This book consists of more than 200 pages about the two most important key features of VMware vSphere: the VMware High Availability (HA) and the VMware Distributed Resource Scheduler (DRS). The first part of the book concentrates on the HA and gives you an excellent explanation how the HA works, what are the pre-requisites needed for HA, the concept of primary and secondary nodes. The isolation response and detection, the admission control mechanisms as well as the impact of the chosen admission control policy and of course, the VM Monitoring feature which is, as stated in the book “the bridge between the virtualization layer and the application layer”.
The second part of the book gives you detailed information about the DRS and explains in depth how the resource management works. It provides the cluster settings and automation level overview, when the DRS is invoked and how the recommendations are calculated. It describes the concept of resource pools, shares, CPU/Memory reservations and limits as well as the impact of the reservations and limits in the vSphere environment. Last chapter of the book is dedicated to VMware Distributed Power Management (DPM). This chapter gives you a good understanding of how the decisions are calculated and evaluated when DPM powers a host on or off.
This is just a small summary of the main topics of the VMware vSphere 4.1 HA and DRS technical deepdive book. Believe me, there is a lot more. What I really like is the basic design principle quotes. They become handy when you are designing or building a new virtual infrastructure. All the basic design principles are bundled in the appendix A of the book.
So, to summarize the VMware vSphere 4.1 HA and DRS technical deepdive book I would say that the authors did a really excellent job by putting their experience and brains together to write this great book. The book is understandable and easy to read when you have some experience with VMware vSphere. The topics are provided with illustrations and diagrams that clarify the more complex sub-topics. This book is a “must read” for everyone who is working with VMware vSphere environment and I would highly recommend this book to any Administrator, System Engineer, Consultant or an IT Architect. You can order your copy of the book at Amazon or at ComCol.