Day 3 - Virtual Machines

An Analogy for Virtual Machines

• Consider you have bought 2 acres of land and built a house on it

• You realized that your house and all other resources combined, takes up only 1 acre

• So, you built a house in the remaining 1 acre and rent it to a family

• This is an example of efficient usage of available resources, which is the core concept of Virtualization

Note

• Server is just a computer that hosts an application, so that the clients can access it through the internet

Before Virtualization

• Consider your team of developers created an application

• An application requires isolated environment and you need to serve multiple customers

• So, you deploy the copies of the application into 10 servers and each server has 50 GB RAM

• Later you realized that the application needs only 4 GB RAM, and the resources of the server are being under-utilized

Virtualization

• Virtualization is the process of creating virtual machines from a physical machine

• Virtual machine is actually a software based computer, that utilizes a logical partition of the resources from a physical machine

• Note that each Virtual Machine has it's own Operating System

• The logical partitioning, isolation of the environments, configuration of OS, etc is managed by a software called as Hypervisor

After Virtualization

• Now instead of using multiple servers that results mostly in under utilization, we can use Virtualization to use lesser number of servers and use available resources efficiently

• This concept of Virtualization eventually lead to Cloud Computing, which is one of the game changer in the Software Industry

Virtualization in Cloud

• The Cloud Service Providers buy a large set of powerful computers across the globe

• By virtualization, they provision the Virtual Machines with desired configuration in desired location, over the cloud

• This service is called Elastic Cloud Compute in AWS, Google Compute Engine in GCP Cloud