Book Review: Virtualization: A Manager’s Guide

Book Review: Virtualization: A Manager’s Guide by Dan Kusnetzky: Publisher- O'Reilly: ISBN- 13: 978-1449306458

First I am thankful of O’Reilly of providing me free copy of book before publication.

As title of book suggests, this book is not for techie. This thoughts is further reinforced by intended audience section of book.

Virtualization: A Manager’s Guide is pretty short and very lucid and easy read. Book covers virtualization model developed by author ( or his company) which seems to be pretty good.

The definition of virtualization given by book “Virtualization can create the artificial view that many computers are a single computing resource or that a single machine is really many individual computers” is very correct as most of the definition ignore the many computer part.

I am not going to keep this book in not bookshelf as this lacks technical rigor but certainly it is useful for someone who is not very technical but faces technical staff.

Disclaimer: I did not get paid to review this book, and I do not stand to gain anything if you buy the book. I have no relationship with the publisher or the author.

One can get more information about book and related topics from:

1. Amazon: http://www.amazon.com/Virtualization-Managers-Guide-Dan-Kusnetzky/dp/1449306454
2. Publisher -- http://oreilly.com/catalog/0636920020417
3. Review: http://smoothtommy.wordpress.com/2011/07/05/book-review-virtualization-a-managers-guide/
4. One more review: http://santoshonsoftware.blogspot.com/2011/07/book-review-virtualization-managers.html
5. Third Review: http://mohamedazar.wordpress.com/2011/06/25/virtualization-a-managers-guide/
6. Dan Kusnetzky: http://www.kusnetzky.net/

Virtualization Taxonomy

Revelation about IaaS

While discussing cloud with my colleagues, one revelation comes to me. Infrastructure as Service dimension of cloud is just better access of Data Center. A Data Center which offers its administrative activities as API and supports virtualization.

Virtualization Explained

Virtualization represents any type of process obfuscation where a process is removed from its physical operating environment.

Because of this broad definition, virtualization can almost be applied to any and all parts of IT assets. For example, mobile device emulators are a form of virtualization because the hardware platform normally required to run the mobile operating system has been emulated, removing the OS binding from the hardware it was written for.

But for the real life perspective virtualization can be classified as:

Operating System Virtualization

This is the most prevalent form of virtualization because of the need of running multiple operating systems on a single hardware.

In this form of virtualization, Virtual Machine Managers (VMMs) manage each virtual machine individually on a host operating system (some time directly on hardware). In turn each Virtual Machine hosts a separate instance of operating system. Each of these separate operating systems instances is unaware of the other.

Application Server Virtualization

Application Server Virtualization is just glamorous name of advance load balancing specifically of reverse proxy.

This is an example of one-to-many virtualization: one server is presented to the world, hiding the availability of multiple servers behind a reverse proxy.

Application Virtualization

Application virtualization can be of three types. One way is using Thin Client – browser based access to application. The second one is Zero Client – remote access of machine which hosts application via remote access mechanism. The third approach involves mechanism where application is hosted at remote machine but is executed locally.

Hardware Virtualization

Hardware virtualization has roots in parallel processing. With advent of multi processing hardware and multi core processor it has become omni present in business.

Hardware virtualization breaks up pieces and locations of physical hardware into independent segments and manages those segments as separate, individual components.

Storage Virtualization

Storage virtualization can be broken up into two general types: block virtualization and file virtualization.
Block virtualization is best summed up by Storage Area Network (SAN) and Network Attached Storage (NAS) technologies: distributed storage networks that appear to be single physical devices.

File virtualization moves the virtual layer up into the more human-consumable file and directory structure level. Most file virtualization technologies sit in front of storage networks and keep track of which files and directories reside on which storage devices, maintaining global mappings of file locations.

Service Virtualization
Service virtualization is like catch all case for all of the above definitions. Service virtualization connects all of the components utilized in delivering a service over the network.

In SOA service virtualization is confined to software aspect only is primarily achieved using ESB.