Comparing KVM vs QEMU

KVM vs QEMU
KVM vs QEMU

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As an IT administrator, one of your jobs may be providing cost-efficient solutions while running multiple applications simultaneously. Here virtualization comes into play where you can shrink your IT management into a single console. There are many virtualization technologies for this purpose, and some worth noting include KVM or QEMU.

All virtualization technologies offer the same purpose: the allowance to run multiple operating systems on a single physical machine.

But, where there are similarities, there are differences too, which let one outperform the other based on the user’s requirements. By the end of this article, you will be able to differentiate between KVM and QEMU and choose the one which fits your needs.

What Do KVM And QEMU Do

KVM (Kernel-based Virtual Machine) is an open-source virtualization technology built into Linux, whereas QEMU (Quick EMUlator) is a machine emulator that can run operating systems and programs for one machine on a different one.

KVM and QEMU are popular hypervisors that allow you to manage and interact with your virtual machines. Simply ignoring these or any other hypervisors is not an optimum solution when your goal is to perform multiple operations while minimizing costs.

Comparing KVM And QEMU

One common misconception when it comes to choosing virtualization technologies in this domain is that most people assume both KVM and QEMU to be the same when it’s not. Both have significant differences between them, including the hypervisor type, interface, performance, installation, and supported operating systems. These are discussed below:

Hypervisor

KVM is a type 1 hypervisor that offers a hardware-based virtualization solution, whereas QEMU is a type 2 hypervisor that offers a software-based virtualization solution.

To elaborate, KVM uses the abilities of hardware virtualization of the host machine’s CPU to operate virtual machines, while QEMU counts on software emulation to operate virtual machines. Type 1 hypervisor and Type 2 hypervisor are also comprehended as bare-metal hypervisor and hosted hypervisor, respectively.

Here, the Type 1 hypervisor is in charge of running commands on the host’s hardware, whereas the Type 2 hypervisor forms virtual environments on numerous devices while running on a traditional operating system.

Interface

Close-up photo of male hands with laptop

The interface of KVM is not friendlier to the end-user. While it may seem hectic on first usage, you may surely get the hang of it in the long run. On the other hand, QEMU is more user-friendly and easier for a newbie. That is why it is usually recommended to get a hold of QEMU before switching to KVM.

Performance

Since KVM runs directly on the hardware (baked into Linux Kernel), its performance is unmatchable! However, it is not as feature-rich as QEMU (which can work as an emulator and hypervisor both). On the other hand, where QEMU has close integration with KVM, there is a performance drop because of this indirect pathway to the actual hardware.

Installation

Where KVM is preinstalled on Linux-based systems, QEMU requires installation and configuration to set up before actual usage of it. This is just one disadvantage from a total of two for QEMU installation. The second one is its complexity in installing it, another drawback.

Note: You can refer to this link if you’re willing to download and install QEMU for your system.

Operating Systems

The KVM is primarily built for Linux OS; it is only available for Linux systems and designed to operate on x86-based processor architecture. However, QEMU can operate on multiple operating systems, including Linux, macOS, and Windows. This further aids in its popularity as not everyone operates the Linux operating system.

Set of top brand operating system logos

Verdict

While both virtualization technologies offer almost the same purpose, Kernel-based Virtual Machine is recommended over Quick EMUlator if you’re on a Linux Operating System. As a Linux user, QEMC is only recommended if you’re completely new to the world of virtualization.

With that said, if you’re a non-Linux user, Quick EMUlator is one of your only options. However, don’t feel left behind, as where QEMU lacks speed, it provides a number of features along with a GUI. Here is a table that lists all the comparisons we’ve listed above:

FeaturesKVMQEMU
HypervisorOffers hardware-based virtualization solutionOffers software-based virtualization solution
InterfaceDifficult to use for newcomersProvides a GUI that makes managing your virtual machines much easier
Overall PerformanceFast- Slower than KVM but fast overall
- Can be used as an Emulator and Hypervisor both
InstallationPreinstalled on LinuxNeed to download and install manually
Platforms SupportedOnly LinuxLinux, MacOS, and Windows

Conclusion

To end with, both virtualization technologies deliver the same functionality from a broader perspective. However, depending on your operating system, one or both may be compatible, but your needs may assist you in selecting the right technology, and we hope we’ve made this obvious with our comparison. Save our blog for articles related to similar domains in the future!