Introduction to IoT - Lecture 6: Virtualization

Virtualization

Virtualization is the process of creating a virtual version of hardware platforms, operating systems, storage, or network resources. It provides a layer of abstraction between computing resources and the applications using them. Key benefits include:

• Running multiple OS instances on one physical machine
• Improved IT throughput and cost efficiency through resource pooling

Before and After Virtualization

Before Virtualization

• Single OS image per machine
• Software and hardware tightly coupled
• Running multiple applications on the 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

Virtualization Terminologies

• Virtual Machine (VM): Software emulation of a physical machine with its own virtual hardware.
• Guest OS: Operating system installed on a VM.
• Virtual Machine Monitor (VMM): Sits between the host OS and hypervisor, sometimes part of the hypervisor.
• Hosted Virtualization: Virtualization services run on a conventional OS.
• Hypervisor: Software that enables virtualization by managing VMs and hardware access.

Virtualization Architecture

A layered structure:

• Physical Hardware
• Virtualization Layer
• Virtual Hardware
• Virtual Machines

Types of Hypervisors

• Type 1 (Bare-metal or Native): Runs directly on hardware. Examples:
  • VMware ESXi
  • Microsoft Hyper-V
  • Citrix XenServer (Xen)
  • KVM
• Type 2 (Hosted): Runs on a traditional OS. Examples:
  • VMware Workstation Player
  • Microsoft Virtual PC
  • Oracle VirtualBox

Criteria	Type 1 Hypervisor	Type 2 Hypervisor
Runs on	Bare metal (no OS)	Conventional OS
Virtualization Type	Hardware-level	OS-level
Speed	Faster	Slower
Security	More secure	Less secure
System Independence	Direct hardware access	Limited hardware access
Scalability	Better	Limited

Benefits of Virtualization

• Resource sharing reduces cost
• VM isolation
• Encapsulation of computing environments
• Hardware independence
• Portability of VMs

Levels of Virtualization

• Application-level (JVM, Panot, .NET)
• Library-level (WINE, WABI, vCU)
• OS-level (Jail, FVM, Ensim's)
• Hardware Abstraction Layer (HAL) level (VMware, Virtual PC, VirtualBox)
• Instruction Set Architecture (ISA) level (QEMU, BIRD, Dynamo)

Containers

• Lightweight OS-level virtualization
• Packages code and dependencies
• Share host OS kernel
• Faster boot times and smaller footprint compared to VMs

Virtualization vs. Containerization

Aspect	Virtual Machines	Containers
OS Support	Full OS per VM	Shared host OS kernel
Resource Usage	Heavy, requires significant CPU, memory, storage.	Light, minimal overhead.
Startup Time	Slower (minutes) due to OS boot.	Faster (seconds) as no OS boot is needed.
Isolation	Strong, each VM has its own OS.	Weaker, shares OS but isolates apps.
Use Case	Multi-OS, legacy apps	Microservices, cloud-native apps
Portability	Less portable due to full OS dependency.	Highly portable with app and dependencies.
Example	VMware VMs.	Docker containers.

Summary: VMs are robust and isolated but resource-intensive, while containers are efficient and fast.

Distributed Computing

Models

• Peer-to-Peer Computing
• Cluster Computing
• Grid Computing
• Cloud Computing
  • Fog Computing
  • Edge Computing

Cloud Computing

Cloud computing delivers computing services (e.g., servers, storage, databases) over the internet using a pay-as-you-go model.

Benefits

• Cost reduction
• Universal access
• Software always up-to-date
• Flexibility and scalability
• Big data support

Deployment Models

• Public Cloud
• Private Cloud
• Hybrid Cloud
• Community Cloud

Service Models

• IaaS (Infrastructure as a Service): Provides virtualized computing resources (e.g., servers, storage, networking)
• PaaS (Platform as a Service): Offers a platform for developing, testing, and deploying applications without managing underlying infrastructure.
• SaaS (Software as a Service): Delivers fully functional software applications over the internet on a subscription basis.

Layered Architecture

Typically includes:

• Infrastructure Layer
• Platform Layer
• Application Layer

Advantages

• 24/7 access to data
• Eliminates physical storage requirements
• Easily scalable and maintainable
• No local hardware/software installation
• Instant updates and maintenance

Disadvantages

• Reduced control over data and infrastructure
• Security and privacy rely on the provider

Cloud Computing Open Source Tools Timeline

• OpenNebula
• Eucalyptus
• CloudStack
• OpenStack
• Kubernetes (for container orchestration)

Role of Cloud Computing in IoT

1. Remote Computing Capabilities: Eliminates reliance on on-prem infrastructure.
2. Security & Privacy: Automation reduces threat surfaces.
3. Data Integration: Centralized processing and analysis from distributed IoT sources.
4. Minimal Hardware Dependency: Cloud-based hosting allows for plug-and-play solutions.