Not all VMs are the same. Some of them are used for business-critical workloads, some of them might be used for internal workloads, and some of the might be only some development and test VMs, and because of that, you want to treat them differently.

You should guarantee that your critical line-of-business application has some resources that are always available, but on the other hand, that your development and test VMs will never consume more than a certain amount of resources.

The most straightforward way to manage the resources of VMs is reservations, limits, and shares. We have already touched on these topics in previous chapters when we talked about network I/O control, but let's have a look at them in more detail.