This is a question that has been bothering me for a while, and I can't seem to find anything online that talks about it. I have a server running VMware Hypervisor ESXi. When I boot up virtual machines on it, they usually take 2-3 minutes to boot up; not a terribly long time, but not instantaneous. However, when I look at the performance logs on the server, neither processor, RAM, or disk usage is around 100%; usually they average around 60%-80% So if the server has work to do, why doesn't it do it at 100%?
It seems to me that at any given moment, the component that is limiting performance should run at 100%. For example, if I have a really slow hard drive, then it should almost always run at 100%. Therefore, at least one of the areas (processor, RAM, disk, and network) should always be at 100%, unless the server is at a complete idle.
Why isn't this the case?