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Introduction to Virtualization

Virtualization is the process of creating a software-based (or virtual) representation of something rather than a physical one. In the context of Linux and servers, it usually refers to creating virtual machines (VMs) or containers.

How it Works​

A piece of software called a Hypervisor sits between the physical hardware (Host) and the virtual systems (Guests). The hypervisor allocates physical resources (CPU cores, RAM, disk space) to each guest, isolating them from one another.

Types of Hypervisors​

  1. Type 1 (Bare Metal): The hypervisor runs directly on the host's hardware to control the hardware and manage guest OSs. (e.g., Proxmox, VMware ESXi, KVM). High performance, used in data centers.
  2. Type 2 (Hosted): The hypervisor runs as an application on top of a conventional operating system. (e.g., VirtualBox, VMware Workstation). Easier to set up, usually used for desktop development.

Why Use Virtualization?​

  • Resource Efficiency: Run multiple servers on a single powerful physical machine, reducing hardware and electricity costs.
  • Isolation: A crash or security breach in one VM does not affect the others.
  • Snapshots and Backups: You can easily save the exact state of a VM and roll back if an update breaks the system.
  • Portability: VMs can often be moved between different physical hosts with minimal downtime.