THE BASICS OF VIRTUALIZATION

THE BASICS OF VIRTUALIZATION

1. Introduction

   • “A VM is a tightly isolated software container that runs its own operating system and applications as if it were a physical computer.”

2. How Servers Work?

   • A server, like most computers, is a collection of specialized hardware resources that are accessed by a software OS through a series of specialized drivers.
   • These resources can be many things, but commonly consist of the following: CPU processor RAM (or memory) Storage NIC

3. Hypervisors

   • A hypervisor is piece of software that sits between the OS and the server’s specialized hardware resources. When in place, it’s the hypervisor, rather than the OS, that manages the connections between the drivers and the server’s resources.
   • A hypervisor can present a virtual connection to the server’s resources for a VM’s OS. What’s significant, though, is that it can do it for a lot of VMs all running on the same server, even if those VMs all have different operating systems and unrelated applications.
   • Types of Hypervisors
     • There are two types of hypervisors, denoted as Type 1 and Type 2.
       • A Type 1 hypervisor is called a bare-metal hypervisor in reference to the fact that the hypervisor runs directly on the server hardware without any native operating system.
       • Type 2 hypervisors, called hosted hypervisors, run on top of a native OS. In this use case, the hypervisor is a shim that sits between the OS of the VM above and the OS of the server or computer below.
   • A hypervisor is an operating system for operating systems.
   • A hypervisor is a Virtual Machine (VM) Monitor

4. Benefits of Virtual Machines

   • Reduced Cost
   • Less Space
   • Availability and Flexibility
   • Faster Application Spin-Up
   • Easier Access for Development

5. Hypervisor Vendors

   • KVM
   • XEN
   • VMware ESXi
   • Microsoft Hyper-V