Upgrading Debian 10 to Debian 11

Follow the upgrade path, don't FORGET to make the ULTIMATE backup of your system...

Upgrading Debian 10 to Debian 11

// Check the current version of your system
lsb_release -a

No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 10 (buster)
Release: 10
Codename: buster

// Check the LINUX kernel version
uname -mrs

// Answer
Linux 5.10.0-0.bpo.8-amd64 x86_64

// Check the Debian version
cat /etc/debian_version

// Answer

// Perform the last Debian 10 update before upgrading to Debian 11

sudo apt update
sudo apt upgrade
sudo apt full-upgrade
sudo apt autoremove --purge

//Boot the system to take into account the latest LINUX kernel and updates
sudo systemctl reboot

// THEN update the repositories
nano /etc/apt/sources.list

# Debian bullseye, dépôt principal + paquets non libres
deb bullseye main contrib non-free
deb-src bullseye main contrib non-free

# Debian bullseye, mises à jour "volatiles" + paquets non libres
deb bullseye-updates main contrib non-free
deb-src bullseye-updates main contrib non-free

# Debian bullseye, mises à jour de sécurité + paquets non libres
deb bullseye-security main contrib non-free
deb-src bullseye-security main contrib non-free

deb bullseye-backports main contrib non-free