VMware® Infrastructure 3 FOR DUMMIES®

Chapter 14. Swimming in Resource Pools

VMware is designed to use computer hardware more efficiently. Just like anything else, though, this becomes too much of a good thing at some point. If you keep adding virtual machines without increasing the available hardware, you eventually have hardware contention: Suddenly there will not be enough CPU, memory, network, or disk resources available to support all of your virtual machines at the same time.

In this chapter, we first look at what resource pools can do for you. Next, we examine how resource pools work their magic. Finally, we discuss setting up and using resource pools.

Sharing and Playing Nicely with Resource Pools

Hardware contention really becomes a "race" condition. You need more memory than you physically have, or you need more CPU cycles than you physically have. By default, all virtual machines get more-or-less equal hardware access, but you can manually tilt the scale in favor of some machines at the expense of others. The way to do this is with resource pools.

Understanding what resource pools do

Tilting the scale in favor of some machines reminds me of the old airline joke about what to do if the oxygen masks fall from the ceiling when you're in a plane:

1. Put the mask on yourself first.

2. If you have a child with you, put her mask on after yours.

3. If you have more than one child with you, decide which one you like best!

Likewise, resource pools let you favor some virtual machines over others. Although folks argue that test and production ...