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Installing VirtualBox

As I said in the previous section, I've chosen to mostly use CentOS for the recipes in this book. Hopefully, this gives you a good baseline for learning about Linux Administration, but also gives you a bit of a head start if you plan on going for any of the Red Hat exams.

Instead of requiring you to have a spare laptop handy, or renting a server somewhere, I'm going to advocate using VMs for testing and running through the examples given.

VMs are exactly as they sound – a way of virtualizing computer hardware on one or a cluster of physical machines, thus allowing you to test, break, and play to your heart's content, without risking rendering your own computer unbootable.

There are many ways of creating a VM: macOS has xhyve, Windows has Hyper-V, and Linux has a native implementation called Kernel Virtual Machine (KVM).

KVM (along with libvirt) is the technology that you will come across most often in the Linux virtualization space. It forms the basis of popular technologies, such as Proxmox and OpenStack, while providing near-native speeds.

Another way of creating and managing VMs is a program called VirtualBox, which is now developed by Oracle. The nice thing about this software, and the reason I shall be using it here, is that it's cross-platform, being produced for macOS, Windows, and Linux.