Home > Store

Essential Virtual SAN (VSAN): Administrator's Guide to VMware Virtual SAN, 2nd Edition

Register your product to gain access to bonus material or receive a coupon.

Essential Virtual SAN (VSAN): Administrator's Guide to VMware Virtual SAN, 2nd Edition


  • This product currently is not for sale.
Not for Sale


  • Copyright 2016
  • Dimensions: 7" x 9-1/8"
  • Pages: 368
  • Edition: 2nd
  • Book
  • ISBN-10: 0-13-451166-2
  • ISBN-13: 978-0-13-451166-5

Plan, implement, and manage VMware’s radically simple, enterprise-class software-defined storage platform

VMware’s Virtual SAN has rapidly proven itself in environments ranging from hospitals to oil rigs to e-commerce platforms. Along the way, it has matured to offer unsurpassed features for data integrity, availability, and space efficiency. Virtual SAN 6.x makes all-flash storage practical for even more use cases, while radically simplifying IT operations and supporting the transition to hyper-converged infrastructures (HCI). Now, the authors of Essential Virtual SAN (VSAN) have thoroughly updated their definitive guide to this transformative technology. Writing for vSphere administrators, architects, and consultants, Cormac Hogan and Duncan Epping explain what Virtual SAN is, how it has evolved, what it now offers, and how to gain maximum value from it.


Hogan and Epping draw on unsurpassed experience shaping Virtual SAN and helping VMware customers deploy it. They offer expert insight into preparation, installation, configuration, policies, provisioning, clusters, and more. You’ll also find practical guidance for using its new Health and Performance Services to gain end-to-end visibility into infrastructure and resource consumption. Both an up-to-the-minute reference and hands-on tutorial, Essential Virtual SAN, Second Edition uses realistic examples to demonstrate the immense power of Virtual SAN 6.x. You’ll learn all you need to successfully plan and deploy the newest versions, and operate them smoothly and efficiently.



  • Understanding the goals and concepts of Software-Defined Storage and Virtual SAN
  • Meeting updated requirements for safe Virtual SAN 6.x implementation
  • Architecting, installing, and configuring Virtual SAN for your unique environment
  • Simplifying deployment with VM storage policies and provisioning
  • Controlling availability, performance, and reliability
  • Efficiently managing and maintaining Virtual SAN
  • Providing resiliency and scale-out storage functionality
  • Designing and sizing clusters (with examples)
  • Using stretched clusters to address rigorous downtime requirements
  • Applying valuable new features such as deduplication, compression, checksums, and encryption
  • Using Health and Performance Services to troubleshoot hardware, configurations, and performance


Author's Site

Visit the authors' sites at CormacHogan.com and yellow-bricks.com.

Sample Content

Online Sample Chapter

VM Storage Policies on VSAN

Sample Pages

Download the sample pages (includes Chapter 4 and Index)

Table of Contents

Foreword by Christos Karamanolis xvii

About the Author xix

About the Technical Reviewers xxi

Acknowledgments xxiii

We Want to Hear from You! xxv

1 Introduction to VSAN 1

    Software-Defined Datacenter 1

    Software-Defined Storage 2

    Hyper-Convergence/Server SAN Solutions 3

    Introducing Virtual SAN 4

    What Is Virtual SAN? 6

    What Does VSAN Look Like to an Administrator? 9

    Summary 12

2 VSAN Prerequisites and Requirements for Deployment 13

    VMware vSphere 13

        ESXi 14

        Cache and Capacity Devices 14

        ESXi Boot Considerations 15

    VSAN Requirements 15

        VMware Hardware Compatibility Guide 16

        VSAN Ready Nodes 16

        Storage Controllers 17

        Capacity Tier Devices 19

        Cache Tier Devices 21

    Network Requirements 22

        Network Interface Cards 22

        Supported Virtual Switch Types 22

        Layer 2 or Layer 3 23

        VMkernel Network 23

        VSAN Network Traffic 24

        Jumbo Frames 24

        NIC Teaming 25

        Network I/O Control 25

    VSAN Stretched Cluster 25

    VSAN 2-Node Remote Office/Branch Office (ROBO) 26

        Firewall Ports 26

    Summary 26

3 VSAN Installation and Configuration 29

    VSAN Networking 29

    VMkernel Network for VSAN 30

    VSAN Network Configuration: VMware Standard Switch 31

    VSAN Network Configuration: vSphere Distributed Switch 32

        Step 1: Create the Distributed Switch 32

        Step 2: Create a Distributed Port Group 33

        Step 3: Build VMkernel Ports 34

    Possible Network Configuration Issues 38

    Network I/O Control Configuration Example 40

    Design Considerations: Distributed Switch and Network I/O Control 42

        Scenario 1: Redundant 10 GbE Switch Without “Link Aggregation” Capability 43

        Scenario 2: Redundant 10 GbE Switch with Link Aggregation Capability 45

    Creating a VSAN Cluster 48

    vSphere HA 49

        vSphere HA Communication Network 49

        vSphere HA Heartbeat Datastores 50

        vSphere HA Admission Control 50

        vSphere HA Isolation Response 51

        vSphere HA Component Protection 51

    The Role of Disk Groups 51

        Disk Group Maximums 52

        Why Configure Multiple Disk Groups in VSAN? 52

        Cache Device to Capacity Device Sizing Ratio 53

        Automatically Add Disks to VSAN Disk Groups 54

        Manually Adding Disks to a VSAN Disk Group 55

        Disk Group Creation Example 55

        VSAN Datastore Properties 58

    Summary 59

4 VM Storage Policies on VSAN 61

    Introducing Storage Policy-Based Management in a VSAN Environment 62

        Number of Failures to Tolerate 65

        Failure Tolerance Method 66

        Number of Disk Stripes Per Object 69

        IOPS Limit for Object 70

        Flash Read Cache Reservation 71

        Object Space Reservation 71

        Force Provisioning 71

        Disable Object Checksum 73

    VASA Vendor Provider 73

        An Introduction to VASA 73

        Storage Providers 74

    VSAN Storage Providers: Highly Available 75

        Changing VM Storage Policy On-the-Fly 75

        Objects, Components, and Witnesses 80

    VM Storage Policies 80

        Enabling VM Storage Policies 81

        Creating VM Storage Policies 81

        Assigning a VM Storage Policy During VM Provisioning 81

    Summary 82

5 Architectural Details 83

    Distributed RAID 83

    Objects and Components 86

        Component Limits 87

        Virtual Machine Storage Objects 88

        Namespace 89

        Virtual Machine Swap 90

        VMDKs and Deltas 90

        Witnesses and Replicas 90

        Object Layout 91

    VSAN Software Components 94

        Component Management 95

        Data Paths for Objects 95

        Object Ownership 96

        Placement and Migration for Objects 96

        Cluster Monitoring, Membership, and Directory Services 97

        Host Roles (Master, Slave, Agent) 97

        Reliable Datagram Transport 98

    On-Disk Formats 98

        Cache Devices 99

        Capacity Devices 99

    VSAN I/O Flow 100

        Caching Algorithms 100

        The Role of the Cache Layer 100

        Anatomy of a VSAN Read on Hybrid VSAN 102

        Anatomy of a VSAN Read on All-Flash VSAN 103

        Anatomy of a VSAN Write on Hybrid VSAN 103

        Anatomy of a VSAN Write on All-Flash VSAN 104

        Retiring Writes to Capacity Tier on Hybrid VSAN 105

        Deduplication and Compression 105

        Data Locality 107

        Data Locality in VSAN Stretched Clusters 108

    Storage Policy-Based Management 109

    VSAN Capabilities 109

        Number of Failures to Tolerate Policy Setting 110

        Best Practice for Number of Failures to Tolerate 112

        Stripe Width Policy Setting 113

        RAID-0 Used When No Striping Specified in the Policy 117

        Stripe Width Maximum 119

        Stripe Width Configuration Error 120

        Stripe Width Chunk Size 121

        Stripe Width Best Practice 122

        Flash Read Cache Reservation Policy Setting 122

        Object Space Reservation Policy Setting 122

        VM Home Namespace Revisited 123

        VM Swap Revisited 123

        How to Examine the VM Swap Storage Object 124

        Delta Disk / Snapshot Caveat 126

        Verifying How Much Space Is Actually Consumed 126

        Force Provisioning Policy Setting 127

        Witnesses and Replicas: Failure Scenarios 127

        Data Integrity Through Checksum 130

        Recovery from Failure 131

        Problematic Device Handling 134

        What About Stretching VSAN? 134

    Summary 135

6 VM Storage Policies and Virtual Machine Provisioning 137

    Policy Setting: Number of Failures to Tolerate = 1 137

    Policy Setting: Failures to Tolerate = 1, Stripe Width = 2 144

    Policy Setting: Failures to Tolerate = 2, Stripe Width = 2 148

    Policy Setting: Failures to Tolerate = 1, Object Space Reservation = 50% 152

    Policy Setting: Failures to Tolerate = 1, Object Space Reservation = 100% 155

    Policy Setting: RAID-5 157

    Policy Setting: RAID-6 158

    Policy Setting: RAID-5/6 and Stripe Width = 2 159

    Default Policy 160

    Summary 164

7 Management and Maintenance 165

    Health Check 165

        Health Check Tests 165

        Proactive Health Checks 167

        Performance Service 168

    Host Management 169

        Adding Hosts to the Cluster 169

        Removing Hosts from the Cluster 170

        ESXCLI VSAN Cluster Commands 171

    Maintenance Mode 172

        Default Maintenance Mode/Decommission Mode 175

        Recommended Maintenance Mode Option for Updates and Patching 175

    Disk Management 177

        Adding a Disk Group 177

        Removing a Disk Group 178

        Adding Disks to the Disk Group 179

        Removing Disks from the Disk Group 180

    Wiping a Disk 182

        Blinking the LED on a Disk 183

        ESXCLI VSAN Disk Commands 184

    Failure Scenarios 185

        Capacity Device Failure 185

        Cache Device Failure 186

        Host Failure 187

        Network Partition 188

        Disk Full Scenario 193

    Thin Provisioning Considerations 194

    vCenter Management 195

        vCenter Server Failure Scenario 196

        Running vCenter Server on VSAN 196

        Bootstrapping vCenter Server 197

    Summary 199

8 Stretched Cluster 201

    What is a Stretched Cluster? 201

    Requirements and Constraints 203

    Networking and Latency Requirements 205

    New Concepts in VSAN Stretched Cluster 206

    Configuration of a Stretched Cluster 208

    Failure Scenarios 216

    Summary 224

9 Designing a VSAN Cluster 225

    Ready Node Profiles 225

    Sizing Constraints 227

    Cache to Capacity Ratio 228

    Designing for Performance 229

        Impact of the Disk Controller 231

    VSAN Performance Capabilities 235

    Design and Sizing Tools 236

    Scenario 1: Server Virtualization–Hybrid 237

        Determining Your Host Configuration 238

    Scenario 2–Server Virtualization–All-flash 241

    Summary 244

10 Troubleshooting, Monitoring, and Performance 245

    Health Check 246

        Ask VMware 246

        Health Check Categories 247

        Proactive Health Checks 253

    ESXCLI 256

        esxcli vsan datastore 256

        esxcli vsan network 257

        esxcli vsan storage 258

        esxcli vsan cluster 262

        esxcli vsan faultdomain 263

        esxcli vsan maintenancemode 264

        esxcli vsan policy 264

        esxcli vsan trace 267

        Additional Non-ESXCLI Commands for Troubleshooting VSAN 268

    Ruby vSphere Console 275

        VSAN Commands 276

        SPBM Commands 300

    Troubleshooting VSAN on the ESXi 303

        Log Files 304

        VSAN Traces 304

        VSAN VMkernel Modules and Drivers 305

    Performance Monitoring 305

        Introducing the Performance Service 305

        ESXTOP Performance Counters for VSAN 308

        vSphere Web Client Performance Counters for VSAN 309

        VSAN Observer 310

    Sample VSAN Observer Use Case 316

    Summary 318

TOC, 9780134511665, 5/10/2016



Submit Errata

More Information

Pearson IT Certification Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Pearson IT Certification and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Pearson IT Certification products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.pearsonitcertification.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020