Cloud & Virtualization Week Part 1: The Magic of the Hypervisor

Virtualization is the process of using sogtware to create an abstraction layer over computer hardware. This will allow the hardware elements of a single computer processors, memory, storage, and more to be divided into multiple virtual computers, commonly called Virtual Machines (VMs).

1. Why Virtualize? (The “Business” Case Study)

Imagine your business needs a web server, a print server, and a file server.

• The Old Way: You buy three separate physical servers. If the print server only uses 5% of its power, 95% is wasted.
• The Virtual Way: You buy one “Beefy” server and run three VMs on it. You can move memory and CPU power between them as needed. It saves money, electricity, and space in your wiring closet.

2. Type 1 vs. Type 2 Hypervisors

A Hypervisor is the “Traffic Cop” software that manages the VMs and allocates hardware resources. On the Network+ exam, we probably should know the difference between the two types:

• Type 1: Bare Metal
  • The hypervisor is installed directly on the physical hardware. There is no middleman.
    • Examples: VMware ESXi, Microsoft Hyper-V, Proxmox.
  • Use Case: This is what you’ll find in your businesses data center. It is fast, efficient, and professional grade.
• Type 2: Hosted
  • The hypervisor runs as an Application on top of a normal operating system (like Windows or MacOS).
    • Examples: Oracle VirtualBox, VMware Workstations.
  • Use Case:
    • This is what you should use to study, you can run a Linux VM inside your Windows laptop/desktop to practice CLI commands without breaking your computer.

3. The Virtual Switch (vSwitch)

How do these “invisible” computers talk to each other? They use a Virtual Switch.

• Inside the physical server, the hypervisor creates a software-based switch.
• This allows you to create Virtual VLANs and route traffic between VMs without the data ever leaving the physical box. it’s incredible fast because it moves at the speed of system memory, not the speed of an Ethernet cable!

4. The “Support Associate” Reality: Snapshots

One of the greatest “Superpowers” of Virtualization is the Snapshot.

• The Scenario: You need to perform a major update on the payroll server.
• The Safety Net: You take a “Snapshot” (a point-in-time-copy) of the VM. If the update crashed the server, you don’t have to spend 10 hours rebuilding it. You just click “Revert,” and the server is back to exactly how it was 5 minutes ago.

🧪 The “Exam Tip” for Network+

As we know from how studies, CompTIA loves to ask about Resource Contention. This happens when you try to give your VMs more RAM or CPU than the physical server actually has. If your physical server has 32GB of RAM and you try to run four VMs with 10GB each, the whole system will crawl to a halt. Always keep an eye on your Hypervisor Dashboard!

What’s Next?

We’ve learned how to virtualize a single server. Tomorrow, we’re going bigger. We move into Cloud Service Models. We’ll talk about SaaS, PaaS, and Iaas and why you are already using “The Cloud” every time you open Google Workspace or Microsoft 365!