How to Install Ubuntu Server 26.04 LTS — Complete Production Guide

01 Release Overview & What’s New in 26.04

Ubuntu 26.04 LTS, codenamed Resolute Raccoon, landed on April 23, 2026. It is an LTS (Long-Term Support) release — Canonical commits to five years of standard security updates (through 2031) and an additional five years via Ubuntu Pro, bringing total coverage to a full decade.

For server administrators, this release is significant. It ships the Linux 7.0 kernel, removes cgroup v1 entirely (cgroup v2 is now mandatory), replaces the traditional sudo binary with the memory-safe Rust rewrite sudo-rs, and introduces native first-class support for NVIDIA CUDA and AMD ROCm — making it an excellent AI/ML workload platform out of the box.

02 Which Ubuntu Server Version for Which Configuration?

Not every server should run the newest LTS. The table below maps server use cases and hardware profiles to the recommended Ubuntu release, so you can make an informed decision before you begin.

03 Prerequisites & Hardware Requirements

Official Minimum Requirements (Server Edition)

What You’ll Need Before Starting

• Ubuntu Server 26.04 LTS ISO (ubuntu-26.04-live-server-amd64.iso)
• A USB drive (8 GB or larger) or BMC/iDRAC/iLO virtual media access
• The server’s IP / gateway / DNS info if you’ll use static addressing
• SSH public key (optional but highly recommended — set it up during install)
• If using LVM/ZFS encryption: note your TPM state or prepare a passphrase

04 Download & Verify the ISO

Download from the official Canonical server

# AMD64 (most common)
wget https://releases.ubuntu.com/26.04/ubuntu-26.04-live-server-amd64.iso

# ARM64 (Raspberry Pi 5, Ampere, AWS Graviton, etc.)
wget https://releases.ubuntu.com/26.04/ubuntu-26.04-live-server-arm64.iso

Verify the download integrity (critical for production servers)

# Download the SHA256 checksum file
wget https://releases.ubuntu.com/26.04/SHA256SUMS
wget https://releases.ubuntu.com/26.04/SHA256SUMS.gpg

# Import Canonical's signing key
gpg --keyid-format long --keyserver hkps://keyserver.ubuntu.com \
    --recv-keys 0x843938DF228D22F7B3742BC0D94AA3F0EFE21092

# Verify the SHA256SUMS file signature
gpg --verify SHA256SUMS.gpg SHA256SUMS

# Verify the ISO checksum
sha256sum -c SHA256SUMS 2>&1 | grep ubuntu-26.04-live-server-amd64.iso
# Expected: ubuntu-26.04-live-server-amd64.iso: OK

Flash to USB (Linux/macOS)

# Find your USB device first
lsblk

# Flash — replace /dev/sdX with your USB device (e.g., /dev/sdb)
sudo dd if=ubuntu-26.04-live-server-amd64.iso of=/dev/sdX bs=4M status=progress oflag=sync

05 Step-by-Step Server Installation

The Ubuntu Server installer is a curses-based TUI called Subiquity. It is keyboard-driven, straightforward, and supports both interactive and autoinstall modes for unattended deployments.

Step 1 — Boot from installation media

Set your server’s boot order to boot from USB/virtual media first. Modern UEFI systems: hit F11, F12, or Del at POST to enter the boot menu. Select the Ubuntu installer media. When the GRUB menu appears, press Enter to select Install Ubuntu Server.

Step 2 — Language and keyboard

Use arrow keys to select your preferred language and keyboard layout. For most server deployments, English and the default detected layout are fine. Press Done.

Step 3 — Choose installation type

• Ubuntu Server — full server with cloud-init and common utilities (recommended)
• Ubuntu Server (minimized) — stripped-down image for containers and cloud instances

Step 4 — Network configuration

Subiquity will auto-detect your NICs and attempt DHCP. For production servers, configure a static IP:

Step 7 — Storage configuration (most important step)

Step 8 — Profile setup (user account)

# Fill in the installer form fields:
Your name:         admin               # Display name
Server's name:     prod-web-01          # Hostname (lowercase, no spaces)
Username:          ubuntu               # Avoid 'root' — use sudo instead
Password:          ••••••••••••          # Use a strong passphrase

Step 10 — SSH setup

Enable OpenSSH server during install. You can import your SSH public key directly from GitHub — the installer fetches it by your GitHub username automatically.

Step 12 — Installation and reboot

The installer copies files and configures GRUB. This typically takes 5–15 minutes. When done, remove the installation media and press Reboot Now.

06 Post-Install Checklist

Update all packages

sudo apt update && sudo apt upgrade -y
sudo apt autoremove -y
sudo reboot   # Reboot to apply any new kernel

Set timezone and NTP

sudo timedatectl set-timezone UTC
timedatectl status
# System clock synchronized: yes

Enable automatic security updates

sudo apt install unattended-upgrades -y
sudo dpkg-reconfigure --priority=low unattended-upgrades

Install essential utilities

sudo apt install -y \
    curl wget git vim htop tmux tree \
    net-tools dnsutils tcpdump \
    build-essential python3-pip \
    jq rsync lsof strace

Verify system info

lsb_release -a
Description: Ubuntu 26.04 LTS

uname -r
7.0.0-1001-generic

07 Security Hardening

Configure UFW firewall

sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow 22/tcp   # SSH — do this BEFORE enabling!
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
sudo ufw enable
sudo ufw status verbose

Harden SSH configuration

sudo nano /etc/ssh/sshd_config

PermitRootLogin no
PasswordAuthentication no
PubkeyAuthentication yes
MaxAuthTries 3
X11Forwarding no
ClientAliveInterval 300
ClientAliveCountMax 2

sudo systemctl restart sshd

Install Fail2ban

sudo apt install fail2ban -y
sudo cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

# Add to [sshd] section in jail.local:
enabled  = true
maxretry = 3
bantime  = 3600
findtime = 600

sudo systemctl enable --now fail2ban

08 Installing Popular Server Stacks

LEMP stack (Nginx + MariaDB + PHP 8.5)

sudo apt install nginx -y
sudo apt install mariadb-server -y && sudo mysql_secure_installation
sudo apt install php8.5-fpm php8.5-mysql php8.5-curl php8.5-xml php8.5-mbstring -y

PostgreSQL 18

sudo apt install postgresql postgresql-contrib -y
sudo systemctl enable --now postgresql
PostgreSQL 18.x ...

Docker 29

curl -fsSL https://get.docker.com | sudo sh
sudo usermod -aG docker $USER
docker run hello-world

NVIDIA CUDA (GPU servers)

sudo apt install nvidia-cuda-toolkit -y
nvidia-smi
CUDA Version: 12.x

09 Upgrading from Ubuntu 24.04 LTS

# Step 1: Fully update 24.04 first
sudo apt update && sudo apt dist-upgrade -y && sudo reboot

# Step 2: Run upgrade inside tmux (survives SSH disconnects)
tmux new -s upgrade
sudo do-release-upgrade

# Step 3: Reboot and verify
uname -r
7.0.0-1001-generic

Verify after upgrading

• Check for failed services: sudo systemctl –failed
• Validate cgroup v2 workloads: systemd-cgls
• Check media paths: /media → now /run/media
• AppArmor denials: sudo aa-status

10 FAQ & Troubleshooting

Q: My containers broke after upgrading — “cgroup” errors

Kernel 7.0 removes cgroup v1 entirely. Update to Docker 25+ (26.04 ships 29), JDK 11+, and replace /sys/fs/cgroup/memory/ paths with the unified /sys/fs/cgroup/.

Q: sudo behaves differently / sudo-rs issues

sudo --version   # Should show sudo-rs 0.2.x
# Need legacy sudo?
sudo apt install sudo.ws -y

Q: My server has only 2 GB RAM — will 26.04 work?

Yes. The official minimum for Ubuntu Server 26.04 is 1.5 GB RAM. 2 GB is workable for light workloads. For databases or moderate traffic, aim for at least 4 GB.

Q: How do I attach Ubuntu Pro after installation?

sudo pro attach <YOUR-TOKEN>
sudo pro status
sudo pro enable livepatch   # No-reboot kernel patching

Q: External drives not showing up in /media anymore

Kernel 7.0 changed mount points from /media/username/ to /run/media/username/. Update your scripts, backup cron jobs, and monitoring accordingly.

Q: Can I install 26.04 on IBM Z / mainframe z14?

No. Ubuntu 26.04 requires z15 (LinuxONE III) as the minimum on IBM Z. The z14 and older are not supported — stay on 22.04 or 24.04 LTS on those systems.

— References & Further Reading

• Ubuntu 26.04 LTS Official Release Notes — Canonical
• Ubuntu Server Documentation — Canonical
• Ubuntu Release Cycle & Support Windows — Canonical
• Ubuntu Pro — Extended Security Maintenance — Canonical
• Summary of Changes for LTS Users (24.04 → 26.04) — Canonical
• Community System Requirements Wiki — Ubuntu Community