Upgrade Debian 11 to Debian 12

3 min readSep 27, 2023

In this article, I quickly describe the new Debian 12 release characteristics and show you how to upgrade your Debian 11.

About Debian 12…

Debian 12 is here since July 2023.

Debian 12 has been developed during 1 year, 9 months and 28 days.
Debian 12 will be supported the next 5 years.
Debian 12 supersedes Debian 11.

Debian 12 is powered by Linux kernel 6.1 which is an LTS version that includes numerous enhancements such as improved support for AMD CPUs, experimental support for Rust, and ARM SoC support among many others.

Debian 12 provides support for Pipewire out-of-the-box which replaces PulseAudio as the default audio and service.

The non-free firmware are now in a new archive area (non-free-firmware), separated from other non-free packages.

Features and updates

Debian 12 bookworm ships with several desktop environments, such as:

Gnome 43,
KDE Plasma 5.27,
LXDE 11,
LXQt 1.2.0,
MATE 1.26,
Xfce 4.18

Debian 12 bookworm includes numerous updated software packages (over 67% of all packages from the previous release), such as:

Apache 2.4.57
BIND DNS Server 9.18
Cryptsetup 2.6
Dovecot MTA 2.3.19
Emacs 28.2
Exim (default email server) 4.96
GIMP 2.10.34
GNU Compiler Collection 12.2
GnuPG 2.2.40
Inkscape 1.2.2
The GNU C Library 2.36
lighthttpd 1.4.69
LibreOffice 7.4
Linux kernel 6.1 series
LLVM/Clang toolchain 13.0.1, 14.0 (default), and 15.0.6
MariaDB 10.11
Nginx 1.22
OpenJDK 17
OpenLDAP 2.5.13
OpenSSH 9.2p1
Perl 5.36
PHP 8.2
Postfix MTA 3.7
PostgreSQL 15
Python 3, 3.11.2
Rustc 1.63
Samba 4.17
systemd 252
Vim 9.0
…

A total of nine architectures are officially supported for bookworm:

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)

The Debian Cloud team publishes bookworm for several cloud computing services:

Amazon EC2 (amd64 and arm64),
Microsoft Azure (amd64),
OpenStack (generic) (amd64, arm64, ppc64el),
GenericCloud (arm64, amd64),
NoCloud (amd64, arm64, ppc64el)

The genericcloud image should be able to run in any virtualised environment.

The Official Debian 12 Release Notes for x64 is in the following Card:

Release Notes for Debian 12 (bookworm), 64-bit PC

This document is free software; you can redistribute it and/or modify it under the terms of the GNU General Public…

www.debian.org

Upgrading Debian

Upgrades to Debian 12 bookworm from the previous release, Debian 11 bullseye, are automatically handled by the APT package management tool for most configurations.

If you want to upgrade quickly your Debian 11 to 12, you can run the following steps:

Step 1: Prepare for upgrade

# Make sure you up-to-date
sudo apt update
sudo apt upgrade
sudo apt full-upgrade
sudo apt autoremove

# reboot you system
sudo systemctl reboot
# Backup your system (replace $user by the real username)
sudo cp -v /etc/apt/sources.list /home/$user/
sudo cp -vr /etc/apt/sources.list.d/ /home/$user/

Step 2: Modify sources.list

# Edit sources.list
sudo nano /etc/apt/sources.list

# Comment old entries and add these to the sources.list
deb http://deb.debian.org/debian/ bookworm main
deb-src http://deb.debian.org/debian/ bookworm main

deb http://security.debian.org/debian-security bookworm-security main
deb-src http://security.debian.org/debian-security bookworm-security main

deb http://deb.debian.org/debian/ bookworm-updates main
deb-src http://deb.debian.org/debian/ bookworm-updates main

deb http://deb.debian.org/debian bookworm non-free non-free-firmware
deb-src http://deb.debian.org/debian bookworm non-free non-free-firmware

deb http://deb.debian.org/debian-security bookworm-security non-free non-free-firmware
deb-src http://deb.debian.org/debian-security bookworm-security non-free non-free-firmware

deb http://deb.debian.org/debian bookworm-updates non-free non-free-firmware
deb-src http://deb.debian.org/debian bookworm-updates non-free non-free-firmware

Step 3: Upgrade all

# Upgrade your system
sudo apt update
sudo apt full-upgrade

# Restart your system
sudo systemctl reboot

Step 4: Check your installation & clean

# Check current version
cat /etc/debian_version

# Clean the system
sudo apt --purge autoremove

Debian references

Official Debian 12 installation Guide:
https://www.debian.org/releases/bookworm/amd64/

Official Debian images:
https://www.debian.org/releases/bookworm/debian-installer/

Download amd64 live iso here:
https://cdimage.debian.org/debian-cd/current-live/amd64/iso-hybrid/

Here you can find the complete chapter to see the issues to be aware of for bookworm:
https://www.debian.org/releases/bookworm/amd64/release-notes/ch-information.en.html#grub-os-prober

Conclusion

I hope this article can help you upgrading your system to Debian 12.

Thanks by advance for the like :-) :-)