Chapter 2: System Requirements and Installation

Updated

October 31, 2026

Chapter 2: System Requirements and Installation

Installing a modern enterprise Linux distribution requires understanding hardware capabilities, firmware security policies, and deployment modalities.

Ubuntu 26.04 LTS simplifies this across all form factors using Subiquity—Canonical’s declarative installer engineered for desktop workstations, headless bare-metal servers, automated data center PXE rollouts, and hyperscale cloud images.

This chapter walks through hardware requirements, image integrity verification, installation procedures, dual-boot setups alongside Windows BitLocker, automated autoinstall configurations, and post-installation initialization.

Hardware Minimums and Recommended Specs

Ubuntu 26.04 LTS runs across x86-64 (specifically x86-64-v2 baseline, with optional x86-64-v3 optimized repositories), 64-bit ARM (ARMv8.2-A+), RISC-V (RVA22 profile), and IBM s390x.

Resource Component	Desktop Minimum	Desktop Recommended	Server Minimal	Server Production
CPU Architecture	64-bit Dual-Core 2.0 GHz	Quad-Core 2.5 GHz+ (x86-64-v3 or ARM64)	1 vCPU (64-bit)	4+ physical cores
System Memory (RAM)	4 GB	8 GB to 16 GB+	1 GB	8 GB to 64 GB+
Storage Capacity	25 GB SSD	64 GB+ NVMe SSD	5 GB SSD	100 GB+ NVMe / RAID
Firmware / Security	UEFI 2.7+ & TPM 2.0	UEFI Secure Boot & TPM 2.0	BIOS or UEFI	UEFI Secure Boot & TPM 2.0
Graphics Adapter	1024x768 (VGA/Intel HD)	Wayland-capable GPU (Intel/AMD/NVIDIA)	Headless (Serial/SSH)	Headless (IPMI/BMC)

[!IMPORTANT] TPM 2.0 Requirement for Native FDE: To utilize Ubuntu 26.04’s automatic hardware-backed Full Disk Encryption without typing a manual unlock passphrase at every reboot, the machine must feature an operational TPM 2.0 chip enabled in UEFI firmware.

Downloading ISOs and Verifying Checksums

Never boot an unverified operating system image. To guard against download corruption and man-in-the-middle tampering, verify both the cryptographic hash and Canonical’s OpenPGP signature.

# 1. Download Ubuntu 26.04 LTS Desktop/Server ISO and verification files
wget https://releases.ubuntu.com/26.04/ubuntu-26.04-desktop-amd64.iso
wget https://releases.ubuntu.com/26.04/SHA256SUMS
wget https://releases.ubuntu.com/26.04/SHA256SUMS.gpg

# 2. Retrieve Canonical's official release signing key
gpg --keyid-format long --keyserver keyserver.ubuntu.com \
    --recv-keys "8439 38DF 228D 22F7 B374 2BC0 D94A A3F0 EFE2 1092"

# 3. Verify the GPG signature on the checksum file
gpg --verify SHA256SUMS.gpg SHA256SUMS

# 4. Verify the integrity of the downloaded ISO
sha256sum --check --ignore-missing SHA256SUMS

Expected output:

ubuntu-26.04-desktop-amd64.iso: OK

Creating Bootable Media

On Linux or macOS, write the verified ISO directly to a raw USB flash drive using dd:

# Identify your target flash drive (e.g., /dev/sdb - CAUTION: verify device node!)
lsblk

# Flash ISO to USB drive (unmount partitions first if mounted)
sudo dd if=ubuntu-26.04-desktop-amd64.iso of=/dev/sdb bs=4M status=progress conv=fsync

The Subiquity Installer Walkthrough

The Subiquity installer powers both desktop and server editions, sharing a common declarative Python/Flutter core:

┌────────────────────────────────────────────────────────────────────────┐
│                   SUBIQUITY INSTALLATION WORKFLOW                      │
│                                                                        │
│   1. Locale & Keyboard Layout Selection                                │
│   2. Network Connectivity (DHCP, Static IP, Wi-Fi, or VLAN)            │
│   3. Installation Profile (Default Minimal vs. Full Applications)      │
│   4. Storage Partitioning & Encryption:                                │
│      ├─ [Option A] Erase disk and install Ubuntu                       │
│      ├─ [Option B] TPM 2.0-backed Hardware Full Disk Encryption        │
│      ├─ [Option C] Manual LUKS2 Passphrase Encryption                  │
│      └─ [Option D] Custom Manual Storage (ZFS, LVM, Btrfs)             │
│   5. Identity Creation (Username, Hostname, Password, SSH Keys)        │
│   6. Ubuntu Pro Enrollment (Optional 1-click token attachment)         │
│   7. Background Base System Extraction & Kernel Installation           │
└────────────────────────────────────────────────────────────────────────┘

Dual-Boot Scenarios with BitLocker Windows

When installing Ubuntu 26.04 alongside an existing Windows 11 installation protected by BitLocker:

Do NOT Disable BitLocker in Windows: Older distributions required decrypting Windows partitions. Ubuntu 26.04 respects existing BitLocker partitions.
Back Up Windows BitLocker Recovery Key:
- In Windows, run: manage-bde -protectors -get C:
- Store the 48-digit recovery key in a safe offline location.
Shrink Windows C: Drive:
- In Windows Disk Management (diskmgmt.msc), shrink the volume to free at least 50 GB of unallocated space.
Subiquity Partitioning:
- Choose “Install Ubuntu alongside Windows Boot Manager”.
- Subiquity automatically creates an ext4 root partition in the unallocated space and registers an entry into the existing EFI System Partition (ESP) without overwriting the Windows bootloader.

Server Installation and Automated Autoinstall

For headless server deployments, Subiquity supports declarative YAML autoinstall directives via cloud-init, USB seeds, or PXE boot:

# autoinstall.yaml - Declarative headless provisioning
#cloud-config
autoinstall:
  version: 1
  locale: en_US.UTF-8
  keyboard:
    layout: us
  network:
    network:
      version: 2
      ethernets:
        ens192:
          dhcp4: true
  storage:
    layout:
      name: lvm
      match:
        size: largest
  identity:
    hostname: srv-u26-node01
    username: sysadmin
    password: "$6$rounds=4096$salt$encryptedpasswordhashhere..."
  ssh:
    install-server: true
    authorized-keys:
      - "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIExampleAdminKey sysadmin@ops"
    allow-pw: false
  packages:
    - htop
    - curl
    - tmux
    - ufw

To boot an automated installer:

linux /casper/vmlinuz autoinstall ds=nocloud-net;s=http://192.168.1.50/tftp/ ---
initrd /casper/initrd

Cloud Images: AWS, Azure, GCP, Oracle Cloud, and IBM Cloud

In public cloud environments, manual installation is bypassed entirely in favor of pre-baked, cloud-optimized AMIs and VHDs maintained by Canonical.

Cloud images feature: - Cloud-specific kernels (linux-aws, linux-azure, linux-gcp) compiled with proprietary virtualization drivers (e.g., AWS ENA network drivers, Azure MANA, GCP gVNIC). - Zero-delay serial console logging. - Minimal disk footprint (under 1.5 GB uncompressed base size).

Launch commands:

# AWS EC2 (Ubuntu 26.04 LTS arm64 / Graviton)
aws ec2 run-instances --image-id resolve:ssm:/aws/service/canonical/ubuntu/server/26.04/stable/current/arm64/hvm/ebs-gp3/ami-id \
    --instance-type c7g.large --key-name my-key-pair

# Azure CLI
az vm create --resource-group myRG --name u26vm --image Canonical:ubuntu-26_04-lts:server:latest --generate-ssh-keys

# Google Cloud Platform (GCP)
gcloud compute instances create u26-vm --image-family=ubuntu-2604-lts --image-project=ubuntu-os-cloud --zone=us-central1-a

Post-Install Setup

Immediately after the initial reboot, execute foundational hygiene commands:

# 1. Update package lists and apply security patches
sudo apt update && sudo apt upgrade -y

# 2. Verify active kernel and architecture
uname -mrs
# Output: Linux 6.14.0-15-generic x86_64

# 3. Check TPM 2.0 status and disk encryption
systemd-cryptenroll --tpm2-device=list

# 4. Enable UFW firewall with SSH access
sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow OpenSSH
sudo ufw enable

Chapter Summary

Ubuntu 26.04 LTS runs on x86-64, ARM64, and RISC-V with hardware-enforced security baselines.
Always verify SHA256 hashes and OpenPGP signatures before writing ISO images to storage media.
Subiquity provides a unified installer supporting interactive desktop setups, TPM 2.0 hardware encryption, and headless declarative YAML autoinstallations.
Cloud platforms offer optimized images pre-tuned for hyperscale virtualization drivers and sub-second initialization.