Virtualization stands as a pivotal technology in the realm of IT, allowing multiple virtual machines to run on a single physical hardware. KVM (Kernel-based Virtual Machine) serves as an open-source virtualization solution for Linux on x86 architecture, supporting processor-level virtualization. CentOS 7, the community edition of Red Hat Enterprise Linux, provides a robust platform for deploying KVM. This article will walk you through the step-by-step process of configuring KVM on CentOS 7.
Prerequisites
Before initiating the installation, ensure that your system meets the following requirements:
- Minimum of 2GB RAM (recommended more for better virtual machine performance)
- CPU with virtualization support (Intel VT-x or AMD-V)
- Clean installation of CentOS 7
Step 1: Installing Required Software
The first step involves installing the necessary software for running KVM. Open a terminal and execute the following commands:
sudo yum update
sudo yum install qemu-kvm libvirt libvirt-python libguestfs-tools virt-install
This command updates your system base and installs KVM along with tools for managing virtual machines.
Step 2: Starting and Configuring Services
Post-installation, it's essential to start and enable the libvirtd service responsible for virtualization management.
sudo systemctl start libvirtd
sudo systemctl enable libvirtd
Step 3: Verifying Installation
To verify that KVM is correctly installed and running, you can use the lsmod | grep kvm command. If everything is set up correctly, you should see output similar to the following:
kvm_intel 162153 0
kvm 525409 1 kvm_intel
Step 4: Creating a Virtual Machine
Now that you have KVM properly set up, you can create your first virtual machine. Use virt-install to create a virtual machine with the following command:
sudo virt-install --name=exampleVM --ram=2048 --vcpus=2 --disk path=/var/lib/libvirt/images/exampleVM.img,size=10 --graphics none --location='http://mirror.centos.org/centos/7/os/x86_64/' --extra-args 'console=ttyS0'
This command will create a virtual machine named exampleVM with 2GB RAM, 2 virtual CPUs, and a 10GB disk space.
Step 5: Managing and Monitoring Virtual Machines
For managing virtual machines, you can use the virsh tool. For example, to get a list of all running virtual machines:
sudo virsh list --all
To monitor the performance of virtual machines, you can use tools like virt-top.
You now have a basic understanding of how to set up and manage virtual machines using KVM on CentOS 7. Virtualization with KVM offers a flexible and efficient solution for creating and managing virtual machines, ideal for development, testing, or production deployment.
