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Virtualization Fundamentals

🔹 What is Virtualization?

Virtualization is the process of creating a virtual version of something — like a server,

storage device, operating system, or network resources — instead of using physical
hardware directly.

It allows one physical system (like a computer or server) to run multiple virtual
systems, called virtual machines (VMs).

🔹 Key Concepts:

1. Virtual Machine (VM):

o A software-based computer that runs an operating system and apps like a

physical machine.

o Each VM is isolated and independent.

2. Hypervisor:

o Software that allows virtualization.

o It manages and runs multiple VMs on a single physical machine.

3. Host Machine:

o The actual physical machine where virtualization happens.

4. Guest Machine:

o The virtual machine that runs on the host.

🔹 Types of Hypervisors:

1. Type 1 (Bare-Metal):

o Installed directly on hardware.

o Example: VMware ESXi, Microsoft Hyper-V, Xen.

o Used in data centers and enterprise setups.

Runs directly on the physical hardware.

No host OS required.

Examples: VMware ESXi, Microsoft Hyper-V, Citrix XenServer.

✅ Pros:

 High performance and security.

 Direct access to hardware.

❌ Cons:

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  Requires a dedicated machine.

 Harder to set up for beginners.

2. Type 2 (Hosted):

o Runs on a host OS like any other software.

o Example: VirtualBox, VMware Workstation.

o Used in personal and development environments.

Runs on top of a host OS like a normal application.

Examples: VMware Workstation, VirtualBox, Parallels.

✅ Pros:

 Easy to install and use.

 Ideal for testing and development.

❌ Cons:

 Lower performance.

 Less secure due to dependency on host OS.

Virtualization – Enabling Technology for Cloud Computing

🔹 What Does It Mean?

Virtualization is the foundation or core technology that powers cloud computing.

It enables cloud providers to offer scalable, flexible, and efficient computing
resources over the internet.

🔹 How Virtualization Enables Cloud Computing:

1. Resource Sharing:

o Virtualization allows multiple virtual machines (VMs) to run on a single

physical server.

o This helps cloud providers share resources efficiently among many

users.

2. On-Demand Provisioning:

o With virtualization, new VMs (servers or apps) can be created instantly.

o This supports the on-demand nature of cloud computing.

3. Isolation:

o Each virtual machine runs independently.

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 o This ensures security and isolation, even if multiple users use the same
physical hardware.

4. Scalability:

o Virtual environments can be scaled up or down easily based on user

needs.

o Cloud platforms use this feature to offer flexible services.

5. Cost Efficiency:

o Virtualization reduces the need for physical hardware.

o Helps cloud providers cut costs and offer services at lower prices.

6. Disaster Recovery & Backup:

o Virtual machines can be easily backed up, moved, or restored.

o Makes cloud services reliable and resilient.

7. Automation and Management:

o Tools like hypervisors help in automating VM creation and management.

o Cloud platforms automate services using virtualization at the backend.

🔹 Real-World Example:

Imagine a cloud provider like Amazon Web Services (AWS) or Google Cloud.
They use virtualization to run hundreds of virtual servers on fewer physical
machines.
Each user gets a separate virtual server, even though it might be running on the
same machine.

Types of Virtualization
1. Application Virtualization

2. Network Virtualization

3. Desktop Virtualization

4. Storage Virtualization

5. Server Virtualization

6. Data virtualization

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1. Application Virtualization: Application virtualization enables remote access by
which users can directly interact with deployed applications without installing them on
their local machine. Your personal data and the applications settings are stored on the
server, but you can still run it locally via the internet. It’s useful if you need to work
with multiple versions of the same software. Common examples include hosted or
packaged apps.

Example: Microsoft Azure lets people use their applications without putting them on
their own computers. Once this application is setup in the cloud then employees can
use it from any device, like a laptop or tablet. It feels like the application is on their
computer, but it’s really running on Azure’s servers. This makes things easier, faster,
and safer for the company

2. Network Virtualization: This allows multiple virtual networks to run on the same
physical network, each operating independently. You can quickly set up virtual
switches, routers, firewalls, and VPNs, making network management more flexible and
efficient.

Example: Google Cloud is an example of Network Virtualization. Companies create

their own networks using software instead of physical devices with the help of Google
Cloud. They can set up things like IP addresses, firewalls, and private connections all
in the cloud. This makes it easy to manage, change, and grow their network without
buying any hardware. It saves time, money, and gives more flexibility.

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3. Desktop Virtualization: Desktop virtualization is a process in which you can
create different virtual desktops that users can use from any device like laptop, tablet.
It’s great for users who need flexibility, as it simplifies software updates and provides
portability.

Example: GeeksforGeeks is a Edtech company which uses services like Amazon

WorkSpaces or Google Cloud (GCP) Virtual Desktops to give its team members
access to the same coding setup with all the tools they required for the easy access of
this team work. Now their team members can easily log in from any device like a
laptop, tablet, or even a phone and use a virtual desktop that will run perfectly in the
cloud. This makes it easy for GeeksforGeeks company to manage, update, and keep
everything secure without requirement of physical computers for everyone.

4. Storage Virtualization: This combines storage from different servers into a single
system, making it easier to manage. It ensures smooth performance and efficient
operations even when the underlying hardware changes or fails.

Example: Amazon S3 is an example of storage virtualization because in S3 we can

easily store any amount of data from anywhere. Suppose a MNC have lots of files and
data of company to store. By Amazon S3 company can store all their files and data in
one place and access these from anywhere without any kind of issue in secure way.

5. Server Virtualization: This splits a physical server into multiple virtual servers,
each functioning independently. It helps improve performance, cut costs and makes
tasks like server migration and energy management easier.

Example: A startup company has a powerful physical server. This company can use
server virtualization software like VMware vSphere, Microsoft Hyper-V or KVM to create
more virtual machines(VMs) on that one server.

Each VM here is an isolated server, that runs on their own operating system( like
Windows and Linux) and run it's own applications. For example, a company might run
A web server on one VM, A database server on another VM, A file server on a third VM
all on the same physical machine. This reduces costs, makes it easier to manage and
back up servers, and allows quick recovery if one VM fails.

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6. Data Virtualization: This brings data from different sources together in one place
without needing to know where or how it’s stored. It creates a unified view of the data,
which can be accessed remotely via cloud services.

Example: Companies like Oracle and IBM offer solutions for this.

7. Hardware Virtualization – Explained Simply

Hardware Virtualization is a technology that allows you to create virtual versions

of physical computers (called virtual machines or VMs) using a software called a
hypervisor.

Definition:

Hardware virtualization is the process of using virtual machines to run multiple

operating systems on a single physical machine, where the hardware
resources (CPU, RAM, storage, etc.) are abstracted and shared.

Virtualization V/s Cloud Computing

Below is the table that shows the comparison between virtualization and Cloud
Computing:

Aspect Virtualization Cloud Computing

What it Creating multiple virtual Accessing computing resources (like

is versions of a physical resource storage, servers) via the internet

Where it On physical machines or On remote servers provided by cloud

runs servers service providers

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Aspect Virtualization Cloud Computing

Efficient use of physical On-demand access to resources over

Focus
resources the internet

Running multiple virtual

Storing data on Google Drive or
Example machines on a single physical
renting a virtual machine on AWS
server

Cloud providers manage the physical

You have more control over the
Control hardware; you manage only what you
virtual environment
use

🛠️Tools and Products Available for Virtualization

🔹 1. Server Virtualization Tools

Used to create and manage virtual servers.

 VMware vSphere / ESXi – Industry-leading virtualization platform.

 Microsoft Hyper-V – Built into Windows Server; good for Windows

environments.

 KVM (Kernel-based Virtual Machine) – Open-source; used in Linux.

 Citrix Hypervisor (formerly XenServer) – Open-source and enterprise-ready.

🔹 2. Desktop Virtualization Tools

Used for creating virtual desktops accessible remotely.

 VMware Horizon View – Manages VDI environments.

 Citrix Virtual Apps and Desktops – Leader in desktop virtualization.

 Microsoft Windows Virtual Desktop (WVD) – Cloud-based virtual desktop on

Azure.

 Parallels Desktop – For running Windows on Mac.

🔹 3. Application Virtualization Tools

Used to run apps in isolated environments without full installation.

 Microsoft App-V – Runs apps virtually without installing them on the host.

 VMware ThinApp – Package and run applications in isolated containers.

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  Turbo.net – Cloud-based app delivery and virtualization.

🔹 4. Storage Virtualization Tools

Combine physical storage devices into a single virtual storage system.

 VMware vSAN (Virtual SAN) – Integrates with vSphere to manage storage.

 Dell EMC VPLEX – For data availability across locations.

 NetApp ONTAP – Unified storage virtualization.

 HPE 3PAR StoreServ – Scalable and efficient storage.

🔹 5. Memory Virtualization Tools

Used to manage memory as a pooled, shareable resource.

 VMware vSphere Memory Ballooning – Allows memory sharing between

VMs.

 Oracle VM Server – Memory management in enterprise servers.

 Citrix Memory Optimization – Within desktop and app virtualization.

💡 Other General Virtualization Tools:

 VirtualBox (by Oracle) – Free and open-source virtualization tool.

 Proxmox VE – Open-source server virtualization platform.

 QEMU – Quick Emulator for both user-level and system-level virtualization.

Virtualization Environment Techniques

These are the methods or approaches used to virtualize hardware and software
resources in a cloud environment.

1. Full Virtualization

 What it is: Simulates complete hardware, so the guest OS runs unmodified.

 Used in: Most traditional virtualization platforms.

 Example: VMware, VirtualBox.

 ✅ Advantage: High compatibility.

 ❌ Drawback: Slightly more overhead.

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2. Paravirtualization

 What it is: Guest OS is modified to work with the virtualization layer.

 Used in: Systems where performance is more important than OS isolation.

 Example: Xen hypervisor.

 ✅ Advantage: Better performance.

 ❌ Drawback: Requires OS modification.

3. OS-Level Virtualization (Containerization)

 What it is: Multiple containers (isolated user spaces) share the same OS kernel.

 Used in: Lightweight and fast deployments.

 Example: Docker, LXC (Linux Containers).

 ✅ Advantage: Very efficient.

 ❌ Drawback: Less isolation than full VMs.

4. Hardware-Assisted Virtualization

 What it is: Uses CPU features like Intel VT-x or AMD-V to enhance
virtualization.

 Used in: Enhancing performance of full virtualization.

 Example: Modern Intel and AMD processors.

 ✅ Advantage: Reduces overhead.

 ❌ Drawback: Requires supported hardware.

5. Application Virtualization

 What it is: Allows running applications in a virtual environment without

installing them traditionally.

 Used in: Running legacy apps or for secure app delivery.

 Example: VMware ThinApp, Microsoft App-V.

 ✅ Advantage: Easy deployment.

 ❌ Drawback: Limited OS compatibility.