Installing Ubuntu
Ubuntu Server is the operating system Koios runs on. This page walks through its installer one screen at a time. No prior Linux experience is assumed.
Allow about 20 minutes. Most of it is waiting.
Which Version
Use Ubuntu Server 26.04 LTS. Koios also runs on 24.04 LTS and 22.04 LTS if you have a site standard to match.
LTS means Long Term Support: security updates for five years. Do not use a non-LTS release — they are supported for nine months, and you do not want an operating system upgrade forced on a production machine every nine months.
Download the server image, not the desktop image. Koios is administered entirely through a browser on your own computer, so the machine needs no graphical desktop, and installing one only adds software to keep patched.
Getting the Installer onto the Machine
On a virtual machine, you already attached the .iso file when you created it. Nothing to do.
On a physical machine, write the .iso to a USB stick using an imaging tool such as Rufus or balenaEtcher, then boot the machine from it. Most machines need a key pressed during startup to choose a boot device — commonly F12, F11, or Esc — and many also need Secure Boot disabled in the firmware settings first.
Working Through the Installer
The installer is keyboard-driven: arrow keys to move, Space to tick a box, Tab to reach the buttons at the bottom, Enter to confirm. The mouse does nothing.
Language and keyboard
Choose your language, then your keyboard layout. If you are unsure of the layout, the installer can identify it by asking you to press a few keys.
Type of install
Choose Ubuntu Server (minimized) if it is offered, otherwise the standard Ubuntu Server.
The minimized variant leaves out documentation, editors, and interactive tools intended for people who work at the machine directly. Koios needs none of it, and everything left out is something that would otherwise need patching.
Leave any additional snap packages the installer offers unticked. Koios needs none of them.
Network
Set the machine's permanent address here. This screen is the easiest place to do it — the values go into labeled fields, and you can correct them as many times as you like before moving on.
Doing it now also means you are finished with this console. Once the machine has a fixed address and an SSH server, you connect from your own computer for everything that follows, where copy and paste work.
Fill in your settings below and this page will show them in place of the placeholders, here and on every other installation page.
Use your own values
Enter your settings and the commands throughout the installation pages will show them instead of placeholders. They stay in this browser — nothing is sent anywhere, and nothing is saved to Koios.
The machine picks up a temporary address automatically. To replace it, select your network adapter, choose to edit its IPv4 configuration, and change the method from automatic to manual. Four fields appear:
Save the adapter, and confirm the screen now shows the address you chose. If it does not look right, open it again and fix it — nothing is committed until you continue past this screen.
If you do not have the network details yet, leave the automatic address in place and carry on — you can set a permanent one afterwards from Network Configuration, though you will be typing it into a text file rather than a form.
If the adapter shows no address at all, the machine is not reaching the network. On a virtual machine that almost always means the adapter is on the wrong virtual switch — External on Hyper-V, or bridged elsewhere. Fix it before continuing; the installer needs the network to fetch updates.
Proxy and mirror
Leave the proxy blank unless your site requires one to reach the internet. Accept the mirror the installer suggests.
Storage
Accept Use an entire disk, then confirm the summary on the following screen.
Guided partitioning makes sensible choices, and Koios has no special storage layout requirements. Two points worth knowing:
- The installer may leave part of a large disk unallocated by default. If the summary shows a root partition much smaller than the disk, adjust it to use the full space — Koios stores historical data there and running out of room is disruptive to fix later.
- Encryption and LVM are optional. Neither affects Koios.
The installer warns that it is about to erase the disk. On a new virtual machine there is nothing to lose. On a physical machine, check you are erasing the machine you think you are.
Profile
Enter your name, a name for the machine, a username, and a password.
The machine name is what appears at the command prompt, so something descriptive helps: koios-plant1 beats ubuntu-server. The username and password are yours for logging into the machine, and are unrelated to the Koios login you will use in the browser.
Ubuntu Pro
Skip this. It is an optional Canonical subscription and Koios does not need it.
SSH
Tick "Install OpenSSH server." Do not skip this one.
Together with the address you set two screens ago, this is what gets you off the console. Without it, every remaining command in this guide has to be typed by hand into a window with no copy and paste — and one of them is an indentation-sensitive configuration file.
It is a single tick, it is easy to miss, and noticing later means going back to the console to install it.
Leave the SSH key import option alone.
Featured server snaps
Select nothing. Koios needs none of these, and each one is more software to maintain. Tab past to continue.
Install
The installer copies files and then fetches updates. This takes several minutes, and the update phase can sit apparently motionless for a while — let it finish rather than interrupting it.
When it is done, choose Reboot Now.
If it asks you to remove the installation medium and press Enter, do so — eject the USB stick on a physical machine. On a Hyper-V virtual machine you can ignore it; it boots from disk regardless.
First Login
After the reboot you get a text login prompt. Enter the username and password you chose.
There is no desktop, and no visible feedback while typing the password. That is normal.
Confirm the machine took the address you gave it:
You should see it next to your network adapter, as <your-server-ip>/24.
Move to Your Own Computer
This is the last thing you do at the console. From your own machine — Terminal on macOS or Linux, PowerShell or Windows Terminal on Windows:
It asks once whether to trust the machine — answer yes — then for your password.
Everything from here can be pasted rather than typed, which matters: the remaining steps are long commands where a typo is easy to make and hard to spot.
Refused or timed out? Check the address with ip -br addr at the console, and confirm you ticked Install OpenSSH server during the install. If you missed it, run sudo apt update && sudo apt install -y openssh-server there, then try again.
Once connected, update the system:
It asks for your password the first time you use sudo. This installs security updates released since the installer image was built, and can take a few minutes.
If it reports that a restart is required:
Your session ends when the machine restarts. Wait a moment and connect again.
What's Next
- Network Configuration: confirm the address, open the ports Koios needs