Upgrdae debian 12 to debian 13

To safely upgrade your Debian 12 (Bookworm) system to Debian 13 (Trixie), follow this straightforward, step-by-step terminal process. Always back up important data and configuration files before beginning. [1, 2, 3, 4]

Step 1: Update your current system

Before changing repositories, ensure your Debian 12 installation is fully up to date by running the following commands in your terminal: 

sudo apt update && sudo apt upgrade -y

Step 2: Edit your APT sources list

Open the /etc/apt/sources.list file with your preferred text editor (e.g., nano):

sudo nano /etc/apt/sources.list

Find every instance of bookworm and replace it with trixie. [1]
Save the file and exit (in Nano, press Ctrl+O, Enter, then Ctrl+X). [1]
(Note: If you have third-party or backports repositories in /etc/apt/sources.list.d/, ensure you update those files to trixie as well.)

Step 3: Refresh the package index

Update your package list to fetch the new Debian 13 repositories:

sudo apt update

Step 4: Perform the minimal upgrade

First, perform a minimal system upgrade to ensure core packages are updated without causing conflicts with new dependencies:

sudo apt upgrade -y

Step 5: Execute the full distribution upgrade

Now, run the full system upgrade to transition to Debian 13. This process will download and install the new OS packages.

sudo apt full-upgrade -y

(Note: During the upgrade, you may be prompted to keep or replace existing configuration files. In most cases, it is safest to press N to keep your current version.) [1]

Step 6: Clean up and reboot

Once the upgrade is complete, remove old, obsolete packages that are no longer supported:

sudo apt --purge autoremove -y && sudo apt autoclean -y

Finally, reboot your system so it loads into the new Debian 13 kernel and applies all changes:

sudo reboot

Upon rebooting, you can verify your new system version by running cat /etc/debian_version in your terminal. [1]