VM rightsizing

Remember the story in Chapter 4, Performance Monitoring, where you got blamed for a non-performing VM?

Well, part of it was your fault. You meddled with someone else's business.

Many IaaS teams are eager to help application teams downsize the VM. The number one reason is to save the company money. However, this approach is wrong. You need to approach it with respect to benefit, not cost.

There are some tips you can give your customers and policies you can set to encourage VM rightsizing from the beginning.

For a start, keep the building blocks simple—one VM, one OS, one application, and one instance. So, avoid doing things such as having one OS running the web, app, and DB server or one Microsoft SQL server running five instances of databases. The workload can become harder to predict as you cannot isolate them.

Implement a chargeback model that encourages the right behavior (for example, non-linear costing, where an eight-vCPU VM is charged more than eight times the...