VMware ESXi 5.0 Installation and RWC2 Tips and Tricks White Paper

Introduction to VMware ESXi

1. Introduction to VMware ESXi

1.1 What is VMware ESX?

VMware ESX is an enterprise-level computer virtualization product offered by VMware, Inc. ESX

is a component of VMware’s larger offering, VMware infrastructure, and adds management and

reliability services to the core server product. In the ESX original architecture, the virtualization

kernel (VMKernel) is augmented with a Linux Operating System known as Service console (also

known as COS or service console) to provide management interface such as executing script or

installing third party agents into the host. Various VMware management agents are deployed in

the Console OS, along with other infrastructure service agents such as name service, time

service. In this architecture, many customers deploy other agents from 3rd parties to provide

particular functionality, such as hardware monitoring and system management. Furthermore,

individual admin users log into the Console OS to run configuration and diagnostic commands

and scripts.

1.2 What is VMware ESXi?

In 2007, VMware introduced ESXi to deliver industry-leading performance and scalability while

setting a new bar for reliability, security and hypervisor management efficiency. VMware ESXi is

a smaller and free footprint verision of ESX, it uses the same kernel to deliver virtualization

capabilities but doesn’t include ESX’s Service Console and all of the VMware agents run directly

on the VMKernel. Only modules that have been digitally signed by VMware are allowed on the

system, creating a tightly locked-down architecture. Preventing arbitrary code from running on

the ESXi host greatly improves the security of the system. ESXi is a “bare-metal” hypervisor,

meaning it installs directly on top of the physical server and partition it into multiple virtual

mechines that can run simultaneously, sharing the physical resources of the underlying server.

1.3 Comparation between ESX and ESXi

For ESX:

 VMware agents run in Console OS.

 Nearly all other management functionality provided by agents running in the Console OS.

 Users must log into Console OS in order to run commands for configuration and

diagnostics.

For ESXi:

 VMware agents ported to run directly on VMKernel.

 Authorized 3rd party modules can also run in Vmkernel. These provide specific

functionality like hardware monitoring and hardware drivers.

 VMware components and third party components can be updated independently.

 The “dual-image” approach lets you revert to prior image if desired.

 Other capabilities necessary for integration into an enterprise datacenter are provided

natively.

 No other arbitrary code is allowed on the system.

1.4 Why do we need ESXi?

Thanks to its ultra-thin architecture with less than 100MB of code-base disk footprint, ESXi

deliver the insdustry-leading performance and scalability of ESX with several additional benefits