How to Upgrade Debian 10 Buster to Debian 11 Bullseye

The new upcoming release of Debian 11 codenamed Bullseye is scheduled to be released on August 14, 2021. The upgrade that has been in testing for the past few years brings updates to many well-known packages such as LibreOffice being upgraded to version 7.0, GNUcash being upgraded to 4.4, and new driverless scanning and printing amongst a range of many new features.

Debian 11 supports the following Architectures:

  • 32-bit PC (i386) and 64-bit PC (amd64)
  • 64-bit ARM (arm64)
  • ARM EABI (armel)
  • ARMv7 (EABI hard-float ABI, armhf)
  • little-endian MIPS (mipsel)
  • 64-bit little-endian MIPS (mips64el)
  • 64-bit little-endian PowerPC (ppc64el)
  • IBM System z (s390x)

In the following tutorial, you will learn how to upgrade Debian 10 Buster to Debian 11 successfully.



  • Recommended OS: Debian 10 Buster
  • User account: A user account with sudo or root access.
  • Required: Internet Connection

Before upgrading your Debian 10 Buster operating system, it is a good idea to make sure it is up to date with the following terminal command:

sudo apt update && sudo apt upgrade -y

Before you go further, use the CAT command to see the version of Debian you have currently:

cat /etc/os-release

Example output:

how to upgrade debian 10 buster to debian 11 bullseye

Note, you can use the same command after the full upgrade to Bullseye to verify the update.

Before moving to the next part of the tutorial, make sure you have access to the su command (root).

To login to root use the following command:


Update Debian Buster Repo with Bullseye

Next is to update the Debian 10 Buster repository with Debian 11 Bullseye repository to download and receive the update. This is very straightforward.

First, open up using nano text editor the (sources.list) configuration file:

sudo nano /etc/apt/sources.list

Now you need to comment out all the existing entries for Debian Buster, and this is done by adding (#) at the start of each line like the example below:

how to upgrade debian 10 buster to debian 11 bullseye

Now that you have commented out the (deb HTTP) and (deb-src) Debian Buster repositories, add at the end of the file the following lines to add Debian 11 Bulleye repository as follows:

deb bullseye main
deb-src bullseye main

deb bullseye-security main
deb-src bullseye-security main

deb bullseye-updates main
deb-src bullseye-updates main

deb bullseye-backports main

Example below:

how to upgrade debian 10 buster to debian 11 bullseye

To save the files in nano text edit, press the combination on your keyboard (CTRL+O) to save (CTRL+X) to exit the text editor.

Note, if you want to enable the experimental branch to install the newest packages from upstream, add the following line to your sources.list file above:

deb experimental main

This will not interfere with your normal Debian 11 upgrade, and it is for future reference if you want to install things like the new Gnome 40 desktop, etc.

This is 100% optional and should only be added if you intend to use the feature.


Upgrade to Debian 11 with terminal command

The next step is to update your repository list to reflect the new changes and then to run the full command (full-upgrade) terminal command to begin the upgrade process as follows:

sudo apt update && sudo apt full-upgrade

Example output:

how to upgrade debian 10 buster to debian 11 bullseye

Type (Y) to proceed with the installation.

During the installation, you will encounter a pop-up with (apt-list) changes. To proceed and exit this screen, type (Q):

how to upgrade debian 10 buster to debian 11 bullseye

Next, another pop-up will ask if you would like to restart the services during the upgrade process. The default answer is no. However, it would be best if you selected yes. Choose your operation and press the ENTER key to continue:

how to upgrade debian 10 buster to debian 11 bullseye

You will need to make sure the screen doesn’t get locked or into sleep mode during the upgrade process. Also, make up any essential files you cannot afford to lose.

The upgrade process should take 5 to 10 minutes, depending on the system hardware and internet connection.

Once complete, it is advised to reboot your Debian system as most of the new changes require this to take effect. Type the following terminal command to achieve this:

sudo reboot

Confirm Debian 11 Bullseye Upgrade

Now that the upgrade process is complete, a good idea would be to check with the CAT command again as per the start of the tutorial to see the Debian operating version and build as follows:

cat /etc/os-release

Example output confirming the upgrade:

how to upgrade debian 10 buster to debian 11 bullseye

Cleaning up Debian 10 Obsolete Packages

The good idea is to clean your Debian 11 system by removing old obsolete packages that are now leftover from your successful upgrade and are not needed anymore.

how to upgrade debian 10 buster to debian 11 bullseye

You will do this with the (autoremove) command as follows:

sudo apt --purge autoremove


Nvidia Drivers

Some reports have emerged of users encountering upgrade troubles with Nvidia drivers. It is now advised to remove these as follows:

sudo apt remove *nvidia*

Comments and Conclusion

In the tutorial, you have successfully learned how to upgrade your Debian 10 Buster operating system to Debian 11 Bullseye. As mentioned at the start of the guide, Bullseye is officially not out as stable yet but will be in August.

Overall, the new Debian Bullseye has a huge range of upgrades given a long time between Debian stable being 2 years standard. You will notice many new features and upgrades to many packages.

Unlike other Linux Distributions, Debian classes itself as stability over everything, so it is definitely worth the time to do. You should not encounter too many bugs even with the release being new, as it’s been in testing for quite an extensive amount of time.

Check out more features and what’s new in Debian 11 Bullseye, and check out the official Debian release highlights.

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