, no business!

As a result of this paramount importance and central nature of technology to businesses, it’s vital that businesses have reliable, high-performance technology systems. A low-latency trading company needs super-fast IT systems that enable them to execute as quickly as possible on trades; if they trade too slowly, they stand to lose money. Service companies need reliable, high-performance IT systems that enable them to provide their services to customers; if those services are unavailable or slow, customers will go elsewhere. Online sales companies need high-performance, reliable IT systems to process customer orders; if the online purchasing system is down or too slow, customers won’t be able to buy goods. Hospitals need high-speed, reliable access to patient information in order to make accurate clinical decisions; terrible things can happen to patients if doctors can’t access up-to-date, accurate patient data in a timely manner. Transportation companies need high-speed, dependable access to IT systems in order to provide safe and reliable services such as air-traffic control and train-track signaling. Media companies need high-speed, reliable IT systems to create and deliver high-quality content to subscribers. The list could go on and on.

IT is important, and that fact is not about to change any time soon. In order for companies to have reliable, high-speed IT systems, they need good people to design and manage them, and that’s where you come into the picture!

The Role of Storage in IT

Within the world of IT, storage is one of the three major IT infrastructure systems:

Computing

Networking

Storage

At a high level, we often think of these as three layers: the computing layer, the network layer, and the storage layer. In the computing layer, applications such as web servers, databases, and apps live and run. The network layer provides the connectivity between computing nodes. For example, a common design approach has a computer running a web server service, which talks to a database service running on another computer, all via the network layer. Finally, the storage layer is where all the data resides. A simple analogy is as follows: computing nodes are like vehicles such as cars and trucks; the network layer is like the road infrastructure; and the storage layer is like the offices and warehouses that hold all the goods and stock. This analogy might be a bit crude, but it conveys the basic idea.

Persistent and Nonpersistent Storage

There are several types of storage, but at a high level there are two main types:

Persistent (sometimes called nonvolatile)

Nonpersistent (sometimes called volatile)

As the names suggest, persistent storage is the standard choice for long-term storage of data. We call it persistent, or nonvolatile, because it doesn’t lose its contents when the power is turned off. The spinning disk drive is still probably the most popular form of persistent storage, although flash memory is becoming increasingly popular. Just about every modern personal technology device—smartphone, smart watch, tablet, laptop, and so on—has internal flash memory. Because it’s nonvolatile, when the battery runs out on that device (which happens all too often), your data is safe!

Probably the most common example of nonpersistent, or volatile, storage is random access memory (RAM). Just about all forms and variations of RAM lose their content when the power is removed. So why bother with RAM? Well, it’s fast—quite often a lot faster than many forms of persistent storage. At certain types of operation, RAM can be a million times faster than disk and a thousand times faster than flash.

Generally speaking, when we refer to storage, we are referring to persistent, nonvolatile storage, which is what the majority of this book focuses on. Occasionally you may hear somebody refer to RAM as storage, but it’s rare. Most of the time storage refers to persistent storage, whereas memory refers to nonpersistent technology such as RAM. An exception to this is flash memory, which is a form of persistent memory meaning that we consider it storage (it doesn’t lose its contents when the power goes out) but behaves a lot like memory and is what we call solid state.

Although large chunks of this book are devoted to solid-state storage (SSS), we almost always use the term solid state to indicate that a device is semiconductor-based and has no moving parts. On the other hand, the disk drive is not a solid-state device because it has many complex moving parts and is therefore considered mechanical.

Performance and Availability

Both mechanical and solid-state storage devices have two important characteristics:

Performance

Availability

On the performance front, like everything else in IT, it’s important that storage is fast. But performance can be a somewhat complicated subject in the storage world. For example, the disk drive is that last remaining mechanical component in the computer, and as such, will always struggle to keep pace with its silicon-based neighbors (CPU, memory, and so on). Because of all the mechanical components involved in every spinning disk drive, the disk drive just doesn’t perform well at random workloads. However, it performs excellently at sequential workloads. Flash memory, on the other hand, is like greased lightning when it comes to random-read workloads, and the latest drives based on flash memory are getting faster and faster at sequential workloads, too (some rated at over 400 MBps vs. the latest 15K spinning drives rated at closer to 250 MBps). So storage performance isn’t a simple matter and requires a good level of knowledge of the underlying components. Of course, this book addresses all of this, so if these topics seem complex and daunting right now, they should be as clear as crystal after you’ve read the relevant sections of the book.

On the topic of availability, because of the central and crucial nature of storage in the IT world, it’s of paramount importance that storage solutions are designed to deal with component failures such as failed drives. It’s a fact of life that things break, and as amazing a feat of modern engineering as the spinning disk drive is, spinning drives still break. And when they break, they tend to break in style, usually taking all their data with them. So it’s vital that you understand the concepts that will allow you build highly available, resilient storage solutions. Again, this topic is covered throughout the book.

50-Something Years Young

The disk drive has been around for a long time. There’s a good chance that it’s older than you. Although it’s advanced a lot over the years, it also hasn’t changed too much.

Does it sound like the previous sentence contradicts itself? Let me explain. In 1956, IBM manufactured and shipped the IBM RAMAC 350 disk storage unit. This was essentially the first-ever disk drive and the father of all mechanical disk drives. By today’s standards, it was a bulky beast. Weighing in at over a ton, it stood 5 feet 6 inches tall and sported no less than 24 50-inch platters (disks). Despite its size and weight, it stored less than 4 MB of data (quite a lot at the time). In terms of capacity and physical dimensions, things have advanced by leaps and bounds since then. But architecturally speaking, the physical design of platters, heads, actuators, and spindle motors has stayed pretty much the same.

During the past 50+ years, the mechanical disk drive has entrenched itself as the de facto medium of choice for high-performance, high-capacity persistent storage requirements. Up until around 2009/2010, it was relatively unchallenged in this category. However, significant changes are ripping their way through the storage world, predominantly because of the following two technologies:

Solid-state storage/flash memory

The cloud

Solid-state storage is challenging the supremacy of the spinning disk drive. It is muscling its way into not only personal electronics such as phones and tablets, where it has eradicated the use of the mechanical disk drive, but also the corporate data center. It’s not uncommon for laptops and PCs to ship with solid-state drives (SSDs) rather than disk drives, and many storage arrays in the data center are either all-flash (no disk drives) or a combination of spinning disk and SSD.

The cloud is both interesting and extremely disruptive, albeit more disruptive to corporate and personal IT in general, rather than the disk drive per se. However, whereas a user or organization would once naturally have had data stored on its own spinning disk in its own data centers and equipment, this data is increasingly being stored in the cloud, where technology choices such as disk technologies are somebody else’s responsibility.

Although the venerable disk drive is over half a century old and still going strong, its dominance in the data center and IT devices is being threatened more than ever before. These are exciting times!

The Influence of the Cloud

The cloud is here and cannot be ignored. In fact, the cloud is exciting and is changing the way we design, deploy, and interact with IT. These aren’t just empty promises. The cloud is already here and is delivering on many of its promises.

In a traditional IT infrastructure, a company’s IT assets—their servers, storage, and network equipment—were owned and managed by the company’s IT department. The equipment was typically housed in a computer room or data center and accessed remotely via network links leased by the company. A typical example is a sales company with an office in New York City that is connected to its servers and applications hosted in the company’s own data center somewhere else, such as New Jersey, Boston, or Chicago. In a cloud model, things are different. The company may still have its office in New York, but instead of owning and managing all of its own IT equipment in its own data centers, that equipment is now owned and managed by a cloud provider and sits in the cloud provider’s data centers. That cloud provider could be a public cloud company such as Amazon or Rackspace, a private cloud provider, or a software-as-a-service provider such as Salesforce.com or Google Apps.

In the cloud model, it’s the responsibility of the cloud provider to purchase IT equipment, manage it on a day-to-day basis, upgrade it, deal with failures, manage the data center, and perform all the traditional IT functions. This allows the sales company to get on with its core line of business and not have to worry about managing IT equipment. Instead of the sales company having to buy equipment up front to deal with anticipated growth and demand, it can pay for the use of cloud-based IT resources on a month-by-month basis. For example, imagine that the sales company has moved its IT infrastructure to the cloud and does a steady trade for most of the year but has huge peaks in sales around Black Friday, Cyber Monday, and the Christmas holiday season. If the company’s normal level of trade requires 100 virtual servers and 500 TB of storage, but that requirement peaks for the holiday periods to 250 virtual servers and 750 TB of storage, the cloud is a great choice. This is because for most of the year, the company uses and pays for 100 virtual servers and 500 TB of storage, but then for the holiday periods, it increases the number of virtual servers to 250 and the amount of storage to 750 TB. When the holiday periods are over, the company turns off the additional servers and storage and stops paying for them until the same time next year.

This is just one example of how the cloud is changing the way we consume and pay for IT services. This topic is covered in more detail later in the book.

CompTIA Storage+ Powered by SNIA (SGO-001) Exam

This book covers the topics required for the CompTIA Storage+ Powered by SNIA (SGO-001) exam. However, the book is absolutely far more than an exam prep guide. It covers a lot more material than on the exam and is focused on preparing you for working in the real world. That said, I’ve personally taken, and passed, the exam while writing this book, and I am confident that the book does justice to the materials covered by the exam. But the book also covers more, a lot more.

Chapter Essentials

The Importance of Information Technology IT has never been more important in our personal lives and our businesses. As individuals, we increasingly feel isolated and unconnected without our technology devices. Likewise, businesses are increasingly dependent on technology. The concept of no technology = no business has never been more true.

Persistent Storage Persistent storage, or a persistent storage medium, is one that doesn’t lose the data stored in it when the power is turned off. The disk drive is a prime example. You can turn the power off to a disk drive and power the drive up again a year later, and the data will still be there. The majority of this book focuses on forms of persistent storage and solutions built around persistent storage devices.

Chapter 2

Storage Devices

Topics covered in this chapter:

Storage from 40,000 feet

The mechanical disk drive

Disk drive performance

Disk drive reliability

Solid-state media

Solid-state performance

Solid-state reliability

Tape

Hybrid Drives

This chapter covers everything you will need to know about disk drives and solid-state drives for both your career in IT as well as the CompTIA Storage+ exam.

Because a solid understanding of the disk drive and solid-state technology is so fundamental to a successful career in storage, this chapter covers a lot of the underlying theory in depth. It covers all the major mechanical components of the spinning disk drive as well as diving into the theory and inner workings of flash memory and solid-state technologies. It introduces you to the wildly different performance characteristics of spinning media vs. solid-state media. Each has its place, and it’s not necessarily as simple as saying that flash memory and solid-state technologies will totally replace the spinning disk drive.

After you’ve covered the theory of how these critical data center technologies work, you’ll learn a little bit about their impact on overall performance and availability—which will be crucial to your IT environment. You’ll also learn about capacities and explore cost-related concepts such as dollars per terabyte ($/TB) and dollars per I/O operation ($/I/O operation) and how these cost metrics can be used to make business cases for storage spending.

Storage from 40,000 Feet

The goal of this chapter is to cover everything that you will ever need to know about the storage devices that dominate data centers across the planet. Those devices are as follows:

Disk storage

Solid-state storage

Tape storage

All three are forms of storage, or media.

Disk storage refers to the electromechanical hard disk drive. But as that is a bit of a mouthful, most people refer to it as a disk drive, hard drive, or hard disk drive (HDD). I’ll interchange the terms to keep you on your toes.

Solid-state media refers to a whole bunch of newer technologies that are fighting for a share of the data center oxygen. Many of these are currently flash memory–based, but other forms of solid-state media exist, and many more are on the horizon. This is a particularly exciting area of storage.

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!

Lesen Sie weiter in der vollständigen Ausgabe!