Installing the Guest Operating System

VirtualBox creates guest machines that run on top of a host machine. The host machine is the machine running VirtualBox. It hosts various virtual machines running as guests inside of VirtualBox. Once we define a virtual machine, we install an operating system, much like installing a real operating system on a computer. Let’s install Ubuntu on this machine using the disk image we downloaded.

Installing Ubuntu on our virtual machine

When we first start our virtual machine, VirtualBox detects that there’s no operating system and prompts us to install one. We start the machine, select our Ubuntu virtual machine from the list of machines, and press the green “Start” button at the top of the VirtualBox interface.

VirtualBox prompts us for a virtual disk or optical disk that holds the installation media. Select the folder icon at the bottom right to open a file dialog. We navigate to our Downloads folder and select the Ubuntu ISO file we downloaded. Once we’ve selected the installation media, we press the “Start” button.

The machine boots, and the Ubuntu installation program starts, displaying a welcome screen. Choose the “Install Ubuntu” option on the welcome screen.

We’re prompted to select our keyboard layout from the list. We click “Continue” once we’ve made our selection.

Installer

The installer asks if we’d like to do a normal installation or a minimal installation. We choose to do a minimal installation because we can install other things later if we decide we want them. It also asks if we’d like to download updates and install third-party software during the installation. Installing updates during the installation can prevent some incompatibility issues between Ubuntu and VirtualBox. The third-party software option tells the installer to include packages with additional restrictive licensing terms, such as Flash and MP3 support. It’s better to avoid using third-party software.

On the “Installation type” screen, we see this screen asking us to erase our disk.