3.4 Build a practice VM

Time to build a computer out of settings. This VM is a rehearsal: you'll install Ubuntu Server on it, and in the next lesson you'll snapshot it, destroy it, resurrect it, and then delete it. Knowing it's disposable is the point. Nobody learns the piano at a recital.

Create the VM

In Workstation: File > New Virtual Machine. Take the Custom path if it's offered with defaults otherwise, and when the wizard asks, answer like this. Every choice teaches something, so the reasons ride along:

• Installer: point it at your Ubuntu Server ISO from 3.3. If the wizard offers an "Easy Install" that promises to answer the installer's questions for you, decline it. The installer's questions are the curriculum.
• Name: practice01. Boring names sort well; you'll appreciate this when there are seven VMs.
• Location: C:\VMs\practice01 (or ~/VMs/practice01 on Linux and macOS). The wizard will suggest somewhere in your Documents or user profile, and you're overriding that on purpose, per the folder rules in lesson 3.3. Make sure the path ends in the machine's own name so this VM gets a folder to itself.
• CPU: 2 cores. Enough to feel responsive, small enough to share.
• RAM: 2 GB. A headless Ubuntu Server idles far below this.
• Disk: 25 GB, and here's the setting worth understanding: the hypervisor offers to allocate space now or let the disk grow as it's used (thin provisioning, in datacenter vocabulary). Choose grow-as-used. The guest sees a 25 GB disk either way, but the file on your laptop only occupies what's really written, which is how your machine from 0.6 fits a whole lab.
• Network: leave it on NAT. Module 4 is entirely about what that means and what the alternatives are; today the VM just needs the internet.

VirtualBox difference

Same decisions, different wizard: Machine > New, and untick any "unattended install" option so you get the real installer. The first screen has both the name and the Folder where the machine is stored; point that at C:\VMs (VirtualBox appends the machine name to it, giving you C:\VMs\practice01). RAM and CPU live on the following screens; pick "dynamically allocated" for the disk, which is VirtualBox's name for grow-as-used. Networking defaults to NAT already.

Install Ubuntu Server

Power the VM on and it boots your ISO exactly as a physical server would boot a DVD. The installer is text-mode: arrow keys, tab, enter. It looks austere and it teaches well. Walk it like this:

1. Language and keyboard: yours.
2. Installation type, network, proxy, mirror: accept the defaults. (The installer configures the network automatically via that NAT connection; noticing that will pay off in Module 4.)
3. Storage: use the entire (virtual) disk, defaults throughout, and confirm. You're erasing a 25 GB file, not your laptop; the guest can't see your real disk at all.
4. Profile: your name, practice01 as the server's name, a username you'll remember, and a password you'll type a lot. Lab passwords can be simple; production passwords can't; know which world you're in.
5. OpenSSH server: tick yes. One habit worth installing every time on every server, because a server you can only reach from its own console isn't really a server.
6. Skip the featured snaps list, let it install, and reboot when offered. If it complains about the CD-ROM on reboot, that's the ISO still "in the drive"; the hypervisor usually handles it, and disconnecting the ISO from the VM's settings fixes it if not.

Log in at the console with the account you created. Look around for a minute; this is the same OS your permanent lab server will run, and Module 6 goes deep on it. For today, prove it's a real computer on a real network:

# Ubuntu's IP address on the NAT network. Yours will differ from
# your neighbor's, and Module 4 explains where it came from.
ip addr

# A round trip to the outside world, four times.
ping -c 4 ubuntu.com

A machine you built from settings just spoke to the internet. Leave it running and go straight into lesson 3.5, where you'll learn why it was never in any danger.