Virtualization on Linux

1. Introduction

Virtualization allows multiple operating systems to run on a single physical machine. This is essential for efficient resource utilization, testing, and development.

2. Key Concepts

• Hypervisor: The software that creates and manages virtual machines.
• Virtual Machine (VM): A software emulation of a physical computer.
• Guest OS: The operating system running inside a VM.
• Host OS: The operating system running directly on the physical hardware.

3. Types of Virtualization

1. Full Virtualization
2. Paravirtualization
3. OS-Level Virtualization (e.g., containers)

4. Setting Up KVM

KVM (Kernel-based Virtual Machine) is a popular virtualization technology on Linux. Below are the steps to set it up:

# Update the package list
sudo apt update

# Install KVM and related packages
sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils

# Verify installation
sudo systemctl status libvirtd
        

4.1 Creating a Virtual Machine

You can create a virtual machine using the `virt-install` command:

virt-install --name myvm --ram 2048 --disk path=/var/lib/libvirt/images/myvm.img,size=10 \
--vcpus 2 --os-type linux --os-variant ubuntu20.04 --network network=default \
--graphics none --console pty,target_type=serial --location 'http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/' \
--extra-args 'console=ttyS0,115200n8 serial'
        

5. Best Practices

• Regularly update your virtualization software.
• Monitor resource usage to avoid bottlenecks.
• Use snapshots to save VM states before making changes.
• Secure your host and guest OS with firewalls and updates.

6. FAQ