What LTS means and why it matters for servers

LTS stands for long-term support. An LTS release is a version of an operating system or app that receives security fixes for years, not months. For a server that needs to stay stable and safe, that makes LTS the default choice. This guide explains how LTS works, what end-of-life means, and how to plan around it.

Before you start

This guide uses Ubuntu as the main example, because its LTS model is the best known. The same ideas apply to Debian, AlmaLinux, Rocky Linux and to software such as Node.js and PHP.

Regular releases vs LTS

Many projects publish two kinds of release:

• Regular (interim) releases arrive often and carry the newest features. They are supported for a short time, so you must upgrade frequently.
• LTS releases arrive less often and are supported for years. Changes after release are mostly security and bug fixes, not new features.

Ubuntu, for example, publishes an LTS release every two years in April, numbered by year and month: 22.04, 24.04 and so on. Interim releases in between are supported for only about nine months.

What "support" means

During the support period, the maintainers:

• Publish security updates for known vulnerabilities.
• Fix important bugs.
• Keep package repositories available.

You still have to install those updates. Support means fixes are available, not that they are applied for you.

For Ubuntu LTS, standard security maintenance runs for about five years. Canonical's Ubuntu Pro subscription extends coverage further and adds updates for a wider set of packages. Check Canonical's current release cycle page for exact dates and terms.

Other distros differ:

• Debian stable releases get regular security support, then extra years through the Debian LTS project.
• AlmaLinux and Rocky Linux major versions follow Red Hat Enterprise Linux with a lifecycle of around ten years.

What end-of-life means

When a release reaches end-of-life (EOL), maintainers stop publishing updates for it. The server keeps running, but:

• New security holes are never fixed.
• Package repositories may move or disappear, so installing software becomes harder.
• Newer versions of apps such as PHP, Node.js or control panels stop supporting it.

Running an EOL operating system on a server reachable from the internet is a real security risk.

Why servers use LTS

• Stability: fewer big changes means fewer surprises after updates.
• Time: you upgrade the whole OS every few years instead of every few months.
• Compatibility: app vendors and control panels usually support LTS releases first.
• Documentation: most tutorials target LTS versions.

Plan your upgrades

1. Note your release's end of standard support when you set up the server.
2. About a year before that date, plan the move to the next LTS.
3. Either upgrade in place, or build a fresh server on the new release and migrate your data. A fresh build is often cleaner.
4. Take a full backup before any release upgrade.

Check it works

See which release your server runs:

lsb_release -a

On AlmaLinux or Rocky Linux, or if lsb_release is not installed:

cat /etc/os-release

On Ubuntu, the ubuntu-security-status command summarises how many installed packages receive security updates.

Troubleshooting

• apt update shows 404 errors for your release: it is past end-of-life and its repositories moved. Plan an upgrade or rebuild now.
• An app says your OS is too old: check its supported list and move to a newer LTS.
• "New release available" messages: Ubuntu offers upgrades to the next LTS once it is ready. You do not have to upgrade straight away, but plan to before support ends.
• Unsure which release to choose for a new server: pick the newest LTS that your software supports.

Next steps

• Choose your distro: which Linux distribution to choose.
• Plan the big step: release upgrade checklist.
• Keep patches flowing: automatic security updates on Linux.