How to Upgrade Ubuntu Server to a New Release

To upgrade Ubuntu Server to a newer release, fully update the release you already run, then start the release upgrader with sudo do-release-upgrade. That tool handles release-specific package and configuration changes; running apt upgrade alone only updates packages within the current release. Back up the server and confirm the supported upgrade path before you begin.

1. Confirm the current release and target

Check the installed version and kernel before planning a maintenance window:

cat /etc/os-release
uname -r

Ubuntu supports upgrades between sequential LTS releases. You cannot skip an LTS release in one step; upgrade to the next supported LTS, then repeat if you need to reach a later one. New LTS upgrade offers may not appear until the first point release. Review the target release notes for known issues and release-specific guidance.

For production servers, LTS releases are generally the lower-maintenance choice: Ubuntu provides five years of standard security maintenance for an LTS release, while interim releases receive nine months of updates. An LTS installation normally stays on the LTS upgrade track. Change Prompt=lts to Prompt=normal in /etc/update-manager/release-upgrades only if you deliberately want interim releases and can upgrade more often. The -d option can expose a development release or force an upgrade before the normal LTS offer; do not use it as a routine production shortcut. See Ubuntu’s release lifecycle and release prompt guidance.

2. Prepare the server

Take a restorable backup or provider snapshot, and check that your application data and configuration are included. Read the target release notes for changes to services you depend on, schedule downtime, and keep a cloud serial console or other out-of-band access available. A server upgrade is interactive and can take a while; an SSH-only connection may be interrupted if networking or SSH packages restart.

Check free space and whether the current system needs a reboot before continuing:

df -h /
test -f /run/reboot-required

Also inspect any separate /var or /boot filesystems. Release upgrades download many packages and can require several gigabytes of free space.

Review third-party apt sources and PPAs as well. Ubuntu disables them during a release upgrade, although packages already installed from them are not automatically removed. Confirm that the software has a compatible repository for the target release before you plan to re-enable a source.

3. Fully update the current release

Refresh package metadata and install pending updates before changing Ubuntu versions:

sudo apt update
sudo apt dist-upgrade -o APT::Get::Always-Include-Phased-Updates=true

Let both commands finish successfully. Read any package removal list before accepting it, especially if it includes software your services need. If the system reports that a reboot is required, reboot and reconnect before proceeding. Do not start the release upgrade while package operations are incomplete.

4. Run the release upgrader

Start the supported server upgrade from a terminal:

sudo do-release-upgrade

Follow the prompts and keep the session attended. Before confirming, review the summary of packages to install, upgrade, or remove and the download size. Cancel and investigate if the proposed changes are unexpected. Do not close the terminal or power off the server during installation.

If the upgrader asks about a locally modified configuration file, compare the offered version with your current one. The usual default is to keep the local file, but that is not always the right choice; a setting needed for the new release may have changed. Use the prompt’s diff option where available and decide deliberately. Keep console access available in case a network or SSH configuration change affects remote access.

5. Reboot and verify services

At the end, accept the requested restart or reboot manually. The release change is not complete until the server has restarted into the new system. After reconnecting, verify the installed release and check for failed systemd units:

lsb_release -a
systemctl --failed

Then test the services your workload depends on, such as web, database, storage, or monitoring services. Check their status and logs if anything is missing or fails to start. Re-enable third-party repositories only after confirming they support the new Ubuntu release, then run sudo apt update again.

If no upgrade is offered

Make sure the current release is fully updated and that you are following a supported path. For an LTS-to-LTS upgrade, Ubuntu may wait until the first point release before enabling the offer; do not force it with -d on a production server. If your installation has reached end of life, use Ubuntu’s separate end-of-life upgrade guidance rather than changing repository URLs at random.

Official references

• Ubuntu Server release upgrade guide
• Ubuntu release notes
• Ubuntu release cycle and support lifecycle