ToutVirtual Enterprise Virtualization - A Proper Virtual World

Engineering By Fact? Select A Type Of Virtualization?

October 3rd, 2007

Virtualization?  What The Heck Is That? - Chapter 04

Virtualization is not a simple concept, in this series introducing virtualization, we have discussed what the various types of virtualization are. How to identify what you don’t know, so you know what to look for in a virtualization solution. Even discussed how total cost of ownership can be impacted by virtualization. Thus, virtualization is not a simple concept. However, the day has arrived, now the time has come to pick a virtualization strategy.  Now is the time to implement. Most important, now is the time to not fall in love with it, implement it, and then realize it is not quite what you expected. Never, commit a true crime, ignore results. Virtualization is what it is, nothing more, and nothing less.

Yes, money must be spend, time spent, and results must be evaluated. Virtualization is a commitment, no doubt. Providing the initial scale was sufficient to provide valid results, say, a few host servers, although for some, even on server is enough, just how many virtual instances can you run per host? How many hosts will you need per site? How will you backup the instances sufficient to your archive needs, and disaster recovery needs?  What can be virtualized? What can not be? The horizontal and vertical scale of virtualization is appropriate for your situation? Watch out, this is all results driven, or it better be, and what do you do when the results cost real money?

This is why the concept of engineering by fact must be the corner stone of your defense. Yes, defense, you management is already addicted; they are just itching to scale up and out, only one problem.  They want more virtual instances per host, they want more bang for the buck. In fact, they do not want to honor the results. Just about everyone at the front end of virtualization scaling will say, come on, this is just not rationale, and yet, just about everyone on the back-end of the virtualization, is saying, oh wow, you bet it happens. For the sake of discussion, a given company proved that given a specific set of hardware, it could host ten (10) virtual instances per virtual host, taking into account network IO, disk IO, memory loading, and CPU loading, in fact after 18 months, the results prove with proper tuning of the virtual hosts, twelve (12) virtual instances makes factual sense.  Ok, engineering by fact, 10 to 12 instances, based on rock solid data. End-users are happy, engineering team feels good; operations team feels wonderful because they do not feel like they are sitting under the sword of Damocles.

What happens? Senior management states they must have twenty-five (25) virtual instances per host, or virtualization is not profitable! When the engineering team states that they had done engineering by fact, evaluated real data both from lab, and actual production results for trending load analysis, and even had positive end-user experience as long as no more than 12 virtual instances are used per host, and then asks where in the world did 25 instances per host come from? Management says, because we want it. Want to guess how many times this same senior management will ask why 25 instances was not possible? Engineering by fact, not doing it, is just plain insane.

Entry Filed under: A Proper Virtual World