Book Image

Troubleshooting vSphere Storage

By : Mike Preston
Book Image

Troubleshooting vSphere Storage

By: Mike Preston

Overview of this book

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 (16 chapters)
Troubleshooting vSphere Storage
Credits
About the Author
Acknowledgment
About the Reviewers
www.PacktPub.com
Preface
Index

You cannot connect to your Fibre Channel Storage


The following are some questions and tasks you can take to troubleshoot Fibre Channel connection issues.

Fibre Channel switch zoning

Tip

You can refer Chapter 3, Troubleshooting Storage Visibility, for more information on this topic.

Ensure that your WWNs on your HBAs have been correctly zoned to see the Fibre Channel storage array.

Check paths to storage array/PSP

Tip

You can refer Chapter 1, Understanding vSphere Storage Concepts and Methodologies, for more information on this topic.

The following items need to be considered when checking path to storage array:

  • Ensure that the correct Path Selection Policy has been selected for the type of storage array that you are using:

    • VMW_PSP_FIXED: Default for active-active arrays

    • VMW_PSP_MRU: Default for active-passive arrays

  • To list your currently loaded PSP, use the following command:

    esxcli storage nmp device list
    

Various things to check on ESXi

Tip

You can refer Chapter 3, Troubleshooting Storage Visibility, for more information on this topic.

The following items need to be checked on ESXi:

  • Ensure that no claim rules have been added to the ESXi runtime utilizing the MASK_PATH plug-in. The following command will list your claim rules:

    esxcli storage core claimrule list
    
  • Ensure that LUN ID is set to a number below 255. Also, check the Disk.MaxLun advanced setting ensuring that your LUN ID isn't higher than the value configured.

Check the storage array

Some storage arrays will implement soft zoning and ways to mask LUNs from hosts. Check your storage array to ensure that the LUNs are all presented to the ESXi hosts.

Further check the logs for Fibre Channel related errors

Tip

You can refer Chapter 3, Troubleshooting Storage Visibility, for more information on this topic.

The following items need to be considered when checking logs for Fibre Channel related errors:

  • We can further view any Fibre Channel related errors in the logs by grepping the entire log folder with the following command. You may need to filter out any entries relating to iSCSI.

    grep –r SCSI /var/log/* | less
    
  • Verbose logging can be enabled for troubleshooting purposes by setting the bit values on the following advance settings.

    • Scsi.LogCmdErrors

    • Scsi.LogScsiAborts