Debian is a popular version, or fork, of the Linux operating system.

Debian 10, codenamed Buster. The previous version Debian 9 Stretch is officially supported until June 2022. Debian version 10 offers a longer support period and new features, so it is highly recommended to upgrade if running Debian 9.

This quick tutorial will show you how to upgrade from Debian 9 (Stretch) to Debian 10 (Buster).



  • A system running Debian 9
  • A Debian user account with sudo privileges or root
  • Access to a cli/terminal or SSH
  • A recent backup of the system

Upgrade to Debian Version 10 Buster

Make sure to always backup your server prior to upgrading.

Step 1: Update Package Manager and Repositories

1. First, create a backup copy of the /etc/apt/sources.list file:

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak


2. Then, open the file for editing (we are using GNU nano for text editing):

sudo nano /etc/apt/sources.list


3. Change all the references in this file from Stretch to Buster. The entries should appear as follows:

deb debian buster main

deb buster-updates main

deb buster/updates main

4. Save the file using the keyboard combination Ctrl+O and Exit by pressing Ctrl+X.


Step 2: Upgrade from Debian 9 to Debian 10

1. Update the local package lists:

sudo apt-get update

2. Next, run updates on the software packages to prepare for the operating system upgrade:

sudo apt-get upgrade

3. Finally, run the distribution upgrade:

sudo apt-get dist-upgrade

4. Once the process completes, reboot the system to boot into Debian 10 Buster:

sudo reboot

Step 3: Verify Debian Upgrade

You can use the hostnamectl command to display the OS version with the command:


The Operating System field should display Debian GNU/Linux 10 (buster).

You can also look for the /etc/*version file or /etc/*release

The output should appear as:

PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION="10 (buster)"

Step 4: AutoRemove Outdated or UnNeeded Packages

After the upgrade to Debian 10, your system might have outdated packages and dependencies which are no longer necessary.

To remove outdated packages, run the --purge autoremove command:

sudo apt --purge autoremove