What you need to know:
KVM (Kernel-based Virtual Machine) is a virtualization technology that is free, open-source, and available in most modern Linux distributions. Thanks to it, you can create and run Linux and Windows-based virtual machines that are independent of one another and each comes with virtualized hardware like network cards, graphic cards, disk storage, and more. All that’s needed is a Linux distribution that supports KVM and a CPU that has virtualization extensions (Intel VT or AMD-V). The downside of using KVM is that it’s not available in Windows as it is bundled with the Linux kernel. Also, its centralized hardware approach may result in downtime for the virtual machines in case the host computer experiences a malfunction.
Virtual machines (VMs) allow you to run virtualized computers as regular programs within your physical computer. There are different software solutions for creating and running VMs. In this guide, we’ll focus on KVM and explore its capabilities.
Table of Contents:
What Is KVM?
KVM, which stands for Kernel-based Virtual Machine, is a full-featured virtualization software that has been part of the Linux kernel since early 2007. Thanks to KVM, you can create, manage, and run virtual machines that are based on Linux and Windows. All that you need is a host computer running Linux with KVM and a CPU that supports virtualization (Intel VT or AMD-V).
What Is a Virtual Machine?
A Virtual Machine (VM) is a sophisticated computer process that emulates the operation of an entire physical computer. In other words, a VM has its own virtualized components like a graphics card, a network card, a sound card, storage, etc, and runs an operating system like Windows and Linux. A single physical computer can run multiple VMs at a time and you can interact with those VMs in the same way you would interact with a regular computer. You can learn more by reading our article on virtual machines.
KVM Advantages
There are many reasons to choose KVM over other virtualization solutions. Below, we’ll outline the most notable ones:
- KVM is free, open-source, and ships with most modern Linux distributions.
- KVM offers live migrations. In other words, a virtual machine can be moved from one physical computer to another without having to shut it down.
- KVM provides a single hardware platform for all guest systems. This ensures that no driver conflicts will occur.
- KVM supports snapshots for its VMs.
- KVM is 15 years old. This means that it is an established technology that has no major bugs or issues.
- The resources for each VM can be scaled in real-time, enabling complete flexibility.
- KVM supports automated administration through libvirt.
KVM Disadvantages
KVM also has a few notable drawbacks:
- Since KVM is bundled with the Linux kernel, you need to have a Linux distribution as your host OS.
- KVM’s hardware strategy is to have a single physical computer power one or more virtual machines. The downside here is that if the physical computer experiences a malfunction, all of its VMs will go down.
Use Cases
Since KVM comes bundled with Linux, the virtualization technology is popular in places where Linux is used. Two such cases are software development and web hosting.
Software developers often use KVM to test their products in different environments. Hosting companies, on the other hand, can leverage KVM to create comprehensive server systems.
Here at ZETTAHOST.com, we use KVM as the backbone for the various Virtual Private Server packages that we offer. So, whenever you purchase a VPS plan from us, it will be powered and managed by KVM.
Conclusion
Using KVM, or virtualization technology in general, is a great way to fully utilize the processing power of your computer while also neatly separating every type of service in its own environment. This affords you the stability you would get if every service was run by an independent computer but without the extra hardware and financial investment.