Phase 1 · Free

1.4 Installing Ubuntu

This is the part where you actually build the machine. You will make a virtual computer, give it a slice of your real computer's memory and disk, put the Ubuntu installer in its virtual drive, and install.

90 minPhase 1: Get a Machine RunningFree

Phase 1. Lesson 4 of 5. About 60 to 90 minutes, most of it waiting.

Plain entry

This is the part where you actually build the machine. You will make a virtual computer, give it a slice of your real computer’s memory and disk, put the Ubuntu installer in its virtual drive, and install. When you finish, you will have a full Linux desktop running in a window, and you can break it as many times as you want without touching your real files.

The VMA software-based emulation of a complete computer that runs its own operating system and applications, isolated from the host hardware. Read more → path is the default for this course. It costs nothing, needs no spare hardware, and lets you take snapshots so a mistake is never fatal. If you have a spare PC and want the real thing, the bare-metal section is at the end.

Terms

  • HypervisorSoftware that creates and manages virtual machines by abstracting physical hardware resources and allocating them to isolated guest operating systems. Read more →: the software that runs virtual machines. VirtualBox and UTM are hypervisors. See hypervisor.
  • Host / guest: the host is your real computer. The guest is the VM.
  • Virtual disk: a file on the host that the guest sees as a whole hard drive. VirtualBox uses .vdi files.
  • PartitionA defined section of a physical disk that the operating system treats as a separate unit, each usually holding its own filesystem. Read more →: a section of a disk set aside for one purpose. The installer creates them for you.
  • FilesystemThe structure an operating system uses to organize data on a disk into files and folders, tracking names, sizes, permissions, and where each piece is stored. Read more →: the way data is organized on a partition. Ubuntu uses ext4 by default.
  • SnapshotA saved, point-in-time state of a virtual machine or storage volume that you can roll back to if a change goes wrong. Read more →: a saved state of a VM you can roll back to.
  • sudoA Linux command that runs a single command with administrator (root) privileges, after checking that your account is allowed to do so. Read more →: the command that runs something as the administrator. Your first user can use it.

Before you start

Minimums for a smooth desktop VM: 4 GB RAMRandom Access Memory: the fast, temporary working memory that holds the programs and data a computer is using right now, cleared when power is lost. Read more → to give the guest (8 GB on the host), 2 CPU cores, 30 GB free disk. Ubuntu’s own minimum list is linked below. If your host has only 8 GB total, give the guest 4 GB and close your browser while installing.

Virtualization must be on in your host’s firmwareLow-level software stored on a chip inside a device that controls the hardware directly and runs before any operating system loads. Read more →. On Windows, open Task Manager, Performance, CPU, and look for “Virtualization: Enabled.” If it says Disabled, turn on Intel VT-x or AMD-V (sometimes called SVM) in firmware setup (lesson 1.2).

Path A (default): VirtualBox on Windows, Linux, or Intel Mac

  1. Download VirtualBox (7.2 at time of writing) from https://www.virtualbox.org/wiki/Downloads and install it with defaults.
  2. Click New.
    • Name: bnlc-ubuntu
    • ISO Image: your verified Ubuntu ISO from lesson 1.3
    • Check Skip Unattended Installation. You are here to see every step.
  3. Hardware: Base Memory 4096 MB, Processors 2, check Enable EFI.
  4. Hard Disk: Create a virtual hard disk now, 30 GB. Leave it dynamically allocated (the file grows as needed).
  5. Finish, then Start.

Path A2: UTM on an Apple silicon Mac

  1. Download UTM from https://mac.getutm.app/ (free from the site; the App Store copy costs money and is the same app, so use the site).
  2. Create a New Virtual Machine, choose Virtualize, then Linux.
  3. Boot ISO Image: your ARM64 Ubuntu ISO. Memory 4096 MB, 2 cores, 30 GB disk.
  4. Save, then press Play.

The installer (same on every path)

  1. Pick Try or Install Ubuntu in the boot menu.
  2. Choose language and keyboard.
  3. Connect to the internet (the VM uses the host’s connection automatically).
  4. Choose Interactive installation, then Default selection.
  5. Check Install third-party software only on bare metal (it pulls drivers you might need). In a VM it does not matter.
  6. Disk setup: Erase disk and install Ubuntu. In a VM, this erases only the empty virtual disk. Your real files are not touched.
  7. Create your user. Use a real password you will remember. This user can use sudo.
  8. Time zone, then Install. Wait.
  9. Restart now. If it asks you to remove the installation medium, press Enter. VirtualBox usually ejects it for you.

Prove it worked

Log in, open a terminal with Ctrl+Alt+T, and run:

uname -a

Expected output shape (environment-specific):

Linux bnlc-ubuntu 7.0.0-14-generic #14-Ubuntu SMP PREEMPT_DYNAMIC <build date> x86_64 GNU/Linux

The kernel number and build date will differ, and go up after updates. The hostname is whatever you chose. On a Mac the end reads aarch64.

Then:

lsb_release -a

Expected output:

Distributor ID: Ubuntu
Description:    Ubuntu 26.04 LTS
Release:        26.04
Codename:       resolute

If you installed from a point release ISO, or after updates, Description reads Ubuntu 26.04.1 LTS (or higher). resolute is the codename of 26.04 (Resolute Raccoon).

Bring it fully up to date:

sudo apt update && sudo apt upgrade -y

It asks for your password. Nothing appears while you type it. That is normal.

Take your first snapshot

Shut the VM down (top-right menu, Power Off). In VirtualBox, select the VM, click the menu icon next to it, Snapshots, Take, name it clean-install. In UTM, snapshots are not in the main interface; instead, right-click the VM, Clone, and keep the clone as your clean copy. You will use this backup in Phase 4.

Optional quality of life

VirtualBox Guest Additions let the window resize and the shared clipboard work. The kernel side of the guest drivers ships with Ubuntu, so resizing often works out of the box. If the screen will not resize or the clipboard does not work, install the guest tools and reboot:

sudo apt install -y virtualbox-guest-utils

Ubuntu 26.04 desktop runs on Wayland only, so virtualbox-guest-x11 (which pulls in the X server) is not the first choice. If the packaged tools do not fix it, use Devices, Insert Guest Additions CD image in the VirtualBox menu and run the installer from the CD. List the available packages with apt search virtualbox-guest.

Path B (optional): bare metal

This erases the target machine’s disk. Back up anything you care about first.

  1. Plug in your bootable USB (lesson 1.3).
  2. Power on and open the one-time boot menu (lesson 1.2 table). Pick the USB entry that says UEFI.
  3. Run the same installer steps above. At disk setup, Erase disk and install Ubuntu wipes the whole internal drive.
  4. If the machine boots straight back to Windows, the boot order still puts the internal disk first. Go into firmware setup and move the USB up, or use the one-time menu again.
  5. Common snags: no Wi-Fi in the installer (plug in Ethernet, then install third-party drivers), black screen with NVIDIA cards (at the boot menu press e, add nomodeset to the line starting linux, then Ctrl+X), USB does not show up (re-flash it, try a USB 2.0 port, turn off “Fast Boot” in firmware).

Why it works this way

Each installer choice has a reason. EFI on, because real hardware sold today boots UEFI and you want your practice machine to match. A snapshot right after install, because it gives you a known good state to return to, which is what lets Phase 4 break things on purpose. Updating first, because the ISO is frozen on its release day and every patch since then is waiting. When an install fails, the question is always the same: which of these steps did not finish? The installer log and the error on screen tell you where it stopped.

Self-check

  1. Why is the VM path safe for your real files?
  2. What does “Enable EFI” in VirtualBox change?
  3. What do you type, and what do you expect to see, to prove the install?
  4. Why take a snapshot right now?

Answers: (1) The installer erases only the virtual disk file. (2) The VM gets UEFI firmware instead of legacy BIOS, like a modern PC. (3) uname -a, a line starting with Linux and your hostname. (4) So you can roll back to a clean system when you break it later.

Sources