virt 101 - Day Two: Virtualization and x86 CPU Architecture

Welcome to day two of the virtualization 101 series. We will explore how server virtualization works, and the basics of x86 CPU architecture.
How does server virtualization work?

In a virtual machine,  computations are performed using a physical CPU, memory, and disk storage – although in some cases the amount  of resources presented to the virtual machine does not really exist. There are various techniques used to optimize actual physical resource utilization.

virt 101 - Day One: Introduction

Welcome to my virtualization 101 series of blog posts. This will introduce x86 server virtualization at a high level, and dig deeper into specific concepts. I will be posting regular updates in this series, and feedback is welcome.

Here are some of the concepts and terms that will be considered:

• Server Virtualization vs. Cloud Computing vs. Emulation
• When was virtualization introduced?
• How does virtualization work?
• x86 CPU Architecture
• Binary Translation
• Paravirtualization
• Hardware Assisted Virtualization
• Virtualized Memory Management
• Extended Page Tables or Nested Page Tables
• Virtualized I/O and Devices
• Benefits and Challenges of Virtualization

the DIY home VPN experiment (part three - my virtualized OpenVPN server)

Part Three: My Virtualized OpenVPN Server

Overview

In this post, I'd like to share my most recent home lab project - a nested OpenVPN server. I refer to it as nested, because it is running completely within my desktop computer. See the illustration below.

The idea for this project came along when I working on setting up a VPN with my older Linksys router. Basically, I wanted to come up with a way to run a home lab VPN server without requiring any additional hardware, and I wanted to incorporate virtualization into this project. In addition, running it as a VM allows for fairly safe and controlled experimentation, without running the risk of bricking one's router with non-standard firmware.