The Ubuntu LTS upgrade policy intentionally delays notification of new LTS releases until after the first point release (usually ~3 months post-launch). This conservative approach ensures stability but frustrates developers needing immediate access to newer toolchains.

# Check current Ubuntu version
lsb_release -a
# Expected output for 16.04 LTS:
# Distributor ID: Ubuntu
# Description:    Ubuntu 16.04 LTS
# Release:        16.04
# Codename:       xenial

Three reliable approaches exist for forcing an early LTS-to-LTS upgrade:

Method 1: Using -d Flag with do-release-upgrade

sudo apt update
sudo apt install update-manager-core
sudo do-release-upgrade -d

The -d flag forces detection of development releases. For 16.04 → 18.04 transitions, this worked immediately after 18.04's official launch despite the point release delay.

Method 2: Manual Sources.list Modification

# Backup current sources
sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak

# Replace all instances of current release codename
sudo sed -i 's/xenial/bionic/g' /etc/apt/sources.list

# Perform upgrade
sudo apt update
sudo apt dist-upgrade
sudo do-release-upgrade

Method 3: Using update-manager CLI

sudo update-manager -c -d

After forced upgrades, perform these sanity checks:

# Verify successful upgrade
cat /etc/os-release

# Reinstall potentially broken packages
sudo apt --fix-broken install

# Clean obsolete packages
sudo apt autoremove

For developers needing specific newer packages without full LTS commitment:

# Example workflow for 16.04 → 17.10 → 18.04
sudo do-release-upgrade -d  # to 17.10
sudo do-release-upgrade -d  # to 18.04 after settling

This two-step process occasionally resolves dependency issues that direct LTS jumps might encounter.

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Ubuntu's Long Term Support (LTS) releases have a deliberate delay in upgrade notifications. The system intentionally waits until the first point release (e.g., 22.04.1) is available before prompting users about the next LTS version. This conservative approach ensures stability but can frustrate developers needing newer packages.

To force an immediate upgrade without waiting for the point release:

sudo apt update
sudo apt install update-manager-core
sudo do-release-upgrade -d

The -d flag tells the system to check for development releases, bypassing the normal LTS delay logic.

For more control, you can manually edit the release information files:

sudo nano /etc/update-manager/release-upgrades

Set these parameters:

Prompt=lts
CheckDistUpgradable=yes

For Ubuntu 20.04 → 22.04 before 22.04.1 release:

sudo sed -i 's/Prompt=never/Prompt=lts/g' /etc/update-manager/release-upgrades
sudo do-release-upgrade

After upgrade completes, verify with:

lsb_release -a
uname -a

If you encounter dependency conflicts:

sudo apt --fix-broken install
sudo dpkg --configure -a

Always create a snapshot before upgrading:

sudo timeshift --create --comments "Pre-LTS-upgrade snapshot"

For LXC containers or cloud instances:

lxc snapshot ubuntu-container pre-upgrade
aws ec2 create-image --instance-id i-1234567890 --name "pre-upgrade"