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

Snapshots


Another valuable VMware vSphere feature is virtual machine snapshots. Snapshots give us the ability to capture point in time restore points on a virtual machine which can be utilized to test things such as upgrades, patch installations, and general configuration changes. If something were to go terribly wrong during our tests, snapshots give us the ability to failback or go to these points in time, the known good states.

Snapshots are often used in backup scenarios as well, where a snapshot will be taken to free up the underlying disk in order for it to be backed up or replicated. However, along with all of these benefits comes the drawback of the risk of a snapshot filling up a datastore if not closely monitored. To understand this, we will first look at what happens when a snapshot is taken.

Understanding vSphere Snapshots

A snapshot of a VM creates several new files on our datastore explained as follows:

  • .vmsd: It contains information about the snapshot

  • .vmsm: It contains a point...