Server editions

Nubo OS Server is the server edition of Nubo OS 1, based on Ubuntu 26.04 LTS with Ubuntu’s text installer, kernel and packages. It adds a small set of packages for a safer starting point. There are four editions that differ only in which packages they add to a common core.

Which edition should I choose?

Edition	Package	Adds to the core	Choose it for
Server	nubo-server-base	Unattended upgrades, fail2ban, needrestart, curl, htop, less, vim-tiny	A general-purpose server
Virtualization	nubo-incus	Server plus Incus, ZFS tools, bridge utilities and QEMU	Virtual machines and system containers
Containers	nubo-podman	Server plus Podman, Buildah, Skopeo, uidmap and passt	Running containers
Edge	nubo-edge	The core plus unattended upgrades only	Small boards and appliances

Because the editions share a core, you can add another edition’s package later, for example nubo-podman on a Server machine.

What do the defaults do?

• The system calls itself “Nubo OS Server 1”.
• SSH without root login, and a firewall closed except for SSH. Password login over SSH stays on until you install an SSH key, so a new machine is never locked out. Turn it off yourself afterward.
• Time sync with chrony using Cloudflare NTS and pool.ntp.org.
• Kernel network hardening, AppArmor, and automatic security updates. Automatic reboots are off.
• No crash reports, news or Ubuntu Pro adverts sent to Canonical. Package downloads go through Nubo Cumulus with Ubuntu’s servers as fallback.

What are the limits?

The server images are built for amd64 and arm64 but have had limited testing on physical hardware, and the Virtualization, Containers and Edge editions have not been tested on a running machine from a Nubo image. Running nubo-server-firewall again deletes your own firewall rules.

You administer a Nubo OS server with the usual Ubuntu tools: apt, systemctl, journalctl, netplan and ufw. See the Ubuntu Server documentation.