Kernel-based Virtual Machine (KVM) has become the cornerstone of virtualization in the Linux ecosystem, offering a robust, performance-driven environment for managing virtual machines (VMs). CentOS and Red Hat Enterprise Linux (RHEL) stand out as popular distributions for deploying KVM, thanks to their stability and extensive support. This article delves into the nuances of setting up KVM on these platforms, catering to both novices and seasoned users seeking to harness the power of virtualization.

Understanding KVM

KVM turns your Linux server into a hypervisor, allowing you to run multiple, isolated VMs. Each VM operates with its own private virtualized hardware, such as CPU, memory, and storage, making it an ideal choice for developing, testing, or deploying applications in isolated environments.

Preparing Your System

Before diving into KVM installation, ensure your CentOS/RHEL system is up-to-date. Open your terminal and execute:

sudo yum update

Check if your CPU supports hardware virtualization:

egrep -c '(vmx|svm)' /proc/cpuinfo

A non-zero output indicates readiness for KVM installation.

Installing KVM and Tools

KVM installation on CentOS and RHEL is straightforward, thanks to the yum package manager. Install KVM and additional tools for managing VMs with the following command:

sudo yum install qemu-kvm libvirt libvirt-python libguestfs-tools virt-install

This command installs the core KVM packages, the libvirt library for managing KVM through a user-friendly API, and tools for VM creation and management.

Starting and Enabling libvirtd

The libvirtd daemon is essential for managing virtual machines. Start and enable it on boot using:

sudo systemctl start libvirtd
sudo systemctl enable libvirtd

Configuring SELinux for KVM

SELinux, a mandatory access control (MAC) system on CentOS/RHEL, enhances security by restricting VMs’ access to the host system. Ensure SELinux is in enforcing mode and properly configured for KVM. The default SELinux policy in CentOS/RHEL typically supports KVM out of the box, but it’s wise to confirm:

getenforce

If it’s not in enforcing mode, enable it by editing /etc/selinux/config and setting SELINUX=enforcing, then reboot.

Integrating KVM with Cockpit for Web-based Management

Cockpit, a web-based interface, simplifies KVM management, offering a graphical overview of VMs, their performance, and system resources. Install Cockpit on CentOS/RHEL:

sudo yum install cockpit cockpit-machines

Enable and start Cockpit:

sudo systemctl enable --now cockpit.socket

Access Cockpit through your web browser by navigating to https://<your-server-ip>:9090 and log in with your system credentials.

Creating Your First VM

With KVM and tools installed, create your first VM. Here’s a simple example using virt-install:

sudo virt-install \
--name=myvm \
--ram=1024 \
--vcpus=1 \
--cdrom=/path/to/iso/image \
--disk size=10,path=/var/lib/libvirt/images/myvm.img \
--network bridge=virbr0 \
--graphics vnc

This command creates a VM named “myvm” with 1 GB of RAM, one CPU, a 10 GB disk, and network access through a bridged connection.

Leveraging Shape.host Cloud VPS Services

For those seeking a managed solution, Shape.host offers Cloud VPS services, providing scalable, high-performance virtual private servers without the complexity of manual setup. Shape.host’s Cloud VPS services are ideal for users looking for a ready-to-use, secure, and flexible hosting environment, complemented by 24/7 support.

Wrapping Up

Setting up KVM on CentOS/RHEL is a powerful way to leverage virtualization, whether you’re developing applications, testing environments, or managing a virtualized server infrastructure. With the steps outlined in this guide, users can confidently deploy KVM, taking advantage of CentOS/RHEL’s robustness and Shape.host’s managed Cloud VPS solutions for an optimized virtualization experience.