O'Reilly logo

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Essential Virtual SAN (VSAN): Administrator’s Guide to VMware® Virtual SAN, Second Edition

Book Description

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

  • Table of Contents

    1. About This E-Book
    2. Title Page
    3. Copyright Page
    4. Dedication Page
    5. Contents
    6. Foreword by Christos Karamanolis
    7. About the Authors
    8. About the Technical Reviewers
    9. Acknowledgments
    10. We Want to Hear from You!
    11. Reader Services
    12. Introduction
      1. You, the Reader
      2. How to Use This Book
    13. Chapter 1. Introduction to VSAN
      1. Software-Defined Datacenter
      2. Software-Defined Storage
      3. Hyper-Convergence/Server SAN Solutions
      4. Introducing Virtual SAN
      5. What Is Virtual SAN?
      6. What Does VSAN Look Like to an Administrator?
      7. Summary
    14. Chapter 2. VSAN Prerequisites and Requirements for Deployment
      1. VMware vSphere
        1. ESXi
        2. Cache and Capacity Devices
        3. ESXi Boot Considerations
      2. VSAN Requirements
        1. VMware Hardware Compatibility Guide
        2. VSAN Ready Nodes
        3. Storage Controllers
        4. Capacity Tier Devices
        5. Cache Tier Devices
      3. Network Requirements
        1. Network Interface Cards
        2. Supported Virtual Switch Types
        3. Layer 2 or Layer 3
        4. VMkernel Network
        5. VSAN Network Traffic
        6. Jumbo Frames
        7. NIC Teaming
        8. Network I/O Control
      4. VSAN Stretched Cluster
      5. VSAN 2-Node Remote Office/Branch Office (ROBO)
        1. Firewall Ports
      6. Summary
    15. Chapter 3. VSAN Installation and Configuration
      1. VSAN Networking
      2. VMkernel Network for VSAN
      3. VSAN Network Configuration: VMware Standard Switch
      4. VSAN Network Configuration: vSphere Distributed Switch
        1. Step 1: Create the Distributed Switch
        2. Step 2: Create a Distributed Port Group
        3. Step 3: Build VMkernel Ports
      5. Possible Network Configuration Issues
      6. Network I/O Control Configuration Example
      7. Design Considerations: Distributed Switch and Network I/O Control
        1. Scenario 1: Redundant 10 GbE Switch Without “Link Aggregation” Capability
        2. Scenario 2: Redundant 10 GbE Switch with Link Aggregation Capability
      8. Creating a VSAN Cluster
      9. vSphere HA
        1. vSphere HA Communication Network
        2. vSphere HA Heartbeat Datastores
        3. vSphere HA Admission Control
        4. vSphere HA Isolation Response
        5. vSphere HA Component Protection
      10. The Role of Disk Groups
        1. Disk Group Maximums
        2. Why Configure Multiple Disk Groups in VSAN?
        3. Cache Device to Capacity Device Sizing Ratio
        4. Automatically Add Disks to VSAN Disk Groups
        5. Manually Adding Disks to a VSAN Disk Group
        6. Disk Group Creation Example
        7. VSAN Datastore Properties
      11. Summary
    16. Chapter 4. VM Storage Policies on VSAN
      1. Introducing Storage Policy-Based Management in a VSAN Environment
        1. Number of Failures to Tolerate
        2. Failure Tolerance Method
        3. Number of Disk Stripes Per Object
        4. IOPS Limit for Object
        5. Flash Read Cache Reservation
        6. Object Space Reservation
        7. Force Provisioning
        8. Disable Object Checksum
      2. VASA Vendor Provider
        1. An Introduction to VASA
        2. Storage Providers
      3. VSAN Storage Providers: Highly Available
        1. Changing VM Storage Policy On-the-Fly
        2. Objects, Components, and Witnesses
      4. VM Storage Policies
        1. Enabling VM Storage Policies
        2. Creating VM Storage Policies
        3. Assigning a VM Storage Policy During VM Provisioning
      5. Summary
    17. Chapter 5. Architectural Details
      1. Distributed RAID
      2. Objects and Components
        1. Component Limits
        2. Virtual Machine Storage Objects
        3. Namespace
        4. Virtual Machine Swap
        5. VMDKs and Deltas
        6. Witnesses and Replicas
        7. Object Layout
      3. VSAN Software Components
        1. Component Management
        2. Data Paths for Objects
        3. Object Ownership
        4. Placement and Migration for Objects
        5. Cluster Monitoring, Membership, and Directory Services
        6. Host Roles (Master, Slave, Agent)
        7. Reliable Datagram Transport
      4. On-Disk Formats
        1. Cache Devices
        2. Capacity Devices
      5. VSAN I/O Flow
        1. Caching Algorithms
        2. The Role of the Cache Layer
        3. Anatomy of a VSAN Read on Hybrid VSAN
        4. Anatomy of a VSAN Read on All-Flash VSAN
        5. Anatomy of a VSAN Write on Hybrid VSAN
        6. Anatomy of a VSAN Write on All-Flash VSAN
        7. Retiring Writes to Capacity Tier on Hybrid VSAN
        8. Deduplication and Compression
        9. Data Locality
        10. Data Locality in VSAN Stretched Clusters
      6. Storage Policy-Based Management
      7. VSAN Capabilities
        1. Number of Failures to Tolerate Policy Setting
        2. Best Practice for Number of Failures to Tolerate
        3. Stripe Width Policy Setting
        4. RAID-0 Used When No Striping Specified in the Policy
        5. Stripe Width Maximum
        6. Stripe Width Configuration Error
        7. Stripe Width Chunk Size
        8. Stripe Width Best Practice
        9. Flash Read Cache Reservation Policy Setting
        10. Object Space Reservation Policy Setting
        11. VM Home Namespace Revisited
        12. VM Swap Revisited
        13. How to Examine the VM Swap Storage Object
        14. Delta Disk / Snapshot Caveat
        15. Verifying How Much Space Is Actually Consumed
        16. Force Provisioning Policy Setting
        17. Witnesses and Replicas: Failure Scenarios
        18. Data Integrity Through Checksum
        19. Recovery from Failure
        20. Problematic Device Handling
        21. What About Stretching VSAN?
      8. Summary
    18. Chapter 6. VM Storage Policies and Virtual Machine Provisioning
      1. Policy Setting: Number of Failures to Tolerate = 1
      2. Policy Setting: Failures to Tolerate = 1, Stripe Width = 2
      3. Policy Setting: Failures to Tolerate = 2, Stripe Width = 2
      4. Policy Setting: Failures to Tolerate = 1, Object Space Reservation = 50%
      5. Policy Setting: Failures to Tolerate = 1, Object Space Reservation = 100%
      6. Policy Setting: RAID-5
      7. Policy Setting: RAID-6
      8. Policy Setting: RAID-5/6 and Stripe Width = 2
      9. Default Policy
      10. Summary
    19. Chapter 7. Management and Maintenance
      1. Health Check
        1. Health Check Tests
        2. Proactive Health Checks
        3. Performance Service
      2. Host Management
        1. Adding Hosts to the Cluster
        2. Removing Hosts from the Cluster
        3. ESXCLI VSAN Cluster Commands
      3. Maintenance Mode
        1. Default Maintenance Mode/Decommission Mode
        2. Recommended Maintenance Mode Option for Updates and Patching
      4. Disk Management
        1. Adding a Disk Group
        2. Removing a Disk Group
        3. Adding Disks to the Disk Group
        4. Removing Disks from the Disk Group
      5. Wiping a Disk
        1. Blinking the LED on a Disk
        2. ESXCLI VSAN Disk Commands
      6. Failure Scenarios
        1. Capacity Device Failure
        2. Cache Device Failure
        3. Host Failure
        4. Network Partition
        5. Disk Full Scenario
      7. Thin Provisioning Considerations
      8. vCenter Management
        1. vCenter Server Failure Scenario
        2. Running vCenter Server on VSAN
        3. Bootstrapping vCenter Server
      9. Summary
    20. Chapter 8. Stretched Cluster
      1. What is a Stretched Cluster?
      2. Requirements and Constraints
      3. Networking and Latency Requirements
      4. New Concepts in VSAN Stretched Cluster
      5. Configuration of a Stretched Cluster
      6. Failure Scenarios
      7. Summary
    21. Chapter 9. Designing a VSAN Cluster
      1. Ready Node Profiles
      2. Sizing Constraints
      3. Cache to Capacity Ratio
      4. Designing for Performance
        1. Impact of the Disk Controller
      5. VSAN Performance Capabilities
      6. Design and Sizing Tools
      7. Scenario 1: Server Virtualization—Hybrid
        1. Determining Your Host Configuration
      8. Scenario 2—Server Virtualization—All-flash
      9. Summary
    22. Chapter 10. Troubleshooting, Monitoring, and Performance
      1. Health Check
        1. Ask VMware
        2. Health Check Categories
        3. Proactive Health Checks
      2. ESXCLI
        1. esxcli vsan datastore
        2. esxcli vsan network
        3. esxcli vsan storage
        4. esxcli vsan cluster
        5. esxcli vsan faultdomain
        6. esxcli vsan maintenancemode
        7. esxcli vsan policy
        8. esxcli vsan trace
        9. Additional Non-ESXCLI Commands for Troubleshooting VSAN
      3. Ruby vSphere Console
        1. VSAN Commands
        2. SPBM Commands
      4. Troubleshooting VSAN on the ESXi
        1. Log Files
        2. VSAN Traces
        3. VSAN VMkernel Modules and Drivers
      5. Performance Monitoring
        1. Introducing the Performance Service
        2. ESXTOP Performance Counters for VSAN
        3. vSphere Web Client Performance Counters for VSAN
        4. VSAN Observer
      6. Sample VSAN Observer Use Case
      7. Summary
    23. Index
    24. Code Snippets