🎥 Video Reference:

🚀 Overview

In today’s session, I started understanding Virtual Machines (VMs) — a core concept in cloud and DevOps. I learned how VMs maximize hardware efficiency, and how cloud providers offer VMs as services. Here's a breakdown of what I learned:

🧠 Key Learnings from the Video

1. What is a Server?

A server is just a powerful computer that serves applications or services to clients. When we talk about servers in the cloud or on-premises, we’re referring to physical machines with resources like CPU, RAM, disk, etc.

2. What is a Virtual Machine (VM)?

A VM is a virtualized version of a server that shares physical hardware. It’s an isolated, software-defined machine created and managed by a hypervisor.

Example from the video:

Think of having one house on a plot of land (physical server). If only 20% of the land is being used, why not build more houses (VMs) on the same land? That’s the idea behind virtualization.

3. What is a Hypervisor?

A hypervisor is the software that allows virtualization. It creates and manages VMs by allocating CPU, RAM, and storage from the host machine.

Two types:

Type 1 (Bare-metal): Installed directly on hardware (e.g., VMware ESXi, Hyper-V)
Type 2 (Hosted): Runs on top of a base OS (e.g., VirtualBox, VMware Workstation)

4. Why Do We Use VMs?

Reduce hardware wastage.
Multiple VMs can run different OSs on the same physical machine.
Each VM is isolated, meaning failure or crash of one VM won’t affect others.
VMs are cost-effective, scalable, and easier to manage.

🛠️ Cloud + VM Integration (From the Video)

I also learned how cloud providers like AWS, Azure, and Google Cloud provide VMs.

Steps explained:

I request a VM with 8GB RAM, 12 cores, in a region like Mumbai.
Cloud checks physical servers for resource availability.
Hypervisor creates a VM on a suitable host.
I receive login credentials and can access the VM remotely via SSH/RDP.
I only pay for what I use — this is how cloud platforms scale efficiently.

📈 Diagram (Based on Video Explanation)

pgsqlCopyEdit+--------------------------+
|     Physical Server      |
|  +--------------------+  |
|  |     Hypervisor     |  |
|  | +----+ +----+ +--+ |  |
|  | |VM1| |VM2| |VM3| |  |
|  | +----+ +----+ +--+ |  |
|  +--------------------+  |
+--------------------------+

Each VM has:

Independent OS (Windows, Linux)
Allocated resources (CPU, RAM)
Isolated file system and network

📝 My Reflections

This session gave me clarity on:

Why companies use VMs instead of many physical machines.
How virtualization improves cost, space, and resource usage.
The foundational role of VMs in DevOps, cloud computing, and CI/CD setups.

Before this, I only heard about EC2 instances on AWS. Now I understand the exact virtualization layer underneath them.

✅ Day 3 To-Do & Completed

Watched full video on Virtual Machines
Understood physical vs virtual server differences
Learned hypervisor types (Type 1 & 2)
Practiced diagramming VM architecture
Explored AWS EC2 dashboard to relate concepts

🔜 What’s Next?

In the next session (Day 4), I’ll learn:

How to create a VM practically (on VirtualBox, AWS)
Hands-on setup and resource allocation
Understanding VM lifecycle and snapshots

📘 Day 3 – Virtual Machines in DevOps | #30DaysOfDevOps