How QEMU works

Are you passionate about computer virtualization and have you heard about the existence of a very powerful emulation software called QEMU that seems to be very fast? Well, you have come to the right place, in this article, without falling too much into technicalities that could complicate your ideas, I will explain how QEMU works and give you some hints on the QEMU configuration.

I anticipate right away, however, that QEMU turns out to be slightly more complicated for less experienced users than other virtualization software (for example VMWare or VirtualBox).

How QEMU works

QEMU (short for Quick EMUlator) is a completely free emulation software (GNU GPL license) that was created for Linux systems but was then also ported to Mac and WIndows. Its strengths are its emulation power and performance; its biggest disadvantage is that there is no real graphical interface to use it so it is not really within everyone’s reach.

Considered by many to be the fastest virtualization system there is. With QEMU you can virtualize X86 computers but also SPARC, PowerPC and ARM; in particular it is possible to emulate for example WIndows for arm on MAC with M1 processor.

On Linux machines QEMU is also able to emulate single processes instead of an entire virtual machine, that is, it allows you to emulate processes and applications created for a different CPU.

QEMU is also widely used to test so-called live images ; that is, real distributions of software and operating systems that can be booted directly from USB or CD. With QEMU it is possible to test these live images without the need to restart the computer and run it from external media.

QEMU allows you to take snapshots exactly like other virtualization software and to import images of machines generated by other software (for example machines from VMWARE).

Now you know roughly how QEMU works but you still don’t know how QEMU configuration works and how to use it. First of all you can download QEMU from this page by selecting your operating system (make sure you download the pre-compiled binary files and not the QEMU source files).

QEMU does not offer graphical interfaces natively and everything happens through the command line; however many 3rd party graphical interfaces have been developed to simplify their use; I recommend AQEMU whose graphics are very reminiscent of the virtual box and which allows you to manage and configure all the virtual machines created with QEMU.

As I told you QEMU is very complex to use and its correct installation varies from the operating system (Host) in which it will be installed; for its installation then I refer you to the official pages of QEMU and let you know immediately that they are all in English.

In conclusion, QEMU is a powerful multi-platform emulator that allows you to virtualize different operating systems with excellent performance as well as run live images. The software is more difficult than other products (for example Virtual Box) so it is recommended to be used only by expert users.