QEMU, KVM, VirtualBox, and Hyper-V are virtualization technologies that allow you to run multiple operating systems on a single physical machine. While they all serve a similar purpose, there are some key differences between these technologies that are worth noting.

What Is KVM?

Kernel-based Virtual Machine (KVM) is an open-source virtualization solution built into the Linux kernel. It allows you to create and run virtual machines on a Linux host system using hardware acceleration, providing high performance and low overhead. KVM is often used in production environments due to its stability and reliability.

To use KVM, you must have a processor with hardware virtualization support and a compatible version of the Linux kernel. Once these prerequisites are met, you can create and run operating systems using the KVM software, which is typically included with most modern Linux distributions.

KVM is also commonly used as a backend for other virtualization software, such as QEMU. This allows other virtualization programs to leverage the benefits of KVM's hardware acceleration and integration with the Linux kernel.

What Is VirtualBox?

VirtualBox is a virtualization software developed by Oracle that allows you to run multiple operating systems on a single physical computer. It is a powerful tool using which you can create and run virtual machines, each with its own operating system, on your computer. This can be useful for various purposes, such as testing software, running multiple operating systems simultaneously, and more.

To use VirtualBox for virtualization, you need to install it on your computer and create a new virtual machine. You can then install an operating system on the virtual machine and use it just like you would on a physical computer.

You can configure the virtual machine's hardware settings, such as the amount of memory and CPU resources it has access to, to meet the needs of the operating system and applications you plan to run on it.

There's another contender when it comes to hypervisors: VMware. Check out the differences between VMware and VirtualBox to find out which one's best for you.

What Is QEMU?

QEMU official site

QEMU (Quick Emulator) is an open-source emulator and virtualization software that allows you to run virtual machines on various host platforms, including Linux, Windows, and macOS. It is often used for testing and development purposes, as it can simulate a wide range of hardware configurations and is highly customizable.

To use QEMU, you must have a host system with a compatible processor and operating system. Once these prerequisites are met, you can create and run virtual machines using the QEMU software, which you can typically install on your system from the QEMU website or through the default package managers.

QEMU allows you to run multiple operating systems or applications on the same physical hardware, providing flexibility and resource utilization that can be useful in various situations.

What Is Hyper-V?

enable hyper v Windows 11 Home

Hyper-V is a virtualization platform developed by Microsoft, allowing you to create and run virtual machines on a Windows host system. It is included in certain versions of Windows and Windows Server and is used in enterprise environments due to its robust feature set and integration with other Microsoft products.

Hyper-V has several features designed to support enterprise use cases, including support for high availability, live migration, and support for multiple processor architectures. It also integrates with other Microsoft products, such as System Center, for management and monitoring purposes. You might need to enable Hyper-V if you're running Windows 11.

QEMU vs. KVM: What's the Difference?

QEMU and KVM are both open-source virtualization solutions commonly used in Linux environments. QEMU, short for Quick Emulator, is a generic and open-source machine emulator that can run various operating systems.

KVM (short for Kernel-based Virtual Machine) is a virtualization infrastructure for the Linux kernel that allows you to run multiple virtual machines on a single physical host.

The key difference between QEMU and KVM is that QEMU is a software-based virtualization solution (type 2 hypervisor), while KVM is a hardware-based virtualization solution (type 1 hypervisor). This means that KVM uses the hardware virtualization capabilities of the host machine's CPU to run virtual machines, while QEMU relies on software emulation to run virtual machines.

As a result, KVM tends to be more efficient and performant than QEMU but is also more hardware-dependent.

VirtualBox vs. Hyper-V: The Differences

VirtualBox and Hyper-V are proprietary virtualization solutions commonly used in Windows environments.

VirtualBox is a type 2 hypervisor, while Hyper-V is a type 1 hypervisor. The key difference between VirtualBox and Hyper-V is that VirtualBox is a cross-platform virtualization solution, while Hyper-V is only available on Windows. This means that VirtualBox can be used to run virtual machines on a variety of different operating systems, while Hyper-V is only available on Windows.

Another difference is that Hyper-V is designed for enterprise use, while VirtualBox is more geared towards individual and small business use cases.

QEMU vs. VirtualBox

QEMU and VirtualBox are both open-source and cross-platform virtualization solutions. However, there are some key differences between the two. QEMU is a software-based virtualization solution, while VirtualBox makes use of software and hardware virtualization to run virtual machines. As a result, VirtualBox tends to be more efficient and performant than QEMU, but it is also more specialized and may not be as flexible.

Remember there are multiple ways to run a virtual machine on Linux.

Choose the Best Virtualization Solution for You

QEMU, VirtualBox, KVM, and Hyper-V are all virtualization solutions that work differently to serve the same purpose, i.e., allow you to set up and run multiple OSes on a single system. When it comes to virtualization solutions, there's another concept that is superseding traditional virtualization in multiple ways.

Containerization is an advanced virtualization technology that does much of what traditional virtualization software offers but uses fewer resources and is much faster and more portable. If you want to run your applications on multiple environments on the fly, you should check out containerization solutions like Docker.