Chapter 4: Virtualization & Cloud Computing (220-1201)

4.1 Virtualization Fundamentals

What is Virtualization?

Virtualization allows you to run multiple operating systems (virtual machines) on a single physical computer.

Instead of one computer = one OS
You can have one computer = many virtual systems

Key Benefits:

• Resource efficiency
• Cost savings
• Isolation (safe testing)
• Easy backup and recovery

Virtual Machine (VM)

A software-based computer that behaves like a physical machine.

Components of a VM:

• Virtual CPU
• Virtual RAM
• Virtual disk
• Virtual network adapter

 4.2 Hypervisors (VERY IMPORTANT)

 What is a Hypervisor?

Software that creates and manages virtual machines

 Types of Hypervisors

 Type 1 (Bare Metal)

• Runs directly on hardware
• No host OS

Examples:

• VMware ESXi
• Microsoft Hyper-V

✔ Faster
✔ Used in enterprises

 Type 2 (Hosted)

• Runs on top of an OS

Examples:

• Oracle VM VirtualBox
• VMware Workstation

✔ Easier to use
✔ Ideal for labs (A+ students)

4.3 Virtualization Requirements

 Hardware Requirements

CPU Virtualization Support

• Intel VT-x
• AMD-V

 Must be enabled in BIOS/UEFI

Resource Requirements

• Enough RAM (minimum 8GB recommended)
• Multi-core CPU
• SSD storage (for performance)

Host vs Guest OS

4.4 Virtual Machine Configuration

 VM Settings

• Allocate RAM (e.g., 4GB)
• Assign CPU cores
• Create virtual disk (dynamic or fixed)
• Attach ISO file for OS installation

Disk Types

 Snapshots (CRITICAL)

• Save VM state at a point in time
• Allows rollback after errors

4.5 Virtual Networking

 Network Modes (MEMORIZE)

NAT (Network Address Translation)

• Shares host internet
• VM hidden from network

✔ Easy setup

Bridged Mode

• VM acts like real device
• Gets its own IP

✔ Best for realistic labs

Internal Network

• Isolated VMs only
• No internet

✔ Safe testing environment

 4.6 Cloud Computing Fundamentals

 What is Cloud Computing?

Delivery of computing services over the internet.

Examples:

• Storage
• Servers
• Applications

Key Benefits:

• Scalability
• Accessibility
• Cost efficiency
• High availability

4.7 Cloud Service Models (HIGH PRIORITY)

SaaS (Software as a Service)

• Software delivered via internet
• No installation needed

Examples:

• Microsoft 365
• Google Docs

 PaaS (Platform as a Service)

• Platform for developers
• No hardware management

IaaS (Infrastructure as a Service)

• Virtual servers and networking
• Full control over OS

Comparison

 4.8 Cloud Deployment Models

Public Cloud

• Shared infrastructure
• Accessible over internet

Private Cloud

• Dedicated to one organization

 Hybrid Cloud

• Mix of public + private

4.9 Cloud Concepts

Scalability

• Increase/decrease resources as needed

Elasticity

• Automatic scaling based on demand

High Availability

• Systems stay online (minimal downtime)

 Resource Pooling

• Shared resources across users

4.10 Virtual Desktop Infrastructure (VDI)

 What is VDI?

• Desktop environment hosted on a server
• Accessed remotely

 Benefits:

• Centralized management
• Secure data storage
• Remote access

4.11 Virtualization & Cloud Troubleshooting

 Common Issues

VM Won’t Start

Causes:

• Virtualization disabled
• Not enough RAM

Slow VM Performance

Causes:

• Low resources
• Too many VMs running

No Network in VM

Causes:

• Wrong network mode
• Adapter disabled

Cloud Service Down

Causes:

• Provider outage

4.12 Security in Virtualization & Cloud

 Virtualization Risks:

• VM escape attacks
• Improper isolation

Cloud Security:

• Data encryption
• Access control
• MFA (Multi-Factor Authentication)

 4.13 Exam Tips (CRITICAL)

✔ Know Type 1 vs Type 2 hypervisors
✔ Memorize SaaS, PaaS, IaaS
✔ Understand NAT vs Bridged vs Internal
✔ Know benefits of cloud computing
✔ Understand snapshots and VM basics

Quick Knowledge Check

1. What does a hypervisor do?
   A. Stores data
   B. Manages VMs
   C. Connects networks
   D. Provides internet
2. Which is a Type 2 hypervisor?
   A. ESXi
   B. Hyper-V
   C. VirtualBox
   D. BIOS
3. Which cloud model provides software online?
   A. IaaS
   B. PaaS
   C. SaaS
   D. LAN
4. Which network mode gives VM its own IP?
   A. NAT
   B. Bridged
   C. Internal
   D. Loopback
5. What allows rollback of a VM?
   A. Backup
   B. Snapshot
   C. Clone
   D. Restore point

Answers: 1-B, 2-C, 3-C, 4-B, 5-B