Mastering VMware vSphere 5.5

By Scott Lowe, Nick Marshall, Forbes Guthrie and 2 more

The 2013 edition of the bestselling vSphere book on the market

Virtualization remains the hottest trend in the IT world, and VMware vSphere is the industry's most widely deployed virtualization solution. The demand for IT professionals skilled in virtualization and cloud-related technologies is great and expected to keep growing. This comprehensive Sybex guide covers all the features and capabilities of VMware vSphere, showing administrators step by step how to install, configure, operate, manage, and secure it.

This perfect blend of hands-on instruction, conceptual explanation, and practical application is reinforced with real-world examples. Led by Scott Lowe and Nick Marshall, both VMware vExperts, the author team provides expertise that will prepare IT professionals to excel in using this virtualization technology.

• Virtualization is seen as a "best practice" for high availability and disaster recovery solutions, as well as for applications such as Exchange Server and SharePoint
• IDC estimates that there are as many as 7 million jobs available worldwide in virtualization and cloud technology
• Provides hands-on instruction in all the latest features and capabilities of VMware vSphere, with both conceptual explanations and practical applications
• Author team is lead by Scott Lowe and Nick Marshall, well-known VMware experts and popular bloggers

Mastering VMware vSphere provides what every virtualization professional needs to know.

• Language: English
• Publisher: Wiley
• Release date: Oct 16, 2013
• ISBN: 9781118825037

Scott Lowe

Scott Lowe, P.E., has directed and performed all types of analyses related to claims including delay and inefficiency (typically using measured mile for inefficiency); assessed responsibility for contract changes; and calculated various types of delay damages. He has evaluated problems and offered solutions on almost every type of project including transportation, water and wastewater treatment, power, process and manufacturing, medical, educational, commercial, correctional, hotels, condominiums, residential, and athletic facilities. He has worked on projects large and small throughout the US and internationally.

Book preview

Dear Reader,

Thank you for choosing Mastering VMware vSphere 5.5. 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 [e-mail]. 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.

I dedicate this book to my wife, Natalie. Your support and encouragement is unwavering. I couldn't have completed such a task without you. I also dedicate this book to my mother. Mum, you were taken too soon but you still influence me every day.

—Nick Marshall

This book is dedicated to my Heavenly Father, who gives me lots of good and perfect gifts (James 1:17 NIV). The opportunity to write another book is one of those gifts, but more precious than that is the gift of family: my wife and my truest friend, Crystal; my kids (Summer, Johnny, Mike, Liz, Rhys, Sean, and Cameron); and those who have been brought into my family (Matt, Christopher, and Tim).

—Scott Lowe

Acknowledgments

When Scott Lowe expressed his interest to collaborate on a writing project, I would never have believed the journey that was to follow. It's been a rollercoaster, but one I have thoroughly enjoyed. While writing a book has been a huge learning curve for me, one thing is certainly clear: You can't underestimate how important those around you really are.

First of all I want to say thank you to Scott. Handing me such a great responsibility is an honor I will never forget. Your generosity is continuously evident to this day, and your reputation in the industry is second to none. Your work in Chapters 1 and 5 are top notch (as usual), and I hope we can work together again in the future.

Second, I want to say thank you to my contributing authors, Forbes, Matt, and Josh. Your ability to hit the ground running and produce quality work was a real blessing for me as I found my feet. Forbes, your advice and efficiency writing Chapter 4 was much appreciated. Matt, your commitment to Chapter 9 while running many other projects is an inspiration. Josh, thank you for stepping up and sharing your skills in Chapter 14; I couldn't have done it without you.

I'd also like to thank my technical editor, Jason Boche. Jason, thank you not just for finding my mistakes, but also for giving me a more detailed understanding on certain things. This book is better thanks to your attention to detail.

The team at Wiley/Sybex has been so supportive throughout this process, and I'm very grateful of their leadership. Mariann Barsolo, thank you for putting up with my never-ending questions; Stephanie Barton and Dassi Zeidel and the rest of the editing team, thank you for all that you did to ensure the quality of this work and also for understanding all my strange Australian spellings.

There have also been a number of people who helped ensure that the project was a success. Duncan Epping, thank you for your words of wisdom when I was starting out. Grant Orchard, thank you for reading my first drafts. Trevor Roberts Jr., thank you for getting me out of a bind when I needed it most. Fausto Ibarra, thank you for reaching out and getting me in touch with the right people. I'd also like to thank the VMware community as a whole. To all the bloggers, speakers, tweeters, and podcasters: Without you all I would never have started down this road.

Finally, I would like to thank VMware—not only does this company provide me employment, but without VMware this book and more importantly this industry, would not be what it is today.

—Nick Marshall

There are some things that get easier after you've done them multiple times. Acknowledging all the people whose support makes writing a book possible isn't one of those things.

I'll start by thanking Nick Marshall, my partner in crime for this book and the bearer of the torch for future revisions of Mastering VMware vSphere. I'm thrilled to have had the opportunity to work with you, and I'm equally thrilled to know that this book series is as much a labor of love for you as it has been for me. I look forward to seeing future editions.

I'd also like to thank the contributing authors (in no particular order): Forbes Guthrie, Matt Liebowitz, and Josh Atwell. Thank you all for your hard work and your contributions.

As with any technical book, technical accuracy is critical. My thanks go to Jason Boche, who served as the technical editor for this edition. Jason, your oversight helped make sure that we all got the details correct. Thanks for your feedback, corrections, and constructive criticism.

Next, my thanks go to the entire Sybex team: Mariann Barsolo, the acquisitions editor; Stephanie Barton, the developmental editor; Dassi Zeidel, the production editor; Judy Flynn, the copyeditor; Rebecca Rider, the proofreader; Pete Gaughan, the editorial manager; and Neil Edde for his support. I don't know how the book publishing process works with other publishers, but I can say that you guys have made the process as painless as something like this can be. Thanks for everything.

Finally, thanks to my family for all their support. Crystal, I can't express how much your support has meant to me since I started down the book writing path in 2009. Someday I'll figure out how to repay you. Thanks also to my kids, Sean and Cameron, for putting up with deadlines and late nights spent writing at the computer. I really appreciate your support.

—Scott Lowe

About the Authors

Nick Marshall is a consultant with over 13 years IT experience and holds multiple advanced IT certifications, including VMware Certified Advanced Professional 5—Datacenter Administrator (VCAP5-DCA), and VMware Certified Advanced Professional 5—Datacenter Design (VCAP5-DCD). Currently working for VMware, he delivers virtualization and cloud solutions to some of the biggest organizations in the Asia-pacific region.

Previously, Nick has worked in a number of roles ranging from computer assembler to infrastructure architect and has gained experience across the board. Nick is particularly proud of his ability to solve business problems with technical solutions.

Outside of his day job, Nick continues to work on his passion for virtualization by helping run the most popular virtualization podcast, vBrownBag, and writing on his personal blog, at www.nickmarshall.com.au. You can also find him speaking at industry conferences such as VMUG and PEX. To recognize his contributions to the VMware community, Nick has been awarded the vExpert award for both 2012 and 2013.

Nick lives with his wife, Natalie and son, Ethan in Sydney, Australia.

Scott Lowe is an author, consultant, speaker, and blogger focusing on virtualization, networking, storage, and other enterprise technologies. Scott is currently a technical architect at VMware, focused on software-defined networking (SDN) and network virtualization.

Scott's technical expertise extends into several areas. He holds industry certifications from Cisco, EMC, Microsoft, NetApp, VMware, and others. He also holds the premier VMware Certified Design Expert (VCDX) certification; Scott is VCDX #39. For Scott's leadership in, support of, and involvement with the VMware community, he has been awarded the vExpert designation for all five years since the program's inception (2009, 2010, 2011, 2012, and 2013).

As an author, Scott has contributed to numerous online magazines focused around VMware and related virtualization technologies. He is regularly quoted as a virtualization expert in virtualization news stories. He has five other published books: Mastering VMware vSphere 4; VMware vSphere 4 Administration Instant Reference (with Jase McCarty and Matthew Johnson); VMware vSphere Design (with Forbes Guthrie and Maish Saidel-Keesing); and Mastering VMware vSphere 5 and VMware vSphere Design, 2nd Edition (both with Forbes Guthrie), all published by Sybex.

As a speaker, Scott has spoken at several virtualization conferences as well as at VMworld every year since 2009. He regularly speaks at VMware user group meetings, locally in the United States as well as worldwide.

Scott is perhaps best known for his acclaimed virtualization blog at http://blog.scottlowe.org, where he regularly posts technical articles on a wide variety of topics. VMware, Microsoft, and other virtualization industry leaders regularly refer to content on his site, and it is regularly voted among the top five virtualization weblogs worldwide. Scott's weblog is one of the oldest virtualization-centric weblogs that is still active; he's been blogging since early 2005.

Scott lives near Denver, Colorado, with his wife, Crystal; his two youngest sons, Sean and Cameron; and—during the school year—his Chinese exchange student, Tim.

About the Contributors

The following individuals also contributed to this book.

Forbes Guthrie (Chapter 4) is an infrastructure architect who specializes in virtualization. He has worked in a variety of technical roles for over 15 years and achieved several industry certifications, including VMware's VMware Certified Professional—Datacenter Virtualization (VCP2/3/4/5-DV), VMware Certified Advanced Professional 5—Datacenter Administrator (VCAP5-DCA), and VMware Certified Advanced Professional 5—Datacenter Design (VCAP5-DCD). His experience spans many industries, and he has worked in Europe, Asia-Pacific, and North America. He holds a bachelor's degree in mathematics and business analysis and is a former captain in the British Army.

Forbes is the lead author of the first (vSphere 4) and second (vSphere 5) edition of the acclaimed book VMware vSphere Design, co-authored by Scott Lowe. He also contributed to Scott's book Mastering VMware vSphere 5. Forbes has spoken at VMware's own VMworld conference on the subject of design and vSphere 5.

Forbes's blog, www.vReference.com, is well regarded in the virtualization field and is aggregated on VMware's Planet V12n website. He is probably best known for his collection of free reference cards, long revered by those studying for their VMware qualifications. Forbes has been awarded the luminary designation of vExpert by VMware for his contribution to the virtualization community since its inception. His passion and knowledge have also been rewarded with the peer-reviewed top virtualization bloggers listing for the last five years.

Matt Liebowitz (Chapter 9) is an advisory solution architect with EMC Consulting with a focus on virtualizing business-critical applications. He has been a consultant and architect for over 12 years and has been working with VMware's enterprise virtualization products since 2002. Matt is an author of several books on virtualization, is a frequent contributor to the VMware Technology Network (VMTN), and has been an active blogger on virtualization since 2009.

Matt is honored to have been named a VMware vExpert each year since 2010 and also holds numerous industry certifications from both VMware and Microsoft. He maintains a virtualization focused blog at www.thelowercasew.com and is active on Twitter at @mattliebowitz.

When Matt is not out virtualizing the world, he is happily spending time with his wife, Joann, and his two kids, Tyler and Kaitlyn.

Josh Atwell (Chapter 14) is a vArchitect for VCE focusing on VMware and automation solutions on Vblock. Over the last 10+ years he has worked very hard to allow little pieces of code to do his work for him through various automation tools, especially PowerCLI. Josh is highly active in the virtualization community where he has led multiple technology-based user groups such as CIPTUG, VMUG, and UCS Users Group.

Josh holds both the VMware Certified Advanced Professional 5—Datacenter Administrator (VCAP5-DCA), and VMware Certified Advanced Professional 5—Datacenter Design (VCAP5-DCD) certifications and enjoys working with others on preparing for their certification pursuits through the vBrownBag podcast. Never known for lacking an opinion, he blogs at vtesseract.com and talks shop on Twitter as @Josh_Atwell. When not helping folks with things that start with v, he enjoys spending time with his children and his supportive wife, who has made everything mentioned possible.

Foreword

Most people out there have a bucket list, a list of things they hope to see, do, or accomplish at some point in their life. One of the items on my bucket list had always been writing a book. The desire to write a book first emerged in my early teen years and continued well into adulthood. No matter how hard I tried, though, it seemed as if this particular bucket list item wasn't going to get checked off the list. I know this seems like an odd statement to make now, but bear with me as I share the story—a story not everyone knows—about how that all changed.

The story starts in 2008. I'd managed to gain some visibility in the VMware community through my live-blogging of VMworld 2007 and VMworld 2008, and it was in 2008 that I met Chad Sakac. Chad is now a senior vice president at EMC Corporation, but then he was the leader of a small team of folks who later became known as the vSpecialists. At the time, making a connection with Chad was simply making a connection with a fellow virtualization geek. We chatted, traded virtualization stories, talked technology for a while, and that was that. Or so I thought.

Fast-forward to early 2009 when, somewhat out of the blue, I received an email from Chad. He'd been approached to write a book on VMware's upcoming vSphere 4.0 product release, the email stated, but he was unable to do it. Would I be interested in writing the book, he asked, saying he thought I'd be perfect for the task. Would I be interested? What a question to ask! Of course I was interested. So I responded in the affirmative, Chad connected me with his contacts at Wiley/Sybex, contracts were signed, and off I went. Later that year, at VMworld 2009, my first book, Mastering VMware vSphere 4, was released and quickly became one of the hottest titles in virtualization. (Chad contributed the chapter about storage in that book, in case you didn't already know.)

The rest, you could say, is history. My second book, VMware vSphere 4 Administration Instant Reference, was co-written with Jase McCarty and Matthew Johnson and released later in 2009. The third book, VMware vSphere Design, was co-written with Forbes Guthrie and Maish Saidel-Keesing and published in early 2011. Mastering VMware vSphere 5, an update to the book that started it all, was released later in 2011. Forbes and I teamed up again for VMware vSphere Design, 2nd Edition, which was released in early 2013.

Naturally, Wiley/Sybex had me in the crosshairs when it came time to talk about revising the Mastering VMware vSphere series for the vSphere 5.5 release. As much as I've enjoyed writing this series, this time around my mind went back to early 2009, and I thought about the excitement I'd felt when I was unexpectedly presented with the opportunity I'd always wanted. Sure, I could write the revision, but how much better would it be if I could pay it forward, so to speak, and give someone else in the community the same opportunity I'd been given? The opportunity to write Mastering VMware vSphere 4 had been generously dropped in my lap; why not do the same for someone else?

The book you're holding right now represents that decision to pay it forward. With the release of Mastering VMware vSphere 5.5, I'm officially passing the torch to Nick Marshall. Nick was a great selection to carry the torch. He'd already demonstrated a commitment to the community through his work on the vBrownBag podcast series as well as through his efforts with Alastair Cooke on AutoLab. During the writing of this book, I've been impressed with Nick's knowledge, dedication to quality, and attention to detail. I'm very excited about Nick taking over the series, and I hope you are as well. I further hope that the VMware community offers Nick the same level of support, feedback, and encouragement along his journey as an author as I have received during my journey.

I'm confident that you'll find this book to be every bit as useful, informative, and valuable as previous versions in the series have been. Nick, along with myself and a team of rock star contributors including Forbes Guthrie, Matt Liebowitz, and Josh Atwell, have put forth every effort to make sure that we have comprehensively addressed the new features and functionality in vSphere 5.5. This includes major new features like VSAN and expanded support for networking protocols like LACP. There's too much to mention here, but rest assured that the entire team has worked really hard to make this the authoritative title that you—the community—needs.

vSphere 5.5 represents a new release for VMware, and Mastering VMware vSphere 5.5 represents a new release for this series. I hope that you enjoy both.

—Scott Lowe

VCDX, vExpert

Introduction

Back in 2005 I was trying to convince my boss that we should use GSX Server on our shiny new DL385. To him, it was a hard sell. He didn't understand why on earth we should install two operating systems onto a server, It'll just slow it down! he exclaimed. So I went ahead and started experimenting with VMware software on my desktop computer. Luckily at the time I had a workstation capable of running such things.

The times have changed quite a bit since then, and now virtualization—especially server virtualization—is readily embraced in corporate datacenters worldwide. VMware has gone from a relatively small vendor to one of the corporate heavyweights, garnering a commanding share of the server virtualization market with its top-notch virtualization products. Even now, when other companies such as Microsoft and Citrix have jumped into the server virtualization space, it's still VMware that's almost synonymous with virtualization. For all intents and purposes, VMware invented the market.

If you're reading this, though, there's a chance you're just now starting to learn about virtualization. What is virtualization, and why is it important to you?

I define virtualization as the abstraction of one computing resource from another computing resource. Consider storage virtualization; in this case, you are abstracting servers (one computing resource) from the storage to which they are connected (another computing resource). This holds true for other forms of virtualization, too, like application virtualization (abstracting applications from the operating system). When most information technology professionals think of virtualization, they think of hardware (or server) virtualization: abstracting the operating system from the underlying hardware on which it runs and thus enabling multiple operating systems to run simultaneously on the same physical server. That is the technology on which VMware has built its market share.

Almost single-handedly, VMware's enterprise-grade virtualization solution has revolutionized how organizations manage their datacenters. Before VMware introduced its powerful virtualization solution, organizations bought a new server every time a new application needed to be provisioned. Over time, datacenters became filled with servers that were all using only a fraction of their overall capacity. Even though these servers were underutilized, organizations still had to pay to power them and to dissipate the heat they generated.

Now, using VMware's server virtualization products, organizations can run multiple operating systems and applications on their existing hardware, and new hardware is purchased only when capacity needs dictate. No longer must organizations purchase a new physical server whenever a new application needs to be deployed. By stacking workloads together using virtualization, organizations derive greater value from their hardware investments. They also reduce operational costs by reducing the number of physical servers and associated hardware in the datacenter, in turn decreasing power usage and cooling needs in the datacenter. In some cases these operational cost savings can be quite significant.

But consolidation is only one benefit of virtualization; companies also realize greater workload mobility, increased uptime, streamlined disaster-recovery options, and a bevy of other benefits from adopting virtualization. And virtualization, specifically server virtualization, has created the foundation for a new way of approaching the computing model: cloud computing.

Cloud computing is built on the tenets of broad network access, resource pooling, rapid elasticity, on-demand self-service, and measured service. Virtualization, such as that provided by VMware's products, enables the IT industry to embrace this new operational model of more efficiently providing services to their customers, whether those customers are internal (their employees) or external (partners, end users, or consumers). That ability to efficiently provide services is the reason virtualization is important to you.

This book provides all the information you, as an information technology professional, need to design, deploy, configure, manage, and monitor a dynamic virtualized environment built on VMware's enterprise-class server virtualization product, vSphere 5.5.

What Is Covered in This Book

This book is written with a start-to-finish approach to installing, configuring, managing, and monitoring a virtual environment using the VMware vSphere 5.5 product suite. The book begins by introducing the vSphere product suite and all of its great features. After introducing all of the bells and whistles, the book details an installation of the product and then moves into configuration. This includes configuring vSphere's extensive networking and storage functionality. We wrap up the configuration discussion with chapters on high availability, redundancy, and resource utilization. After completing the installation and configuration, we move into virtual machine creation and management and then into monitoring and troubleshooting. You can read this book from cover to cover to gain an understanding of the vSphere product suite in preparation for a new virtual environment, or you can use it as a reference if you are an IT professional who has begun your virtualization and wants to complement your skills with real-world tips, tricks, and best practices as found in each chapter.

This book, geared toward the aspiring as well as the practicing virtualization professional, provides information to help implement, manage, maintain, and troubleshoot an enterprise virtualization scenario.

Here is a glance at what's in each chapter:

Chapter 1: Introducing VMware vSphere 5.5 We begin with a general overview of all the products that make up the vSphere 5.5 product suite. This chapter also covers vSphere licensing and provides some examples of benefits that an organization might see from adopting vSphere as its virtualization solution.

Chapter 2: Planning and Installing VMware ESXi This chapter looks at selecting the physical hardware, choosing your version of VMware ESXi, planning your installation, and actually installing VMware ESXi, both manually and in an unattended fashion.

Chapter 3: Installing and Configuring vCenter Server In this chapter, we dive deep into planning your vCenter Server environment. vCenter Server is a critical management component of vSphere, and so this chapter discusses the proper design, planning, installation, and configuration for vCenter Server.

Chapter 4: vSphere Update Manager and the vCenter Support Tools This chapter describes what is involved in planning, designing, installing and configuring the vSphere Update Manager. You'll use vCenter Update Manager to keep your vSphere environment patched and up-to-date.

Chapter 5: Creating and Configuring Virtual Networks The virtual networking chapter covers the design, management, and optimization of virtual networks, including new features like the vSphere Distributed Switch and other third-party switches. In this chapter we also initiate discussions and provide solutions on how to integrate the virtual networking architecture with the physical network architecture while maintaining network security.

Chapter 6: Creating and Configuring Storage Devices This in-depth chapter provides an extensive overview of the various storage architectures available for vSphere. In this chapter we discuss Fibre Channel, iSCSI, and NAS storage design and optimization techniques as well as storage features like thin provisioning, multipathing, and round-robin load balancing.

Chapter 7: Ensuring High Availability and Business Continuity This exciting chapter covers the hot topics regarding business continuity and disaster recovery. We provide details on building highly available server clusters in virtual machines. In addition, this chapter discusses the use of vSphere High Availability (HA) and vSphere Fault Tolerance (FT) as ways of providing failover for virtual machines running in a vSphere environment. We also discuss backup options using vSphere's Storage APIs.

Chapter 8: Securing VMware vSphere Security is an important part of any implementation, and in this chapter we cover different security management aspects, including managing direct ESXi host access and integrating vSphere with Active Directory. This chapter also covers how to manage user access for environments with multiple levels of system administration and how to employ Windows users and groups in conjunction with the vSphere security model to ease the administrative delegation that comes with enterprise-level deployments.

Chapter 9: Creating and Managing Virtual Machines This chapter introduces the practices and procedures involved in provisioning virtual machines through vCenter Server. In addition, you're introduced to timesaving techniques, virtual machine optimization, and best practices that will ensure simplified management as the number of virtual machines grows larger over time.

Chapter 10: Using Templates and vApps Chapter 10 introduces the idea of templates, a mechanism for more rapidly deploying standardized VM images. We also discuss cloning and the concept of a vApp—a specialized container used by vSphere for the distribution of multi-VM environments. In addition, we discuss the OVF standard used by VMware and other vendors for distributing VMs.

Chapter 11: Managing Resource Allocation In this chapter we provide a comprehensive look at managing resource allocation. From individual virtual machines to resource pools and clusters of ESXi hosts, this chapter explores how resources are consumed in vSphere and addresses the mechanisms you can use—reservations, limits, and shares—to manage and modify that resource allocation.

Chapter 12: Balancing Resource Utilization Resource allocation isn't the same as resource utilization, and this chapter follows up the discussion of resource allocation in Chapter 11 with a look at some of the ways vSphere offers to balance resource utilization. In this chapter, you'll learn about vSphere vMotion, Enhanced vMotion Compatibility, vSphere Distributed Resource Scheduler (DRS), Storage vMotion, and Storage DRS.

Chapter 13: Monitoring VMware vSphere Performance In Chapter 13 we look at some of the native tools in vSphere that give virtual infrastructure administrators the ability to track and troubleshoot performance issues. The chapter focuses on monitoring CPU, memory, disk, and network adapter performance across ESXi hosts, resource pools, and clusters in vCenter Server. In this chapter you'll also learn about vCenter Operations Manager.

Chapter 14: Automating VMware vSphere Many tasks VMware vSphere administrators face are repetitive, and here automation can help. In Chapter 14 we discuss several different ways to bring automation to your vSphere environment, including vCenter Orchestrator and PowerCLI.

Appendix: The Bottom Line This appendix offers solutions to the Master It problems at the end of each chapter.

The Mastering Series

The Mastering series from Sybex provides outstanding instruction for readers with intermediate and advanced skills, in the form of top-notch training and development for those already working in their field and clear, serious education for those aspiring to become pros. Every Mastering book includes the following:

Real-World Scenarios, ranging from case studies to interviews, that show how the tool, technique, or knowledge presented is applied in actual practice

Skill-based instruction, with chapters organized around real tasks rather than abstract concepts or subjects

Self-review test questions, so you can be certain you're equipped to do the job right

The Hardware behind the Book

Starting out, it can seem difficult to build an environment in which you can learn by implementing the exercises and practices detailed in this book. It is possible to build a practice lab with minimal hardware, and we encourage you to follow along with the book. If you're just starting, we recommend building a nested virtual lab on your laptop or desktop computer. Head to www.labguides.com for details on AutoLab, a nested vSphere automation tool. It only needs VMware Workstation or Fusion installed and 8 GB of RAM. Be sure to read Chapter 2 and Chapter 3 before you attempt to construct any type of environment for development purposes.

For the purpose of writing this book, we used the following hardware configuration:

Three Hewlett Packard DL-385 servers

Two Hewlett Packard N36L micro servers

One Qnap 439 Pro II NAS

One generic 24-port gigabit switch

As you can see, it's not impossible to set yourself up with a nice lab to follow along. But for some, this is not the sort of environment to which they have access. For entry-level NFS and iSCSI testing, a number of vendors, including EMC, HP, and NetApp, offer virtual storage appliances or simulators that you can use to gain some familiarity with shared storage concepts and that specific vendor's products. We encourage you to use these sorts of tools where applicable in your learning process.

Who Should Buy This Book

This book is for IT professionals looking to strengthen their knowledge of constructing and managing a virtual infrastructure on vSphere 5.5. While the book can also be helpful for those new to IT, a strong set of assumptions is made about the target reader:

A basic understanding of networking architecture

Experience working in a Microsoft Windows environment

Experience managing DNS and DHCP

A basic understanding of how virtualization differs from traditional physical infrastructures

A basic understanding of hardware and software components in standard x86 and x64 computing

How to Contact the Authors

We welcome feedback from you about this book or about books you'd like to see from us in the future.

You can reach Nick by writing to [e-mail], by following him on Twitter (his username is @nickmarshall9), or by visiting his blog at www.nickmarshall.com.au.

You can reach Scott by writing to [e-mail], by following him on Twitter (his username is @scott_lowe), or by visiting his blog at http://blog.scottlowe.org.

Chapter 1

Introducing VMware vSphere 5.5

Now in its fifth generation, VMware vSphere 5.5 builds on previous generations of VMware's enterprise-grade virtualization products. vSphere 5.5 extends fine-grained resource allocation controls to more types of resources, enabling VMware administrators to have even greater control over how resources are allocated to and used by virtual workloads. With dynamic resource controls, high availability, unprecedented fault-tolerance features, distributed resource management, and backup tools included as part of the suite, IT administrators have all the tools they need to run an enterprise environment ranging from a few servers to thousands of servers.

In this chapter, you will learn to

Identify the role of each product in the vSphere product suite

Recognize the interaction and dependencies between the products in the vSphere suite

Understand how vSphere differs from other virtualization products

Exploring VMware vSphere 5.5

The VMware vSphere product suite is a comprehensive collection of products and features that together provide a full array of enterprise virtualization functionality. The vSphere product suite includes the following products and features:

VMware ESXi

VMware vCenter Server

vSphere Update Manager

VMware vSphere Client and vSphere Web Client

VMware vCenter Orchestrator

vSphere Virtual Symmetric Multi-Processing

vSphere vMotion and Storage vMotion

vSphere Distributed Resource Scheduler (DRS)

vSphere Storage DRS

Storage I/O Control and Network I/O Control

Profile-driven storage

vSphere High Availability (HA)

vSphere Fault Tolerance (FT)

vSphere Storage APIs for Data Protection and VMware Data Protection

Virtual SAN (VSAN)

vSphere Replication

Flash Read Cache

Rather than waiting to introduce these products and features in their own chapters, we will introduce each product or feature in the following sections. This will allow us to explain how each one affects the design, installation, and configuration of your virtual infrastructure. After we cover the features and products in the vSphere suite, you'll have a better grasp of how each of them fits into the design and the big picture of virtualization.

Certain products outside the vSphere product suite extend the vSphere product line with new functionality. These additional products include VMware Horizon View, VMware vCloud Director, VMware vCloud Automation Center, and VMware vCenter Site Recovery Manager, just to name a few. VMware even offers bundles of vSphere and these other products in the vCloud Suite to make it easier for users to purchase and consume the products in their environments. However, because of the size and scope of these products, they are not covered in this book.

As of the writing of this book, VMware vSphere 5.5 is the latest release of the VMware vSphere product family. This book covers functionality found in version 5.5. Where possible, we've tried to note differences between vSphere 5.0 or 5.1 and vSphere 5.5. For detailed information on VMware vSphere 5.0, refer to Mastering VMware vSphere 5, also published by Sybex (2011). (If you are still running vSphere 4.x, Sybex also offers Mastering VMware vSphere 4 [2009].)

To help simplify navigation and to help you find information on the breadth of products and features in the vSphere product suite, we've prepared Table 1.1, which contains cross-references to where you can find more information about a particular product or feature elsewhere in the book.

Table 1.1 Product and feature cross-references

First we'll look at the actual products that make up the VMware vSphere product suite, and then we'll examine the major features. Let's start with the products in the suite; in particular, let's start with VMware ESXi.

Examining the Products in the vSphere Suite

In the following sections, we'll describe and review the products found in the vSphere product suite.

VMware ESXi

The core of the vSphere product suite is the hypervisor, which is the virtualization layer that serves as the foundation for the rest of the product line. In vSphere 5 and later, including vSphere 5.5, the hypervisor comes in the form of VMware ESXi.

Long-time users of VMware vSphere may recognize this as a shift in the way VMware provides the hypervisor. Prior to vSphere 5, the hypervisor was available in two forms: VMware ESX and VMware ESXi. Although both products shared the same core virtualization engine, supported the same set of virtualization features, leveraged the same licenses, and were considered bare-metal installation hypervisors (also referred to as Type 1 hypervisors; see the sidebar titled Type 1 and Type 2 Hypervisors), there were still notable architectural differences. In VMware ESX, VMware used a Linux-derived Service Console to provide an interactive environment through which users could interact with the hypervisor. The Linux-based Service Console also included services found in traditional operating systems, such as a firewall, Simple Network Management Protocol (SNMP) agents, and a web server.

Type 1 and Type 2 Hypervisors

Hypervisors are generally grouped into two classes: Type 1 hypervisors and Type 2 hypervisors. Type 1 hypervisors run directly on the system hardware and thus are often referred to as bare-metal hypervisors. Type 2 hypervisors require a host operating system, and the host operating system provides I/O device support and memory management. VMware ESXi is a Type 1 bare-metal hypervisor. (In earlier versions of vSphere, VMware ESX was also considered a Type 1 bare-metal hypervisor.) Other Type 1 bare-metal hypervisors include KVM (part of the open-source Linux kernel), Microsoft Hyper-V, and products based on the open-source Xen hypervisor like Citrix XenServer and Oracle VM.

VMware ESXi, on the other hand, is the next generation of the VMware virtualization foundation. Unlike VMware ESX, ESXi installs and runs without the Linux-based Service Console. This gives ESXi an ultralight footprint of approximately 70 MB. Despite the lack of the Service Console, ESXi provides all the same virtualization features that VMware ESX supported in earlier versions. Of course, ESXi 5.5 has been enhanced from earlier versions to support even more functionality, as you'll see in this chapter and in future chapters.

The key reason that VMware ESXi is able to support the same extensive set of virtualization functionality as VMware ESX without the Service Console is that the core of the virtualization functionality wasn't (and still isn't) found in the Service Console. It's the VMkernel that is the foundation of the virtualization process. It's the VMkernel that manages the virtual machines' (VMs') access to the underlying physical hardware by providing CPU scheduling, memory management, and virtual switch data processing. Figure 1.1 shows the structure of VMware ESXi.

Figure 1.1 The VMkernel is the foundation of the virtualization functionality found in VMware ESXi

We mentioned earlier that VMware ESXi 5.5 is enhanced over earlier releases. One such area of enhancement is in the configuration limits of what the hypervisor is capable of supporting. Table 1.2 shows the configuration maximums for the last few versions of VMware ESX/ESXi.

Table 1.2 VMware ESXi maximums

These are just some of the configuration maximums. Where appropriate, future chapters will include additional values for VMware ESXi maximums for network interface cards (NICs), storage, VMs, and so forth.

Given that VMware ESXi is the foundation of virtualization within the vSphere product suite, you'll see content for VMware ESXi throughout the book. Table 1.1, earlier in this chapter, tells you where you can find more information about specific features of VMware ESXi elsewhere in the book.

VMware vCenter Server

Stop for a moment to think about your current network. Does it include Active Directory? There is a good chance it does. Now imagine your network without Active Directory, without the ease of a centralized management database, without the single sign-on capabilities, and without the simplicity of groups. That is what managing VMware ESXi hosts would be like without using VMware vCenter Server. Not a very pleasant thought, is it? Now calm yourself down, take a deep breath, and know that vCenter Server, like Active Directory, is meant to provide a centralized management platform and framework for all ESXi hosts and their respective VMs. vCenter Server allows IT administrators to deploy, manage, monitor, automate, and secure a virtual infrastructure in a centralized fashion. To help provide scalability, vCenter Server leverages a backend database (Microsoft SQL Server and Oracle are both supported, among others) that stores all the data about the hosts and VMs.

In previous versions of VMware vSphere, vCenter Server was a Windows-only application. Version 5.5 of vSphere still offers this Windows-based installation of vCenter Server but also offers a prebuilt vCenter Server Appliance (a virtual appliance, in fact, something you'll learn about in Chapter 10, Using Templates and vApps) that is based on Linux. Having a Linux-based vCenter Server Appliance is a great alternative for organizations that don't wish to deploy a Windows Server instance just to manage the vSphere environment.

vCenter Server not only provides configuration and management capabilities—which include features such as VM templates, VM customization, rapid provisioning and deployment of VMs, role-based access controls, and fine-grained resource allocation controls—it also provides the tools for the more advanced features of vSphere vMotion, vSphere Distributed Resource Scheduler, vSphere High Availability, and vSphere Fault Tolerance. All of these features are described briefly in this chapter and in more detail in later chapters.

In addition to vSphere vMotion, vSphere Distributed Resource Scheduler, vSphere High Availability, and vSphere Fault Tolerance, using vCenter Server to manage ESXi hosts enables a number of other features:

Enhanced vMotion Compatibility (EVC), which leverages hardware functionality from Intel and AMD to enable greater CPU compatibility between servers grouped into vSphere DRS clusters

Host profiles, which allow administrators to bring greater consistency to host configurations across larger environments and to identify missing or incorrect configurations

Storage I/O Control, which provides cluster-wide quality of service (QoS) controls so that administrators can ensure that critical applications receive sufficient I/O resources even during times of congestion

vSphere Distributed Switches, which provide the foundation for networking settings and third-party virtual switches that span multiple hosts and multiple clusters

Network I/O Control, which allows administrators to flexibly partition physical NIC bandwidth and provide QoS for different types of traffic

vSphere Storage DRS, which enables VMware vSphere to dynamically migrate storage resources to meet demand, much in the same way that DRS balances CPU and memory utilization

vCenter Server plays a central role in any sizable VMware vSphere implementation. In Chapter 3, Installing and Configuring vCenter Server, we discuss planning and installing vCenter Server as well as look at ways to ensure its availability. Chapter 3 will also examine the differences between the Windows-based version of vCenter Server and the Linux-based vCenter Server virtual appliance. Because of vCenter Server's central role in a VMware vSphere deployment, we'll touch on vCenter Server in almost every chapter throughout the rest of the book. Refer to Table 1.1 previously in this chapter for specific cross-references.

vCenter Server is available in three packages:

vCenter Server Essentials is integrated into the vSphere Essentials kits for small office deployment.

vCenter Server Standard provides all the functionality of vCenter Server, including provisioning, management, monitoring, and automation.

vCenter Server Foundation is like vCenter Server Standard but is limited to managing three ESXi hosts and does not include vCenter Orchestrator or support for linked-mode operation.

You can find more information on licensing and product editions for VMware vSphere in the section Licensing VMware vSphere.

vSphere Update Manager

vSphere Update Manager is an add-on package for vCenter Server that helps users keep their ESXi hosts and select VMs patched with the latest updates. vSphere Update Manager provides the following functionality:

Scans to identify systems that are not compliant with the latest updates

User-defined rules for identifying out-of-date systems

Automated installation of patches for ESXi hosts

Full integration with other vSphere features like Distributed Resource Scheduler

vSphere Update Manager works with the Windows-based installation of vCenter Server as well as the prepackaged vCenter Server virtual appliance. Refer to Table 1.1 for more information on where vSphere Update Manager is described in this book.

VMware vSphere Web Client and vSphere Client

vCenter Server provides a centralized management framework for VMware ESXi hosts, but it's the vSphere Web Client (and its predecessor, the Windows-based vSphere Client) where vSphere administrators will spend most of their time.

With the release of vSphere 5, VMware shifted its primary administrative interface to a robust new vSphere Web Client. The vSphere Web Client provides a dynamic, web-based user interface for managing a virtual infrastructure and enables vSphere administrators to manage their infrastructure without needing to install the Windows-based vSphere Client on a system. In its initial release, the vSphere Web Client provided a subset of the functionality available to the full Windows-based vSphere Client. However, in subsequent releases—including the 5.5 release—the vSphere Web Client has been enhanced and expanded to include almost all the functionality a vSphere administrator needs to manage a vSphere environment. Further, VMware has stated that the vSphere Web Client will eventually replace the Windows-based vSphere Client entirely. For this reason, we'll use screen shots of the vSphere Web Client throughout this book unless it is impossible to do so.

The Windows-based vSphere Client is still available to allow you to manage ESXi hosts, either directly or through an instance of vCenter Server, but VMware's development efforts are focused on the vSphere Web Client. You can install the vSphere Client by browsing to the URL of an ESXi host or vCenter Server and selecting the appropriate installation link (although keep in mind that Internet access might be required in order to download the client in some instances). The vSphere Client provides a rich graphical user interface (GUI) for all day-to-day management tasks and for the advanced configuration of a virtual infrastructure. While you can connect the vSphere Client either directly to an ESXi host or to an instance of vCenter Server, the full set of management capabilities are available only when you are connecting the vSphere Client to vCenter Server.

As we mentioned earlier, the vSphere Web Client is the stated future direction for VMware vSphere's management interface. For that reason, we focus primarily on how to use the vSphere Web Client throughout this book. Tasks in the vSphere Client should be similar, but note that some tasks can be performed only in the vSphere Web Client, not the Windows-based vSphere Client.

VMware vCenter Orchestrator

VMware vCenter Orchestrator is a workflow automation engine that is automatically installed with every instance of vCenter Server. Using vCenter Orchestrator, vSphere administrators can build automated workflows for a wide variety of tasks available within vCenter Server. The automated workflows you build using vCenter Orchestrator range from simple to complex. VMware also makes vCenter Orchestrator plug-ins to extend the functionality to include manipulating Microsoft Active Directory, Cisco's Unified Computing System (UCS), and VMware vCloud Director. This makes vCenter Orchestrator a powerful tool to use in building automated workflows in the virtualized data center.

Now that we've discussed the specific products in the VMware vSphere product suite, we'd like to take a closer look at some of the significant features.

Examining the Features in VMware vSphere

In the following sections, we'll take a closer look at some of the features that are available in the vSphere product suite. We'll start with Virtual SMP.

vSphere Virtual Symmetric Multi-Processing

The vSphere Virtual Symmetric Multi-Processing (vSMP or Virtual SMP) product allows virtual infrastructure administrators to construct VMs with multiple virtual processors. vSphere Virtual SMP is not the licensing product that allows ESXi to be installed on servers with multiple processors; it is the technology that allows the use of multiple processors inside a VM. Figure 1.2 identifies the differences between multiple processors in the ESXi host system and multiple virtual processors.

Figure 1.2 vSphere Virtual SMP allows VMs to be created with more than one : virtual CPU.

With vSphere Virtual SMP, applications that require and can actually use multiple CPUs can be run in VMs configured with multiple virtual CPUs. This allows organizations to virtualize even more applications without negatively impacting performance or being unable to meet service-level agreements (SLAs).

In vSphere 5, VMware expanded this functionality by also allowing users to specify multiple virtual cores per virtual CPU. Using this feature, a user could provision a dual socket VM with two cores per socket for a total of four virtual cores. This gives users tremendous flexibility in carving up CPU processing power among the VMs.

vSphere vMotion and vSphere Storage vMotion

If you have read anything about VMware, you have most likely read about the extremely useful feature called vMotion. vSphere vMotion, also known as live migration, is a feature of ESXi and vCenter Server that allows an administrator to move a running VM from one physical host to another physical host without having to power off the VM. This migration between two physical hosts occurs with no downtime and with no loss of network connectivity to the VM. The ability to manually move a running VM between physical hosts on an as-needed basis is a powerful feature that has a number of use cases in today's datacenters.

Suppose a physical machine has experienced a nonfatal hardware failure and needs to be repaired. Administrators can easily initiate a series of vMotion operations to remove all VMs from an ESXi host that is to undergo scheduled maintenance. After the maintenance is complete and the server is brought back online, administrators can utilize vMotion to return the VMs to the original server.

Alternately, consider a situation in which you are migrating from one set of physical servers to a new set of physical servers. Assuming that the details have been addressed—and we'll discuss the details around vMotion in Chapter 12, Balancing Resource Utilization—you can use vMotion to move the VMs from the old servers to the newer servers, making quick work of a server migration with no interruption of service.

Even in normal day-to-day operations, vMotion can be used when multiple VMs on the same host are in contention for the same resource (which ultimately is causing poor performance across all the VMs). vMotion can solve the problem by allowing an administrator to migrate any VMs that are facing contention to another ESXi host with greater availability for the resource in demand. For example, when two VMs are in contention with each other for CPU resources, an administrator can eliminate the contention by using vMotion to move one of the VMs to an ESXi host that has more available CPU resources.

vMotion moves the execution of a VM, relocating the CPU and memory footprint between physical servers but leaving the storage untouched. Storage vMotion builds on the idea and principle of vMotion by providing the ability to leave the CPU and memory footprint untouched on a physical server but migrating a VM's storage while the VM is still running.

Deploying vSphere in your environment generally means that lots of shared storage—Fibre Channel or iSCSI SAN or NFS—is needed. What happens when you need to migrate from an older storage array to a newer storage array? What kind of downtime would be required? Or what about a situation where you need to rebalance utilization of the array, either from a capacity or performance perspective?

vSphere Storage vMotion directly addresses these situations. By providing the ability to move the storage for a running VM between datastores, Storage vMotion enables administrators to address all of these situations without downtime. This feature ensures that outgrowing datastores or moving to a new SAN does not force an outage for the affected VMs and provides administrators with yet another tool to increase their flexibility in responding to changing business needs.

vSphere Distributed Resource Scheduler

vMotion is a manual operation, meaning that an administrator must initiate the vMotion operation. What if VMware vSphere could perform vMotion operations automatically? That is the basic idea behind vSphere Distributed Resource Scheduler (DRS). If you think that vMotion sounds exciting, your anticipation will only grow after learning about DRS. DRS, simply put, leverages vMotion to provide automatic distribution of resource utilization across multiple ESXi hosts that are configured in a cluster.

Given the prevalence of Microsoft Windows Server in today's datacenters, the use of the term cluster often draws IT professionals into thoughts of Microsoft Windows Server clusters. Windows Server clusters are often active-passive or active-active-passive clusters. However, ESXi clusters are fundamentally different, operating in an active-active mode to aggregate and combine resources into a shared pool. Although the underlying concept of aggregating physical hardware to serve a common goal is the same, the technology, configuration, and feature sets are quite different between VMware ESXi clusters and Windows Server clusters.

Aggregate Capacity and Single Host Capacity

Although we say that a DRS cluster is an implicit aggregation of CPU and memory capacity, it's important to keep in mind that a VM is limited to using the CPU and RAM of a single physical host at any given time. If you have two ESXi servers with 32 GB of RAM each in a DRS cluster, the cluster will correctly report 64 GB of aggregate RAM available, but any given VM will not be able to use more than approximately 32 GB of RAM at a time.

An ESXi cluster is an implicit aggregation of the CPU power and memory of all hosts involved in the cluster. After two or more hosts have been assigned to a cluster, they work in unison to provide CPU and memory to the VMs assigned to the cluster (keeping in mind that any given VM can only use resources from one host; see the sidebar titled Aggregate Capacity and Single Host Capacity). The goal of DRS is twofold:

At startup, DRS attempts to place each VM on the host that is best suited to run that VM at that time.

While a VM is running, DRS seeks to provide that VM with the required hardware resources while minimizing the amount of contention for those resources in an effort to maintain balanced utilization levels.

The first part of DRS is often referred to as intelligent placement. DRS can automate the placement of each VM as it is powered on within a cluster, placing it on the host in the cluster that it deems to be best suited to run that VM at that moment.

DRS isn't limited to operating only at VM startup, though. DRS also manages the VM's location while it is running. For example, let's say three servers have been configured in an ESXi cluster with DRS enabled. When one of those servers begins to experience a high contention for CPU utilization, DRS detects that the cluster is imbalanced in its resource usage and uses an internal algorithm to determine which VM(s) should be moved in order to create the least imbalanced cluster. For every VM, DRS will simulate a migration to each host and the results will be compared. The migrations that create the least imbalanced cluster will be recommended or automatically performed, depending upon DRS's configuration.

DRS performs these on-the-fly migrations without any downtime or loss of network connectivity to the VMs by leveraging vMotion, the live migration functionality we described earlier. This makes DRS extremely powerful because it allows clusters of ESXi hosts to dynamically rebalance their resource utilization based on the changing demands of the VMs running on that cluster.

Fewer Bigger Servers or More Smaller Servers?

Remember from Table 1.2 that VMware ESXi supports servers with up to 320 logical CPU cores and up to 4TB of RAM. With vSphere DRS, though, you can combine multiple smaller servers for the purpose of managing aggregate capacity. This means that bigger, more-powerful servers might not be better servers for virtualization projects. These larger servers, in general, are significantly more expensive than smaller servers, and using a greater number of smaller servers (often referred to as scaling out) may provide greater flexibility than a smaller number of larger servers (often referred to as scaling up). The key thing to remember is that a bigger server isn't necessarily a better server.

vSphere Storage DRS

vSphere Storage DRS takes the idea of vSphere DRS and applies it to storage. Just as vSphere DRS helps to balance CPU and memory utilization across a cluster of ESXi hosts, Storage DRS helps balance storage capacity and storage performance across a cluster of datastores using mechanisms that echo those used by vSphere DRS.

We described vSphere DRS's feature called intelligent placement, which automates the placement of new VMs based on resource usage within an ESXi cluster. In the same fashion, Storage DRS has an intelligent placement function that automates the placement of VM virtual disks based on storage utilization. Storage DRS does this through the use of datastore clusters. When you create a new VM, you simply point it to a datastore cluster, and Storage DRS automatically places the VM's virtual disks on an appropriate datastore within that datastore cluster.

Likewise, just as vSphere DRS uses vMotion to balance resource utilization dynamically, Storage DRS uses Storage vMotion to rebalance storage utilization based on capacity and/or latency thresholds. Because Storage vMotion operations are typically much more resource intensive than vMotion operations, vSphere provides extensive controls over the thresholds, timing, and other guidelines that will trigger a Storage DRS automatic migration via Storage vMotion.

Storage I/O Control and Network I/O Control

VMware vSphere has always had extensive controls for modifying or controlling the allocation of CPU and memory resources to VMs. What vSphere didn't have prior to the release of vSphere 4.1 was a way to apply these same sort of extensive controls to storage I/O and network I/O. Storage I/O Control and Network I/O Control address that shortcoming.

Storage I/O Control (SIOC) allows vSphere administrators to assign relative priority to storage I/O as well as assign storage I/O limits to VMs. These settings are enforced cluster-wide; when an ESXi host detects storage congestion through an increase of latency beyond a user-configured threshold, it will apply the settings configured for that VM. The result is that VMware administrators can ensure that the VMs that need priority access to storage resources get the resources they need. In vSphere 4.1, Storage I/O Control applied only to VMFS storage; vSphere 5 extended that functionality to NFS datastores.

The same goes for Network I/O Control (NIOC), which provides VMware administrators with more granular controls over how VMs use network bandwidth provided by the physical NICs. As the widespread adoption of 10 Gigabit Ethernet continues, Network I/O Control provides VMware administrators with a way to more reliably ensure that network bandwidth is properly allocated to VMs based on priority and limits.

Profile-Driven Storage

With profile-driven storage, vSphere administrators are able to use storage capabilities and VM storage profiles to ensure that VMs are residing on storage that is able to provide the necessary levels of capacity, performance, availability, and redundancy. Profile-driven storage is built on two key components:

Storage capabilities, leveraging vSphere's storage awareness APIs

VM storage profiles

Storage capabilities are either provided by the storage array itself (if the array is capable of using vSphere's storage awareness APIs) and/or defined by a vSphere administrator. These storage capabilities represent various attributes of the storage solution.

VM storage profiles define the storage requirements for a VM and its virtual disks. You create VM storage profiles by selecting the storage capabilities that must be present for the VM to run. Datastores that have all the capabilities defined in the VM storage profile are compliant with the VM storage profile and represent possible locations where the VM could be stored.

This functionality gives vSphere administrators much greater visibility into storage capabilities and helps ensure that the appropriate functionality for each VM is indeed being provided by the underlying storage.

Refer to Table 1.1 to find out which chapter discusses profile-driven storage in more detail.

vSphere High Availability

In many cases, high availability—or the lack of high availability—is the key argument used against virtualization. The most common form of this argument more or less sounds like this: Before virtualization, the failure of a physical server affected only one application or workload. After virtualization, the failure of a physical server will affect many more applications or workloads running on that server at the same time. We can't put all our eggs in one basket!

VMware addresses this concern with another feature present in ESXi clusters called vSphere High Availability (HA). Once again, by nature of the naming conventions (clusters, high availability), many traditional Windows administrators will have preconceived notions about this feature. Those notions, however, are incorrect in that vSphere HA does not function like a high-availability configuration in Windows. The vSphere HA feature provides an automated process for restarting VMs that were running on an ESXi host at a time of server failure (or other qualifying infrastructure failure, as we'll describe in Chapter 7, Ensuring High Availability and Business Continuity). Figure 1.3 depicts the VM migration that occurs when an ESXi host that is part of an HA-enabled cluster experiences failure.

Figure 1.3 The vSphere HA feature will restart any VMs that were previously running on an ESXi host that experiences server failure.

The vSphere HA feature, unlike DRS, does not use the vMotion technology as a means of migrating servers to another host. vMotion applies only to