QEMU is a fast processor emulator that works in conjunction with KVM (Kernel-based Virtual Machine) to provide a full-fledged virtualization solution for Linux. Virt-manager, also known as Virtual Machine Manager, is a desktop application for managing virtual machines through libvirt. This article will guide you through the steps of setting up QEMU/KVM with virt-manager on the CentOS 7 operating system, allowing you to conveniently manage virtual machines using a graphical user interface.

Prerequisites

• Clean installation of CentOS 7.
• User account with sudo privileges.

Step 1: Installing Required Packages

The first step is to install the QEMU, KVM, and virt-manager packages. Open a terminal and enter the following commands:

sudo yum update -y
sudo yum install qemu-kvm libvirt libvirt-python libguestfs-tools virt-install
sudo yum install virt-manager -y

Step 2: Starting and Configuring Services

After installing the packages, ensure that the libvirtd (libvirt daemon) and kvm services are started and configured to start automatically on system boot:

sudo systemctl start libvirtd
sudo systemctl enable libvirtd

Step 3: Verifying Installation

To verify that KVM is correctly installed and your hardware supports virtualization, run:

lsmod | grep kvm

If you see outputs such as kvm_intel or kvm_amd, it means that KVM is properly installed and functioning.

Step 4: Creating a Virtual Machine Using virt-manager

Now that QEMU/KVM and virt-manager are installed and correctly configured, you can start creating virtual machines:

1. Launch virt-manager from the terminal or your desktop environment's menu:

   virt-manager
   

2. Upon launching, the virt-manager graphical interface will appear. Click on the "Create a new virtual machine" icon.

3. Follow the wizard to create a new virtual machine. You can choose a local installation media (e.g., ISO file of the operating system) or use network installation.

4. Configure the parameters of the virtual machine, such as RAM amount and disk size.

5. Once configuration is complete, click "Finish". The virtual machine will now begin installation.

Step 5: Managing and Using Virtual Machines

Using virt-manager, you can easily manage the virtual machines you've created. It provides an interface for starting, stopping, and connecting to virtual machines, as well as accessing their consoles and modifying their configurations.

 

Configuring QEMU/KVM with virt-manager on CentOS 7 provides you with a powerful and flexible platform for virtualization. With the graphical interface of virt-manager, managing virtual machines becomes easy and intuitive. For more information or detailed configuration options, we recommend consulting the documentation of the QEMU, KVM, and libvirt projects.