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

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

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

how to upgrade debian strech to debian buster


  • A system running Debian 9
  • A Debian user account with sudo privileges
  • Access to a command line/terminal window (CtrlAltF2)
  • A recent snapshot (backup) of the system

Upgrade to Debian Version 10 Buster

Step 1: Update Package Manager and Repositories

In some systems, the /etc/apt/sources.list will display:

deb stable main contrib

The stable designation means that your system is set to update to the latest stable release. Typically, that means it will upgrade when Debian 10 is released. Following the instructions here will let you upgrade sooner.

By default, Debian 9 refers to the repositories for Stretch.

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:

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

Debian Version 10 Buster successful install

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

You can also check for FTP download mirrors to replace the web address here.

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

Step 3: Verify Debian 10 Update

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)

The output should appear as:

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


By following the directions above, you should have successfully upgraded from Debian 9 to Debian 10.

For more information about the upgrade process, including notes and extensive documentation, please refer to the Debian release notes.

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