In Place Upgrade Debian 10 Buster to 11 Bullseye

  1. Log into the Debian 10 device
  2. Run the following commands in a terminal window
    # clean apt cache
    sudo apt clean
    # update apt repositories to bullseye
    find /etc/apt -type f -name "*.list" -print0 | xargs -0 sudo sed -i.bak "s/buster\/updates/bullseye-security/g;s/buster/bullseye/g"
    # update software repositories
    sudo apt update
    # install software updates
    sudo apt dist-upgrade -y
    # clean apt cache
    sudo apt clean
    # reboot
    sudo reboot now
  3. That's it, Debian 10 Buster has been updated in place to Debian 11 Bullseye