QEMU vs VirtualBox: What’s the difference?

Virtualization is a helpful technology that has exploded in popularity and accessibility in the last decade. There are many great reasons to use virtual machines, such as having a test environment separate from your host operating system. It also allows you to run multiple operating systems or Linux distros simultaneously – all inside of their own sandboxed environment, with optional network interconnectivity among your machines.

When it comes to virtualization, users of Linux systems have many choices. QEMU and VirtualBox are two of the most popular hypervisors on Linux. But unless you are already familiar with virtualization and the various choices of different hypervisors, you may be wondering about the difference. In this tutorial, we will look at the differences between QEMU and VirtualBox, discuss their pros and cons, and help you decide which one is better for various virtualization needs on Linux.

In this tutorial you will learn:

  • What is QEMU? What is VirtualBox?
  • Pros and Cons of QEMU and VirtualBox
  • The difference between QEMU and VirtualBox
  • Which hypervisor should I use, QEMU or VirtualBox?
QEMU vs VirtualBox: What's the difference?
QEMU vs VirtualBox: What’s the difference?
Software Requirements and Linux Command Line Conventions
Category Requirements, Conventions or Software Version Used
System Any Linux distro
Software QEMU, Oracle VirtualBox
Other Privileged access to your Linux system as root or via the sudo command.
Conventions # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
$ – requires given linux commands to be executed as a regular non-privileged user

QEMU and VirtualBox

QEMU is short for Quick EMUlator. As its name implies, it can be used as an emulator, but also as a hypervisor. As an emulator, it allows you to run software that would normally not be possible to run on your current operating system because of compatibility. As a hypervisor, it allows you to create and manage virtual machines. It integrates quite seamlessly with KVM (Kernel-based Virtual Machine) which yields amazing performance results for your virtual machines.

KVM Kernel-based Virtual Machine) is the type 1 hypervisor built into every Linux kernel since version 2.6.20. QEMU and VirtualBox are type 2 hypervisors that can utilize KVM (or other type 1 hypervisors, in the case of VirtualBox) to allow virtual machines direct access to your system’s hardware.

Oracle VirtualBox is a hypervisor. Unlike QEMU, it is not an emulator; however, it has a strong track record as a user friendly hypervisor that does a good job of running a wide variety of operating systems. It can be easily installed on most systems, and in practical use scenarios has better luck with cross compatibility between operating systems such as Windows and Linux.

VirtualBox Pros and Cons

VirtualBox Pros:

  • Easy to use for users of all levels
  • More features; neatly organized menus make them easy to find and toggle
  • Compatible with Linux, BSD, Windows, and MacOS

VirtualBox Cons:

  • Slower than QEMU
  • Hypervisor only; no emulation capabilities
  • Higher resource usage

QEMU Pros and Cons

QEMU Pros:

  • Close integration with KVM; More performant than VirtualBox
  • Free and open source
  • Can work as an emulator as well as a hypervisor

QEMU Cons:

  • Not as user friendly as VirtualBox
  • Takes a little more effort to set up, especially for new users
  • Less cross compatible than VirtualBox

The Difference Between QEMU and Oracle VirtualBox

Ease of use: When it comes to user friendliness, you really can’t beat Oracle’s VirtualBox. You can install it with only a single package, and it only takes a few minutes to get a virtual machine up and running – even for a novice user. QEMU is also not exceptionally difficult by any means, but it could be a rough choice as someone’s first foray into virtualization.

CPU architectures: VirtualBox only works on x86 CPU architecture. This will not be a problem for most users, as the vast majority of systems come with the usual 64 bit Intel or AMD CPU. QEMU works with many CPU architectures, including x86, ARM, Alpha, and SPARC. This makes it the superior choice for IoT and similar devices like Raspberry Pi.

Performance: QEMU takes the cake when it comes to performance. For end users wetting their feet with virtualization, the performance difference between QEMU and VirtualBox will be quite neglible. More seasoned users are sure to notice how much speedier QEMU can run virtual machines, all while utilizing less system resources.

Features: QEMU is both an emulator and hypervisor. VirtualBox is just a hypervisor. Apart from this, their feature set mostly boils down to the various architectures and operating systems that both support, but we have already covered all of that in the above sections.

Compatibility: Although both can be used across different operating systems, VirtualBox is the much better choice if you want to port virtual machines across systems like Windows, Linux, and MacOS. For hardware compatibility, QEMU will work much better with Linux, as it is closely integrated with KVM. QEMU also sports much better CPU architecture compatibility, as mentioned earlier.

Closing Thoughts

In this tutorial, we learned about the difference between QEMU and Oracle VirtualBox. While each choice contains their own pros and cons, selecting the right tool for you will depend on your personal preferences and virtualization goals. Both programs work similarly in many ways, but also have a few unique features not found in their competition. Hopefully our guide has made the differences clear, and allowed you to select the best tool for you.

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