Chapter 4. ESX: The Brawn Behind the Brains
At the heart of your VMware Infrastructure 3 is your ESX. ESX servers, referred to as ESX hosts, manage the sharing of resources between your virtual machines. Every option that VMware offers builds on your ESX host foundation.
This chapter covers the parts that make up ESX and how they work together to provide you with a stable and scalable virtual environment. This includes everything from the design of an ESX host and building for fault-tolerance to picking the right hardware to meet your needs.
Checking Out ESX Host Anatomy
ESX is one of the best written pieces of software I have seen. Before going further, a quick distinction needs to be made: ESX is an operating system (two actually) and ESX hosts are server hardware that is running the ESX operating systems. ESX offers rock-solid reliability and can truly drive down your computing costs. It does this through a combination of well-written software and thoroughly tested hardware. And VMware is the industry leader, setting the trends and direction for virtualization while the rest of the players play catch up. Figure 4-1 shows the relationship between ESX hosts and virtual machines.
Figure 4-1. The relationship between ESX hosts and virtual machines.
One host is never enough
I can not stress this enough: Hardware failure is not a matter of if it will happen: It is a matter of when