QEMU/KVM for absolute beginners

Introduction

This tutorial is designed for absolute beginners who want to learn about QEMU and KVM, two powerful tools for virtualization. We will explore the basics of hypervisors, specifically KVM, and provide step-by-step instructions on how to set them up using virt-manager. Understanding these tools is essential for efficiently managing virtual machines on your system.

Step 1: Understanding Hypervisors

• What is a Hypervisor?
  • A hypervisor is software that creates and runs virtual machines (VMs). It allows multiple operating systems to share a single hardware host.
• Types of Hypervisors:
  • Type 1: Runs directly on the hardware (bare-metal).
  • Type 2: Runs on top of an operating system.

Step 2: Installing KVM

• Check if your CPU supports virtualization:

  • Open a terminal and run:

    egrep -c '(vmx|svm)' /proc/cpuinfo
    

  • A result greater than zero indicates virtualization is supported.

• Install KVM and necessary packages:

  • For Fedora, run:

    sudo dnf install @virtualization
    

  • For Ubuntu, run:

    sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils
    

• Start and enable the libvirt service:

  • Run:

    sudo systemctl start libvirtd
    sudo systemctl enable libvirtd
    

Step 3: Installing Virt-Manager

• Install Virt-Manager:

  • For Fedora, run:

    sudo dnf install virt-manager
    

  • For Ubuntu, run:

    sudo apt install virt-manager
    

• Start Virt-Manager:

  • Open the application from your applications menu.

Step 4: Setting Up a Virtual Machine

• Create a new VM in Virt-Manager:

  • Click on the “Create a new virtual machine” button.

• Select the installation method:

  • Choose to install from ISO image, network installation, or other media.

• Choose the operating system:

  • Select the OS type and version you want to install.

• Allocate resources:

  • Specify RAM and CPU allocation for your VM.

• Set up storage:

  • Create or select a virtual hard disk for the VM.

• Finalize and install:

  • Review the settings and click “Finish” to start the installation.

Step 5: Managing Your Virtual Machine

• Starting and Stopping VMs:

  • Use the controls in Virt-Manager to start or shut down your VMs as needed.

• Accessing the VM:

  • Connect to your VM's console through Virt-Manager to interact with it.

Conclusion

In this tutorial, we have covered the basics of hypervisors, installed KVM and virt-manager, and set up your first virtual machine. You can now explore the capabilities of virtualization on your system. For further learning, consider experimenting with different operating systems and configurations within your VMs. Happy virtualizing!