Book Image

vSphere High Performance Cookbook - Second Edition - Second Edition

By : Kevin Elder, Christopher Kusek, Prasenjit Sarkar
Book Image

vSphere High Performance Cookbook - Second Edition - Second Edition

By: Kevin Elder, Christopher Kusek, Prasenjit Sarkar

Overview of this book

vSphere is a mission-critical piece of software for many businesses. It is a complex tool, and incorrect design and deployment can create performance related issues that can negatively affect the business. This book is focused on solving these problems as well as providing best practices and performance-enhancing techniques. This edition is fully updated to include all the new features in version 6.5 as well as the latest tools and techniques to keep vSphere performing at its best. This book starts with interesting recipes, such as the interaction of vSphere 6.5 components with physical layers such as CPU, memory, and networking. Then we focus on DRS, resource control design, and vSphere cluster design. Next, you’ll learn about storage performance design and how it works with VMware vSphere 6.5. Moving on, you will learn about the two types of vCenter installation and the benefits of each. Lastly, the book covers performance tools that help you get the most out of your vSphere installation. By the end of this book, you will be able to identify, diagnose, and troubleshoot operational faults and critical performance issues in vSphere 6.5.
Table of Contents (17 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Performance impact of queuing on the storage array and host


There are several storage queues:

  • Device driver queue
  • Kernel queue
  • Storage array queue

The device driver queue is used for low-level interaction with the storage device. This queue controls the number of active commands that can be on an LUN at the same time. This number is effectively the concurrency of the storage stack. If you set the device queue to 1, then each storage command becomes sequential.

The kernel queue is an overflow queue for the device driver queues. This queue enables features that optimize storage (it doesn't include them; they are built using the queue). These features include multipathing for failover and load balancing, prioritization of storage activities, which is based on VM and cluster shares, and optimizations to improve the efficiency of long sequential operations.

Here's an example of this: batching several incoming read requests and doing 1, 4-7, and 14 hashes together because they're all on nearby parts...