Virtualization is a technology that allows you to create multiple simulated environments or dedicated resources from a single, physical hardware system. This is particularly useful for testing, development, and efficient resource utilization. In this section, we will explore the basics of virtualization, the tools available in Linux, and how to set up and manage virtual machines (VMs).

• Definition: Virtualization is the process of creating a virtual version of something, such as hardware platforms, storage devices, and network resources.
• Types of Virtualization:
  • Full Virtualization: The VM simulates enough hardware to allow an unmodified guest OS to run in isolation.
  • Paravirtualization: The guest OS is modified to run on a virtual machine, which can improve performance.
  • Containerization: Lightweight virtualization where applications run in isolated user spaces, sharing the same OS kernel.

• Resource Efficiency: Better utilization of hardware resources.
• Isolation: Each VM is isolated from others, enhancing security and stability.
• Scalability: Easy to scale up or down based on demand.
• Flexibility: Run multiple OSes and applications on a single physical machine.

• Description: KVM is a full virtualization solution for Linux on x86 hardware containing virtualization extensions (Intel VT or AMD-V).
• Features:
  • Integrated into the Linux kernel.
  • Supports a wide range of guest OSes.
  • High performance and scalability.

• Description: QEMU is a generic and open-source machine emulator and virtualizer.
• Features:
  • Can emulate a full system (including peripherals).
  • Works with KVM to provide hardware-assisted virtualization.

• Description: A powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use.
• Features:
  • User-friendly interface.
  • Supports a wide range of guest OSes.
  • Cross-platform support.

• Description: A platform for developing, shipping, and running applications in containers.
• Features:
  • Lightweight and fast.
  • Simplifies application deployment.
  • Extensive ecosystem and community support.

• A Linux distribution with KVM support (e.g., Ubuntu, Fedora).
• Hardware with virtualization support (Intel VT-x or AMD-V).

1. Install KVM and related packages:

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

2. Verify KVM installation:

   sudo systemctl status libvirtd
   

3. Add your user to the libvirt group:

   sudo usermod -aG libvirt $(whoami)
   

4. Reboot your system to apply group changes.

5. Launch Virt-Manager:

   virt-manager
   

6. Create a new VM:

   • Open Virt-Manager.
   • Click on "Create a new virtual machine".
   • Follow the wizard to configure your VM (choose installation media, allocate memory and CPU, create a virtual disk, etc.).

1. Open Virt-Manager and click on "Create a new virtual machine".
2. Choose Installation Media:
   • Select "Local install media (ISO image or CDROM)".
   • Browse and select your ISO file.
3. Allocate Memory and CPU:
   • Assign the desired amount of RAM and CPU cores.
4. Create a Virtual Disk:
   • Choose "Create a disk image on the computer's hard drive".
   • Specify the size of the virtual disk.
5. Network Configuration:
   • Use the default network settings or customize as needed.
6. Finalize and Start the VM:
   • Review your settings and click "Finish" to create and start the VM.

1. Objective: Set up a virtual machine running Ubuntu 20.04 using KVM and Virt-Manager.
2. Steps:
   • Install KVM and related packages.
   • Verify the installation.
   • Add your user to the libvirt group.
   • Reboot your system.
   • Launch Virt-Manager and create a new VM with the Ubuntu 20.04 ISO.
3. Expected Outcome: A running Ubuntu 20.04 virtual machine.

1. Install KVM and related packages:

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

2. Verify KVM installation:

   sudo systemctl status libvirtd
   

3. Add your user to the libvirt group:

   sudo usermod -aG libvirt $(whoami)
   

4. Reboot your system.

5. Launch Virt-Manager:

   virt-manager
   

6. Create a new VM:

   • Open Virt-Manager.
   • Click on "Create a new virtual machine".
   • Select "Local install media (ISO image or CDROM)".
   • Browse and select the Ubuntu 20.04 ISO file.
   • Allocate 2048 MB of RAM and 2 CPU cores.
   • Create a 20 GB virtual disk.
   • Use the default network settings.
   • Click "Finish" to create and start the VM.

In this section, we covered the basics of virtualization, the benefits it offers, and the tools available in Linux for virtualization. We also walked through the steps to set up a virtual machine using KVM and Virt-Manager. By mastering these skills, you can efficiently manage multiple environments and optimize resource usage on your Linux system. In the next section, we will delve into Linux Containers and Docker, which offer a lightweight alternative to traditional virtualization.