Creating Virtual Machines on Linux with Virt-Manager

Virtualization is a handy way to run multiple operating systems on a single machine—ideal for testing, development, or creating isolated environments. On Linux, Virt-Manager offers a simple and powerful graphical interface to manage virtual machines using KVM.

This post walks you through the steps to install and use Virt-Manager. I’ve demonstrated using Debian, but the process is similar across most Linux distributions—just replace the package manager commands accordingly.

Why Choose Virt-Manager over VirtualBox or Other Hypervisors?

Virt-Manager leverages KVM, which is built into the Linux kernel, providing near-native performance and better integration with Linux systems compared to VirtualBox. It’s fully open source with no extra kernel modules needed, reducing maintenance. Virt-Manager supports advanced features like snapshots, cloning, and flexible networking, all while being lightweight and suitable for both desktop and server environments. Its ability to manage VMs locally or remotely makes it ideal for professional Linux users seeking efficiency and control.

Install Required Packages

On Debian-based systems (like Ubuntu), use:

sudo apt -y install virt-manager libvirt-daemon-system libvirt-clients bridge-utils

For other distributions:

Fedora/RHEL:

sudo dnf install virt-manager libvirt bridge-utils

Arch/Manjaro:

sudo pacman -S virt-manager qemu vde2 bridge-utils openbsd-netcat

Add Your User to Groups

Add your user to the libvirt and kvm groups to manage VMs without superuser permissions:

sudo usermod -aG libvirt $(whoami) && sudo usermod -aG kvm $(whoami)

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

Launch Virt-Manager

Start Virt-Manager from your applications menu or run:

virt-manager

Prepare the ISO Image

To install a guest operating system, copy your ISO file to the default image directory:

sudo cp ~/Downloads/debian.iso /var/lib/libvirt/images/

Replace debian.iso with the appropriate ISO file you plan to use.

Create a New Virtual Machine

Use the Virt-Manager interface to set up a new VM:

• Open Virt-Manager.
• Click "Create a new virtual machine."
• Select "Local install media (ISO image or CDROM)" and click Forward.
• Browse and select the ISO file, then choose the correct operating system type.
• Allocate memory and CPU resources.
• Create or select a virtual hard disk.
• Give your virtual machine a name and click Finish.

The VM will boot from the ISO, and you can proceed with installing the OS as usual.