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

Virtual machine swap files


Every time a virtual machine is powered on, a swap file (.vswp) is created. Swap files are utilized by ESXi to swap memory in and out of the disk in case of contention. Swap files affect capacity due to the fact that they are the same size of the memory allocated to that virtual machine, minus any reservations configured.

Tip

The .vswp files are unique to ESXi and used only for hypervisor functions, that is, they are different from those memory techniques that are applied from within the guest OS, such as the swap partition for Linux and the page file for Windows.

As we know, the configuration maximums continue to grow in each and every new release of ESXi, with the current version allowing a rather substantial 1 TB of memory to be assigned to a single virtual machine. If we have deployed this amount of RAM to a VM (with no memory reservation), then we would also end up with a 1 TB swap file on our datastores. This extra swap file consumption is often overlooked during...