Book Image

Learning VMware vSphere

By : Rebecca Fitzhugh, Abhilash G B
Book Image

Learning VMware vSphere

By: Rebecca Fitzhugh, Abhilash G B

Overview of this book

Computer virtualization is a method to enable the running of multiple application workloads on a machine to achieve efficient utilization and reduce the number of physical machines in a data center. This has now become the foundation of many modern day data centers. What began as a technology to virtualize x86 architecture has now grown beyond the limits of a server’s hardware and into the realm of storage and network virtualization. VMware is currently the market leader in developing data center virtualization solutions. This book goes into the details of designing and implementing VMware solutions that form the foundation of a VMware infrastructure. The book begins by introducing you to the concepts of server virtualization followed by the architecture of VMware’s hypervisor – ESXi and then by its installation and configuration. You then learn what is required to manage a vSphere environment and configure advanced management capabilities of vCenter. Next you are taken through topics on vSphere Networking, Storage, ESXi Clustering, Resource Management and Virtual Machine Management. You will then be introduced to SSL Certificate Management and its use in a vSphere environment. Finally, you will learn about the lifecycle management of a vSphere environment by effectively monitoring, patching and upgrading vSphere components using Update Manager. By the end of the book, you will know how to use VMware’s vSphere suite of components to lay the foundation of a modern day virtual infrastructure.
Table of Contents (18 chapters)
Learning VMware vSphere
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface

Managing VMFS snapshots


Storage array management tools allow us to clone/snapshot/replicate LUN/s backing VMFS datastore/s. The snapshots are created at the storage array using the array management interface. However, it is not possible to mount an identical copy of an existing VMFS datastore to the same ESXi host. This is deliberately disallowed to avoid data corruption, unless it is backed by a different device ID.

ESXi identifies each VMFS volume using its signature denoted by a UUID (Universally Unique Identifier). The UUID is generated when the volume is first created or resignatured and is stored in the LVM header of the VMFS volume.

The command esxcli storage filesystem list can be used to list all the VMFS datastores along with their details, which include the UUID, in columnar format as follows:

The following diagram shows the structure of a VMFS UUID:

When an ESXi host scans for new LUN devices and VMFS volumes on it, it compares the physical device ID (NAA ID) of the LUN with...