virtualization basics

Virtualization Overview

Module 1

Prerequisites

System administration experience on Microsoft Windows or Linux operating systems

Good knowledge on Networking and TCP/IP

Knowledge on Storage technology (optional)

Introduction to Virtualization

Objective

Understand the concept of virtualization

Identify the benefits of using virtual machine

Describe scenarios for using virtualization

What is Virtualization

Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device or network resources

Virtualization is a technique for hiding the physical characteristics of computing resources to simplify the way in which other systems, applications, or end users interact with those resources.

Virtualization lets a single physical resource (such as a server, an operating system, an application, or storage device) appear as multiple logical resources

or

Making multiple physical resources (such as storage devices or servers) appear as a single logical resource

What is virtualization

Virtualization is a technology that transforms hardware into software.

Virtualization allows you to run multiple operating systems as virtual machines on a single computer

Copy of an O.S is installed into each virtual machine.

Virtualization is not

• Simulation

• Emulation

Computers in 1990s

Fast Forward to the 1990s

Intel/AMD servers are now very popular (known as “x86” servers)

Each server runs Operating Systems such as Microsoft, Linux, or Netware

Companies put ONE operating system & ONE application on each server

2 servers would grow to 6 servers, eventually to 50 or more servers!

Electricity and space (footprint) becomes a problem….

FileServer

WebServer

FileServer Web

Server

FileServer

DomainServerApp

Server

DNSServer

Each Server Running 1 Application

Computers in 2000s

Fast Forward to the 2000s

Manufacturers “to the rescue”!

Focus on making servers small

“Rack” form factors (6-20 servers per cabinet)

“Blade” form factors (30-60 servers per cabinet)

Space/footprint problem helped….some

Electricity and heat still a problem

Example Dell “Rack” Servers

Example HP “Blade” Servers

• As Servers Got Faster…– Server utilization became even lower– Average server utilization ranges between 4 -10%– STILL one application per server

Today’s IT Challenges

Continued Server Sprawl

Power, space and cooling costs represent one of the largest IT budget line items

One-application-per-server approach leads to complexity and high costs of equipment and administration

Low Server Utilization Rates

Result in excessive acquisition and maintenance costs

What this Equates to Today:

Typical Dev/Test Infrastructure is an IT Headache

Server sprawl – under desks, in closets

Aging, cast-off hardware

Dirty systems – inability to maintain “clean state”

Users and IT bogged down in provisioning requests

Release management is resource intensive and error-prone

*Actual customer photos*Actual customer photos

Virtualization is the Key

Apply Mainframe Virtualization Concepts to Intel / AMD Servers: Use virtualization software to partition an Intel / AMD server to work with several operating system and application “instances”

Oracle SQL Application Servers Email File Print DNS Domain

Deploy several “virtual machines”on one server using groundbreaking

virtualization software

Virtualization Layer Explored

Virtualization Layer - Compatibility

A virtual machine is compatible with standard x86 operating systems such as Windows and Linux

A virtual machine has a motherboard, CPU, memory, disk and network just like a physical server

Applications developed for the standard OS’s will work on a virtual machine

No adjustments are needed to run applications on virtual servers

Virtualization Layer - Isolation

Virtual machines on the same physical machine run independently

They are protected from each other

Virtual Hardware

Virtualization Basics

System without Virtualization Software

System with Virtualization Software

The Basics of Virtualization

The Basics of Virtualization

Virtualization Basics

Before Virtualization:

• Single OS image per machine

• Software and hardware tightly coupled

• Running multiple applications on same machine often creates conflict

• Underutilized resources

• Inflexible and costly infrastructure

After Virtualization:

• Hardware-independence of operating system and applications

• Virtual machines can be provisioned to any system

• Can manage OS and application as a single unit by encapsulating them into virtual machines

How does virtualization work

Virtualization allows multiple operating system instances to run concurrently on a single computer within virtual machines.

A virtualization layer creates the virtual machines.

The virtualization layer is implemented through either a hosted or a bare-metal hypervisor architecture.

Virtualization Approaches

Hosted Virtualization

A virtualization approach where partitioning and virtualization services run on top of a standard operating system (the host).

In this approach, the virtualization software relies on the host operating system to provide the services to talk directly to the underlying hardware.

Hypervisor

A thin layer of software that generally provides virtual partitioning capabilities which runs directly on hardware, but underneath higher-level virtualization services.

Sometimes referred to as a “bare metal” approach.

Virtualization Approaches

Hosted Architecture

Installs and runs as an application

Relies on host OS for device support and physical resource management

Virtualization Using a Bare-Metal Hypervisor

VMware ESX™/ESXi use a hypervisor architecture.

A bare-metal hypervisor system does not require an operating system. The hypervisor is the operating system.

Virtual Machines Explored

Virtual Machines

A virtual machine is a collection of software that has been translated into files

These files are collected and organized in “containers”

These containers can be moved in seconds from one physical machine to another in case of physical server failure or performance needs.

Virtual machines have all the same hardware resources available such as CPU, memory, disk, and network

What is a Virtual Machine?

From the user’s perspective, it is a software platform that, like a physical computer, runs an operating system and applications.

From the hypervisor’s perspective, it is a discrete set of files. These are the main files:

Configuration file

Virtual disk file

NVRAM settings file

Log file

Virtual Machine

Why Use Virtual Machines?

Easy to move and copy:

Encapsulated into files

Independent of physical hardware

Easy to manage:

Isolated from other virtual machines running on the same physical hardware

Insulated from physical hardware changes

Virtual MachinePhysical Machine

Difficult to move or copy

Bound to a specific set of hardware components

Often has short life cycle

Requires personal contact to upgrade hardware

Virtualization benefits

Infrastructure is what connects resources to your business.

Virtual Infrastructure is a dynamic mapping of your resources to your business.

Result: decreased costs and increased efficiencies and responsiveness

Hardware-independence

Server isolation

Highly portable

Security

Administration

TCO and ROI

Virtualization Benifits

Using virtualization solutions, enterprise IT managers can address challenges that include:

Server Consolidation and Containment

Test and Development Optimization

Business Continuity

Enterprise Desktop

Key Features of Virtualization

Encapsulation• All information about a system is stored as data on disk

• Entire systems can be protected with data protection tools

Hardware-Independence• Reliably recover a virtual machine to any hardware

• Enable waterfalling of equipment to recovery site

Resource Pooling• Transparently share and allocate hardware resources

• Automatic resource optimization

Partitioning and Consolidation

• Reduced hardware requirements at production and DR site

• Can use higher consolidation ratios at DR site