Install VirtManager for KVM on Arch Linux

VirtManager (Virtual Machine Manager) is a graphical interface used to manage virtual machines via KVM (Kernel-based Virtual Machine) on Linux. It's widely used because of its simplicity and user-friendly interface for creating, managing, and configuring virtual machines. If you’re using Arch Linux, the installation process is straightforward. This guide will walk you through the steps to install and set up VirtManager for KVM on Arch Linux.

Step 1: Install Required Packages

If you haven't already installed KVM, Libvirt, and the required tools, use the following command to install them:

sudo pacman -S qemu libvirt virt-manager bridge-utils libguestfs nano

This will install KVM, Libvirt, VirtManager, libguestfs, and Nano (for editing configuration files).

Step 2: Edit the libvirtd Configuration

1. Find and modify the following settings:This ensures that only the libvirt group has read and write access to the UNIX domain socket used by Libvirt.
2. Set the UNIX socket permissions for the R/W socket:Around line 102, change the unix_sock_rw_perms line to:

unix_sock_rw_perms = "0770"

3. Set the UNIX domain socket group ownership to libvirt:Around line 85, change the unix_sock_group line to:

unix_sock_group = "libvirt"

4. Open the libvirtd.conf file for editing using Nano (or any text editor you prefer):

sudo nano /etc/libvirt/libvirtd.conf

Step 3: Add Your User to the libvirt Group

To allow your standard user to manage virtual machines, you need to add your user to the libvirt group. Run the following command:

sudo usermod -a -G libvirt $(whoami)

This adds your current user to the libvirt group, giving you the necessary permissions.

Step 4: Apply Group Changes

To apply the group changes immediately without logging out and back in, use the newgrp command:

newgrp libvirt

This ensures that your user is immediately recognized as part of the libvirt group for the current session.

sudo systemctl enable --now libvirtd.service

Step 5: Restart the libvirt Daemon

For the changes to take effect, you need to restart the libvirt daemon:

sudo systemctl restart libvirtd.service

This reloads the libvirtd service with the updated configuration.

If errors occurs, it is recommended to restart the computer.

Step 6: Verify the Setup

After making these changes, you should be able to use your normal user account to manage KVM and virtual machines without needing sudo. You can verify by running VirtManager or using virsh commands.

For example, try running the following command to list all VMs (even if they aren't running):

virsh list --all

You should be able to see the list of virtual machines without requiring sudo.

Conclusion

With these steps, you've configured your system to allow a standard Linux user account to manage KVM through Libvirt. By adjusting the permissions on the UNIX domain socket and adding your user to the libvirt group, you’ve enabled secure access to virtualization tools such as VirtManager and virsh.