What is Virtualization in Cloud?

Cloud computing fundamentally changes how we acquire and utilize computing power.

This blog will introduce you to Virtualization concept that enable this transformation, focusing on how processing power is delivered and managed in the cloud.

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Virtualization: The Foundation of Cloud Compute

Virtualization is the cornerstone of cloud computing. It's the technology that allows cloud providers to deliver scalable, flexible, and cost-effective compute resources to millions of users.

Definition:

• Virtualization is the process of creating a software-based, or "virtual," version of something, rather than the actual physical version.
• In cloud computing, it primarily refers to creating virtual versions of computing resources like servers, storage devices, networks, and operating systems.
• This allows a single piece of physical hardware to run multiple isolated virtual environments simultaneously.

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Key Concepts:

• Host Machine: The physical computer hardware (server) that provides the resources.
• Guest Machine (Virtual Machine): The virtualized instance (e.g., a virtual server or operating system) that runs on the host machine.
• Hypervisor (Virtual Machine Monitor - VMM): A layer of software that sits between the physical hardware and the virtual machines. Its job is to create, run, and manage virtual machines, allocating the host machine's resources (CPU, memory, storage, network) to each guest machine and ensuring they operate independently.

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Types of Hypervisors:

Type 1 Hypervisor (Bare-Metal Hypervisor): Runs directly on the host computer's hardware, without an underlying operating system. It has direct access to the hardware, making it very efficient and secure.

• Example: VMware ESXi, Microsoft Hyper-V, Xen.
• Use Case: Cloud providers extensively use Type 1 hypervisors to run their massive data centers, as they offer high performance and resource isolation.

Type 2 Hypervisor (Hosted Hypervisor): Runs as a software application on top of an existing operating system.

• Example: VMware Workstation, Oracle VirtualBox.
• Use Case: Commonly used on personal computers for testing different operating systems or running specific applications in an isolated environment.

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How Virtualization Works (Simplified):

• Imagine you have a powerful physical server.
• Without virtualization, it can only run one operating system and its applications.
• With virtualization, the hypervisor acts as a traffic controller and resource manager. It carves up the physical server's CPU, RAM, and storage into smaller, isolated chunks.
• Each chunk then acts like a completely separate, independent computer, capable of running its own operating system and applications.
• From the perspective of the operating system inside the virtual machine, it believes it has dedicated hardware.

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Analogy: Dividing a Large House into Apartments Think of a large, single-family house.

Host Machine: The entire physical house itself.

Hypervisor:

• The landlord who manages the house, adds walls, and installs separate utility meters to create individual apartments.

Guest Machines (VMs):

• The individual apartments within the house. Each apartment has its own living space, kitchen, and bathroom, and operates independently.
• The tenants (applications) in one apartment don't directly affect those in another, even though they share the same physical building.

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Types of Virtualization:

1.Server Virtualization:

• Definition: The most common type, where a single physical server is divided into multiple virtual servers (VMs), each running its own operating system and applications.
• Analogy: One large pizza oven (physical server) being used to bake many different pizzas (virtual servers) simultaneously, each with its own settings and ingredients.

2.Application Virtualization:

• Definition: Separating an application from the underlying operating system it runs on. The application is streamed or accessed remotely, running in an isolated environment.
• Analogy: Using a streaming service for a video game. You play the game, but it's not actually installed on your local device; it's running remotely and streamed to you.

3.Desktop Virtualization:

• Definition: Separating a user's desktop environment from the physical hardware. Users can access their personalized desktop, applications, and data from any device.
• Analogy: Having a "personal office pod" that you can access from anywhere. All your files and software are in the pod, and you just connect to it from whatever device you have.

4.Network Virtualization:

• Definition: Abstracting network resources (like switches, routers, firewalls) into software-based virtual networks. This allows for the creation of logical network segments that are independent of the physical network hardware.
• Analogy: A single physical road (physical network) being divided into multiple, independent lanes (virtual networks) for different types of vehicles, each with its own traffic rules and speed limits, all managed by a central traffic control system.

5.Storage Virtualization:

• Definition: Pooling physical storage from multiple devices into a single, virtual storage resource. This virtual pool can then be allocated to various servers or applications as needed.
• Analogy: Combining multiple individual storage boxes (physical hard drives) into one giant, flexible storage locker (virtual storage pool) that you can divide and assign space from as needed, without worrying about which physical box the data is actually on.

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Benefits of Virtualization in Cloud Computing:

• Resource Utilization: Maximizes the use of physical hardware by running multiple virtual machines on a single server, reducing idle capacity.
• Isolation: Each virtual machine is isolated from others, preventing issues in one VM from affecting others on the same physical host.
• Flexibility: Easily provision, de-provision, and move virtual machines across different physical servers.
• Cost Efficiency: Reduces hardware costs, power consumption, and cooling requirements.
• Rapid Provisioning: Allows for the quick creation of new virtual machines, enabling rapid deployment of resources.

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Quick Note: The "Efficiency Enabler"

• Virtualization is the fundamental technology that makes cloud computing economically viable and technically feasible.
• It allows cloud providers to efficiently share their massive physical infrastructure among countless customers, delivering resources on demand and enabling the "pay-as-you-go" model we discussed earlier.