Why VirtualBox is my goto Hypervisor

I first started using VirtualBox many years ago, and it quickly became my favorite virtualization platform. What drew me in initially was its open-source nature. The base package, which includes both the source code and binaries, is licensed under GPL version 3.

VirtualBox is impressively versatile. It runs on Linux, macOS (both Intel and ARM architectures), Windows, and even Solaris. Since its initial release in 2007, it has undergone continuous development, steadily improving with each iteration. The most recent stable release, version 7.2.4, was rolled out in October of this year, demonstrating that the project is still very much alive and evolving.

For me, VirtualBox has always been more than just a tool—it’s a sandbox for exploration. I use it to test new Linux distributions, experiment with Windows releases, and even help others with their computing needs.

Real-World Use Case: Helping My Dentist

A recent example highlights just how practical VirtualBox can be. My dentist asked me to help set up a Windows Server 2025 file server for his practice management system. Instead of risking his production environment, I spun up a virtual machine in VirtualBox to test configurations and ensure everything worked smoothly before deploying it on his actual hardware.

This kind of flexibility is invaluable. VirtualBox enables you to simulate real-world environments without the cost or risk associated with physical machines. Whether you’re a hobbyist tinkering with new operating systems or a professional preparing for deployment, VirtualBox provides a safe and efficient playground.

My Daily Driver Setup

To provide some context, my primary workstation is a System76 Meerkat running Linux Mint 22.2. It’s a compact yet powerful machine, equipped with 32 GB of RAM and a one-terabyte NVMe drive. This hardware setup makes virtualization a breeze. With plenty of memory and fast storage, I can run multiple virtual machines simultaneously without noticeable lag.

Installing VirtualBox on Linux Mint is a straightforward process. From the command line, it’s as simple as:

$ sudo apt install virtualbox

For Fedora users, the installation command is slightly different:

$ sudo dnf install virtualbox

Within minutes, you can have VirtualBox up and running, ready to host any operating system you want to experiment with.

The Dreaded VT-x Error

Of course, no journey in tech is without its hiccups. When I first launched VirtualBox on my Linux Mint system, I encountered a frustrating error message:

VT-x is being used by another hypervisor (VERR_VMX_IN_VMX_ROOT_MODE).
VirtualBox can't operate in VMX root mode. Please disable the KVM kernel extension, recompile your kernel and reboot (VERR_VMX_IN_VMX_ROOT_MODE).

At first glance, this doesn’t look very safe. Essentially, the error indicates that another hypervisor—specifically, KVM (Kernel-based Virtual Machine)—is already utilizing the VT-x virtualization extensions provided by the CPU. Since VirtualBox also relies on VT-x, the two hypervisors clash, preventing VirtualBox from running correctly.

The Solution: Disabling KVM

Thankfully, the fix turned out to be relatively straightforward. After some searching online, I found a solution that worked perfectly. By unloading the KVM Intel kernel module, VirtualBox can reclaim access to VT-x and function normally.

Here’s the command that solved the problem:

$ sudo modprobe -r kvm_intel

Once executed, VirtualBox launched without issue—no kernel recompilation, no reboot—just a quick command to disable the conflicting module.

This solution has become part of my routine whenever I encounter the VT-x error. It’s a minor inconvenience, but one that’s easy to manage once you know the trick.

Final Thoughts

My journey with VirtualBox has been one of discovery, problem-solving, and practical application. From testing new Linux distributions to helping my dentist set up a Windows Server, VirtualBox has proven itself time and again as a reliable and versatile virtualization platform.

If you haven’t tried VirtualBox yet, I highly recommend giving it a spin. Whether you’re running Linux, macOS, Windows, or Solaris, VirtualBox is ready to help you explore the digital frontier.