You are previewing Troubleshooting vSphere Storage.
O'Reilly logo
Troubleshooting vSphere Storage

Book Description

All vSphere administrators will benefit big-time from this book because it gives you clear, practical instructions on troubleshooting a whole host of storage problems. From fundamental to advanced techniques, it’s all here.

  • Identify key issues that affect vSphere storage visibility, performance, and capacity

  • Comprehend the storage metrics and statistics that are collected in vSphere

  • Get acquainted with the many vSphere features that can proactively protect your environment

  • In Detail

    Virtualization has created a new role within IT departments everywhere; the vSphere administrator. vSphere administrators have long been managing more than just the hypervisor, they have quickly had to adapt to become a ‘jack of all trades’ in organizations. More and more tier 1 workloads are being virtualized, making the infrastructure underneath them all that more important. Due to this, along with the holistic nature of vSphere, administrators are forced to have the know-how on what to do when problems occur.

    This practical, easy-to-understand guide will give the vSphere administrator the knowledge and skill set they need in order to identify, troubleshoot, and solve issues that relate to storage visibility, storage performance, and storage capacity in a vSphere environment.

    This book will first give you the fundamental background knowledge of storage and virtualization. From there, you will explore the tools and techniques that you can use to troubleshoot common storage issues in today’s data centers.

    You will learn the steps to take when storage seems slow, or there is limited availability of storage. The book will go over the most common storage transport such as Fibre Channel, iSCSI, and NFS, and explain what to do when you can’t see your storage, where to look when your storage is experiencing performance issues, and how to react when you reach capacity. You will also learn about the tools that ESXi contains to help you with this, and how to identify key issues within the many vSphere logfiles.

    Table of Contents

    1. Troubleshooting vSphere Storage
      1. Table of Contents
      2. Troubleshooting vSphere Storage
      3. Credits
      4. About the Author
      5. Acknowledgment
      6. About the Reviewers
        1. Support files, eBooks, discount offers and more
          1. Why Subscribe?
          2. Free Access for Packt account holders
          3. Instant Updates on New Packt Books
      8. Preface
        1. What this book covers
        2. What you need for this book
        3. Who this book is for
        4. Conventions
        5. Reader feedback
        6. Customer support
          1. Errata
          2. Piracy
          3. Questions
      9. 1. Understanding vSphere Storage Concepts and Methodologies
        1. Storage virtualization
        2. Supported filesystems
          1. VMFS
          2. NFS
          3. Raw disk
        3. Storage naming
          1. Viewing device identifiers
            1. Within the vSphere Client
            2. Within ESXi Shell
          2. The many ways vSphere identifies storage
            1. Friendly names
            2. Identifiers
              1. NAA identifiers
              2. T10 identifiers
              3. IQN identifiers
              4. MPX identifiers
            3. Runtime names
        4. The vSphere Pluggable Storage Architecture
          1. Pluggable Storage Architecture (PSA) roles and commands
          2. Multipathing Plugin – the VMware Native Multipathing Plugin roles and commands
          3. Storage Array Type Plugin roles and commands
          4. Path Selection Plugin roles and commands
        5. An I/O request – from start to finish
        6. Summary
      10. 2. Commonly Used Tools for Troubleshooting Storage
        1. The vSphere troubleshooting methodology
        2. vCenter Storage Views (Reports and Maps)
          1. Reports
          2. Maps
        3. Using esxtop/resxtop
          1. Switching displays
          2. Field customization
          3. Refresh interval
        4. Logfiles used in vSphere Storage troubleshooting
          1. ESXi logging
            1. Viewing ESXi logs
          2. vCenter Server logging
          3. Virtual machine logging
        5. Summary
      11. 3. Troubleshooting Storage Visibility
        1. Common storage visibility issues across block transport types
          1. ESXi claim rules and LUN masking
          2. Troubleshooting paths and path selection
          3. vCenter Server Storage filters
          4. Disk resignaturing
          5. LUN numbering
        2. Troubleshooting Fibre Channel storage visibility
          1. Registered State Change Notification (RSCN)
          2. Identifying and interpreting Fibre Channel connection issues in the logs
        3. Troubleshooting IP storage visibility
          1. Verifying network connectivity to our iSCSI and NFS array
          2. iSCSI and NFS port requirements
          3. CHAP authentication
          4. Identifying and interpreting iSCSI storage connection issues in the logs
          5. Troubleshooting NFS storage
            1. NFS ACLs
            2. NFS permissions
          6. Identifying and interpreting NFS storage connection issues in the logs
        4. Summary
      12. 4. Troubleshooting Storage Contention
        1. Identifying storage contention and performance issues
          1. Disk adapter latency statistics
          2. Disk device latency statistics
          3. Virtual machine latency statistics
          4. Using vCenter alarms to monitor latency
          5. Planning – how to properly scale your storage
            1. Calculating IOPs requirements
            2. Calculating the number of disks required
              1. How do we know when we need more IOPs?
              2. vSphere features to help with latency, contention, placement, and compliance
                1. Profile-Driven Storage
                2. Storage DRS for performance
              3. SCSI reservation conflicts
                1. Monitoring SCSI reservation conflicts with esxtop
                2. Resolving excessive SCSI resolutions
              4. Storage queuing in vSphere
                1. OS queue
                2. Adapter queue
                3. Per-LUN queue
                4. Viewing queues in ESXi
                5. vSphere Storage I/O Control
                  1. Configuring Storage I/O Control
              5. Troubleshooting NAS/iSCSI storage performance
                1. iSCSI port binding and Round Robin path policy
                2. Jumbo Frames and MTU size
              6. Summary
      13. 5. Troubleshooting Storage Capacity and Overcommitment
        1. Monitoring datastore usage
        2. Thin Provisioning
          1. Array thin provisioning
          2. Hypervisor (VMDK) thin provisioning
          3. Monitoring Thin Provisioning
        3. Snapshots
          1. Understanding vSphere Snapshots
          2. Monitoring snapshot disk usage
        4. Datastore file management
        5. Virtual machine swap files
        6. Increasing the size of our datastores
          1. Growing a VMFS datastore
          2. Adding an extent to a VMFS datastore
        7. Balancing capacity with Storage DRS
        8. Summary
      14. A. Troubleshooting Steps
        1. You cannot connect to your iSCSI storage
          1. Have all the network requirements for your iSCSI connection been met?
          2. Various things to check on ESXi
          3. Have all CHAP requirements been met?
          4. Has there been any advanced settings dealing with iSCSI incorrectly configured?
          5. Further check the logs for iSCSI-related errors
        2. You cannot connect to your NFS storage
          1. Have all the network requirements for you NFS connection been met?
          2. Check the settings on your NFS array
          3. Has there been any advanced settings dealing with NFS incorrectly configured?
          4. Further check the logs for NFS related errors
        3. You cannot connect to your Fibre Channel Storage
          1. Fibre Channel switch zoning
          2. Check paths to storage array/PSP
          3. Various things to check on ESXi
          4. Check the storage array
          5. Further check the logs for Fibre Channel related errors
        4. My storage/virtual machine is slow
          1. Inspect latency values to further pinpoint where performance degradation is occurring
          2. Ensure that your storage array is handling the demand
      15. B. Statistics of esxtop
        1. Overview of esxtop's interactive commands
          1. Activating different displays
          2. Field selection
          3. Field order
          4. Filtering and sorting the displayed objects
          5. Other useful information
        2. esxtop statistics
      16. C. iSCSI Error Codes
        1. Interpreting software iSCSI error codes
      17. Index