How To Install KVM on Ubuntu 24.04 LTS

Kernel-based Virtual Machine (KVM) has become an integral part of modern computing infrastructure, offering powerful virtualization capabilities to users and organizations alike. As businesses and individuals increasingly rely on virtual environments for development, testing, and production workloads, understanding how to install and configure KVM on Ubuntu 24.04 LTS is more crucial than ever.

Ubuntu 24.04 LTS, the latest long-term support release, provides an excellent platform for KVM deployment. This article will guide you through the process of installing KVM on Ubuntu 24.04 LTS, exploring its features, and optimizing its performance for your specific needs.

Prerequisites

Before diving into the installation process, it’s essential to ensure your system meets the necessary requirements:

• A 64-bit processor with hardware virtualization support (Intel VT-x or AMD-V)
• At least 4GB of RAM (8GB or more recommended for running multiple VMs)
• Sufficient storage space for virtual machine images
• Ubuntu 24.04 LTS installed and updated

To check if your processor supports hardware virtualization, run the following command in the terminal:

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

If the output is greater than 0, your system supports hardware virtualization. Next, update your Ubuntu system:

sudo apt update && sudo apt upgrade -y

Understanding KVM

KVM, or Kernel-based Virtual Machine, is an open-source virtualization technology built into the Linux kernel. It allows you to create and run multiple virtual machines (VMs) on a single physical host, each with its own virtualized hardware resources.

Key benefits of using KVM include:

• Near-native performance for guest operating systems
• Efficient resource utilization
• Seamless integration with Linux systems
• Active community support and continuous development

Compared to other virtualization solutions like VirtualBox or VMware, KVM offers better performance and tighter integration with the Linux ecosystem. It’s particularly well-suited for server virtualization and cloud computing environments.

Preparing Your System

Before installing KVM, you need to prepare your system by enabling virtualization support in the BIOS/UEFI and installing necessary packages.

Enabling Virtualization in BIOS/UEFI

1. Restart your computer and enter the BIOS/UEFI setup (usually by pressing F2, F12, or Del during boot)
2. Look for options related to virtualization, such as “Intel Virtualization Technology” or “AMD-V”
3. Enable these options
4. Save changes and exit the BIOS/UEFI setup

Installing Necessary Packages

Open a terminal and run the following command to install KVM and related tools:

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

Configuring User Permissions

To allow your user account to manage virtual machines, add yourself to the libvirt and kvm groups:

sudo usermod -aG libvirt $USER
sudo usermod -aG kvm $USER

Log out and log back in for the changes to take effect.

Installing KVM on Ubuntu 24.04 LTS

Now that your system is prepared, let’s proceed with the KVM installation:

Step-by-Step Installation Process

1. Verify KVM installation:

   kvm-ok

   If you see “KVM acceleration can be used”, you’re good to go.

2. Start and enable the libvirtd service:

   sudo systemctl start libvirtd
   sudo systemctl enable libvirtd

3. Verify the installation:

   virsh list --all

   This should display an empty list of virtual machines.

Common Installation Issues and Solutions

If you encounter any issues during installation, try these troubleshooting steps:

• Ensure virtualization is enabled in BIOS/UEFI
• Check for conflicting virtualization software (e.g., VirtualBox)
• Verify that all required packages are installed correctly
• Consult the system logs for error messages: sudo journalctl -xe

Configuring KVM

After successful installation, it’s time to configure KVM for optimal performance and usability.

Setting up Networking

KVM offers several networking modes. The default NAT mode works well for most use cases, but you can also set up bridged networking for more advanced configurations:

sudo virsh net-list --all
sudo virsh net-start default
sudo virsh net-autostart default

Creating Storage Pools

Storage pools help manage VM disk images efficiently. Create a new storage pool:

sudo virsh pool-define-as --name vmpool --type dir --target /var/lib/libvirt/images
sudo virsh pool-build vmpool
sudo virsh pool-start vmpool
sudo virsh pool-autostart vmpool

Optimizing KVM Performance

To enhance KVM performance:

• Use virtio drivers for disk and network devices
• Allocate sufficient RAM and CPU cores to VMs
• Enable CPU passthrough for compute-intensive workloads
• Use SSD storage for VM images when possible

Creating and Managing Virtual Machines

With KVM configured, you can now create and manage virtual machines.

Using virt-manager GUI

Virt-manager provides a user-friendly interface for VM management:

1. Launch virt-manager: virt-manager
2. Click “Create a new virtual machine”
3. Follow the wizard to set up your VM, specifying OS type, resources, and storage

Command-line VM Creation with virsh

For advanced users, virsh offers powerful command-line VM management:

sudo virt-install --name ubuntu-vm --ram 2048 --disk path=/var/lib/libvirt/images/ubuntu-vm.qcow2,size=20 --vcpus 2 --os-type linux --os-variant ubuntu20.04 --network bridge=virbr0 --graphics none --console pty,target_type=serial --location 'http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/' --extra-args 'console=ttyS0,115200n8 serial'

Importing Existing VMs

To import an existing VM:

sudo virt-convert -i vmdk source_vm.vmdk -o qcow2 destination_vm.qcow2
sudo virt-install --name imported-vm --ram 2048 --vcpus 2 --disk path=destination_vm.qcow2 --import --os-variant ubuntu20.04

Advanced KVM Features

KVM offers several advanced features for enterprise-grade virtualization:

Live Migration

Live migration allows you to move running VMs between hosts with minimal downtime:

sudo virsh migrate --live vm-name qemu+ssh://destination-host/system

Snapshots and Backups

Create VM snapshots for easy rollback:

sudo virsh snapshot-create-as --domain vm-name --name snapshot1 --description "First snapshot"

PCI Passthrough

PCI passthrough enables VMs to directly access physical hardware for improved performance. This is particularly useful for GPU-intensive workloads:

sudo vfio-pci-override-vga.sh
sudo virsh attach-device vm-name pci-passthrough.xml

Troubleshooting Common KVM Issues

Even with careful setup, you may encounter issues. Here are some common problems and their solutions:

Performance Problems

• Ensure VMs are not overcommitting host resources
• Use virtio drivers for improved I/O performance
• Monitor host and guest performance with tools like top, htop, or virt-top

Networking Issues

• Verify network configuration in both host and guest
• Check firewall rules that might be blocking traffic
• Ensure bridge interfaces are correctly configured

Storage-related Challenges

• Monitor disk usage and expand VM disks as needed
• Use thin provisioning to optimize storage utilization
• Regularly defragment and optimize VM disk images

Congratulations! You have successfully installed KVM. Thanks for using this tutorial for installing the KVM virtualization on Ubuntu 24.04 LTS system. For additional help or useful information, we recommend you check the official KVM website.