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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