How To Install KVM on AlmaLinux 9

Virtualization has become an essential aspect of modern computing, allowing users to run multiple operating systems on a single physical machine. Kernel-based Virtual Machine (KVM) is a popular open-source virtualization solution that leverages the power of the Linux kernel to provide efficient and stable virtualization capabilities. AlmaLinux 9, a community-driven, free, and open-source operating system that is binary compatible with Red Hat Enterprise Linux (RHEL), serves as an excellent platform for deploying KVM. In this comprehensive guide, we will walk you through the step-by-step process of installing KVM on AlmaLinux 9, enabling you to create and manage virtual machines with ease.

Prerequisites

Before proceeding with the installation of KVM on AlmaLinux 9, ensure that your system meets the following requirements:

• AlmaLinux 9 installed on your system
• CPU with hardware virtualization support (Intel VT-x or AMD-V)
• At least 4GB of RAM
• Minimum of 20GB disk space
• Administrative access with root or sudo privileges
• Internet connection for downloading necessary packages

Step 1: Verify Hardware Virtualization Support

Hardware virtualization is a crucial requirement for running KVM. To check if your CPU supports virtualization, run the following command in the terminal:

grep -e 'vmx\|svm' /proc/cpuinfo

If the command returns output containing “vmx” (for Intel CPUs) or “svm” (for AMD CPUs), your system supports hardware virtualization. If no output is returned, you may need to enable virtualization in your system’s BIOS settings. Consult your motherboard manual for specific instructions on enabling virtualization.

Step 2: Update AlmaLinux System

Before installing KVM, it’s essential to update your AlmaLinux system to ensure you have the latest packages and security patches. Run the following command to update your system:

sudo dnf update -y

Step 3: Install KVM and Supporting Packages

To install KVM and its supporting packages on AlmaLinux 9, execute the following command:

sudo dnf install qemu-kvm libvirt virt-install virt-manager -y

This command installs the necessary packages, including:

• qemu-kvm: The main KVM package that provides the virtualization capabilities.
• libvirt: A toolkit for managing virtualization platforms, including KVM.
• virt-install: A command-line tool for creating and installing virtual machines.
• virt-manager: A graphical user interface for managing virtual machines.

After the installation is complete, you can verify that the KVM modules are loaded by running:

lsmod | grep kvm

If the output shows the “kvm” and “kvm_intel” (or “kvm_amd”) modules, KVM is successfully installed and loaded.

Step 4: Start and Enable libvirtd Service

The libvirtd service is responsible for managing virtual machines. To start and enable the service, run the following commands:

sudo systemctl start libvirtd
sudo systemctl enable libvirtd

These commands start the libvirtd service and configure it to start automatically at system boot.

Step 5: Configure Networking for Virtual Machines

To enable network connectivity for your virtual machines, you need to set up a bridged network using NetworkManager. Follow these steps:

1. Create a bridge connection:

nmcli con add type bridge autoconnect yes con-name br0 ifname br0

2. Add your network interface to the bridge:

nmcli con add type bridge-slave autoconnect yes con-name br0-port1 ifname eth0 master br0

Replace “eth0” with the actual name of your network interface.

Step 6: Create a Virtual Machine

With KVM installed and the networking configured, you can now create a virtual machine. You can use either the command-line tool “virt-install” or the graphical interface “virt-manager” to create and manage virtual machines.

Here’s an example command to create a virtual machine using “virt-install“:

virt-install \
  --name=example-vm \
  --vcpus=2 \
  --memory=2048 \
  --cdrom=/path/to/install.iso \
  --disk size=20,format=qcow2 \
  --network bridge=br0 \
  --os-type=linux \
  --os-variant=almalinux9

This command creates a virtual machine named “example-vm” with 2 virtual CPUs, 2GB of RAM, a 20GB disk in the QCOW2 format, and connects it to the bridged network “br0”. Adjust the parameters according to your requirements.

Step 7: Managing Virtual Machines

Once you have created virtual machines, you can manage them using various tools. The “virsh” command-line tool and the “virt-manager” graphical interface provide convenient ways to control and monitor your virtual machines.

Here are some common “virsh” commands:

• List all virtual machines:

virsh list --all

• Start a virtual machine:

virsh start example-vm

• Shut down a virtual machine:

virsh shutdown example-vm

For a graphical interface, launch “virt-manager” from the command line or the application menu. It provides an intuitive way to create, configure, and manage virtual machines.

Troubleshooting Common Issues

If you encounter any issues during the installation or configuration of KVM on AlmaLinux 9, here are some troubleshooting tips:

• Virtualization not enabled: Ensure that hardware virtualization is enabled in your system’s BIOS settings.
• Network connectivity issues: Verify that the bridged network is correctly configured and the virtual machine is connected to the appropriate network.
• Insufficient resources: Make sure your system has enough RAM and disk space to accommodate the virtual machines.
• Permission problems: Ensure that you have the necessary permissions to manage virtual machines. Add your user to the “libvirt” group using the command: sudo usermod -aG libvirt <username>.

Congratulations! You have successfully installed KVM. Thanks for using this tutorial for installing the Kernel-based Virtual Machine (KVM) on your AlmaLinux 9 system. For additional or useful information, we recommend you check the official KVM website.