An Introduction To Backports For Keeping Debian Up To Date

What are Backports and Why Use Them

Backports in Debian refer to more recent package versions that have been rebuilt and adapted to run on an older Debian release. Using backports allows users to upgrade key software packages without having to perform a full Debian distribution upgrade.

The key benefits of using backports include:

Access to newer features and functionality without dist-upgrade
Updated drivers, kernels, and libraries
Improved hardware support on older Debian releases
Updated security patches for key software packages

By leveraging the backports repository, Debian administrators can update key packages and maintain a more up-to-date system while avoiding risks and challenges with major distribution upgrades.

Table of Contents

Determining Available Backports

The Debian backports repositories contain thousands of more recent package versions rebuilt and adapted for older Debian releases. Users can check for availability of backports in several ways:

Browsing the overall backports website which organizes available backported packages across over 60 software categories ranging from editors to programming languages to system utilities.
Searching for a specific package using the backports search instructions. This allows checking if a backport is available or being worked on.
Enabling the backports repository and using text-based tools like apt-cache to search for and show available backported packages for the current Debian release.

Adding the Backports Repository

To gain access to backports, the official Debian backports repository needs to be enabled on the current Debian system. This involves editing the /etc/apt/sources.list file to add the required deb-src and deb lines.

Below is an example showing backports lines after existing non-backports entries in sources.list:

deb http://deb.debian.org/debian buster main contrib non-free
deb-src http://deb.debian.org/debian buster main contrib non-free

deb http://deb.debian.org/debian buster-backports main contrib non-free 
deb-src http://deb.debian.org/debian buster-backports main contrib non-free

Key things to note when adding backports:

Include both deb and deb-src lines to enable access to backported source packages
Add contrib and non-free sections if needed based on use-case
Change “buster” to match the current base Debian release codename (e.g. stretch, jessie)

After editing sources.list, run apt update for the changes to take effect.

Upgrading Packages from Backports

With the backports repository enabled, users can now upgrade packages to newer versions. There are a few approaches for this:

Apt pinning preferences – Set up /etc/apt/preferences to prefer backports for certain packages or patterns using Package, Pin, and Pin-Priority fields.
Targeted package installs – Manually install certain packages from backports using apt install package/buster-backports
Full upgrade – Perform a complete system upgrade pulling all available packages from backports

The best approach depends on the use-case – for example, using pinning for upgrades focused on a few key packages like PHP versions. Full upgrade allows a easy system-wide upgrade but interacts most with existing system packages.

Potential Issues and Solutions

While backports provide many benefits, there are also some potential drawbacks and issues to be aware of:

Conflicts – Backported packages can sometimes conflict with other packages, dependencies, or configurations in the main Debian release.
Security support – Packages from backports have a shorter and separate security support window vs. the main Debian release.
Config changes – There is a small chance of configuration files being changed unexpectedly during backports upgrades.

Solutions to the above issues involve testing backports upgrades properly first, using pinning preferences where possible, checking security announcements for backported packages, and taking care to monitor and backup configurations.

Conclusion: Keeping Debian Up To Date Without Dist-Upgrades

In summary, backports provide Debian users, administrators, and developers with a powerful mechanism to keep key packages updated without requiring massive upgrades to new Debian releases.

By adding the backports repository, pinning preferences, and using tools like apt-get, users can obtain newer package versions for key software projects – allowing access to updated features, hardware support, and security patches.

While some care is required in testing and managing backports, overall the backports approach can fulfill many upgrade needs and help extend stable Debian release lifecycles.