Pat Ouellette: What are the application costs associated with vSphere on a per-application basis?
Eric Siebert: On a per-application basis, you have to look at the whole virtualization architecture from the storage level, to the networking level, to the server level and then the software itself that you'd need, such as VMware software, management or administration software. To get a per-application cost, you'd have to extrapolate from all of the associated costs with virtualization. Basically, take a percentage of how much of that application you're using in a virtual environment. There's no easy formula for doing that. You have to add everything up and calculate a cost based on everything that your customer spent on virtualization.
Ouellette: Can you give an example of the cost calculation process for a particular application?
Siebert: Sure. Let's say you're going to implement Lotus Domino in a virtual environment. To calculate the application costs, you would basically add the cost of the servers, any additional storage you [would] need for the servers, and the licenses that you'd need for running the virtualization software. If you're going to use any advanced features, you're going to get different licenses that cost more, and that would be an added cost.
In a lot of cases, an application is usually licensed by either a core or CPU socket. So once you install that application, if it's the sole application that's running on that server, then it's probably going to add up to all the costs that you've put into that server. To calculate that, if you were using maybe 10% of the usage on that virtual server, and you're using the virtual server for other applications, then you would probably just take 10% of that total.
Each software app is different because a lot of them have different resource requirements. Exchange, Domino, SQL have pretty heavy resource requirements. There are some types of chargeback utilities you could also use that measure those types of resource requirements so that you can get a good example of what amount of resources that particular application on that virtual machine is using. You'll also get a better understanding of the cost of that application compared to the other applications running on that server.
About the expert
Eric Siebert is a 25-year IT veteran whose primary focus is VMware virtualization and Windows server administration. He is one of the 300 vExperts named by VMware Inc. for 2009. He is the author of the book VI3 Implementation and Administration and a frequent TechTarget contributor. In addition, he maintains vSphere-land.com, a VMware information site.
This was first published in May 2010