View source for Upgrading Debian to the next major version

If you are doing this over the network (not on your desktop and not on a LOCAL virtual machine) you should consider to use "screen" for this process.
In case you lose connection during the update/upgrade the process will continue and you can just reconnect to the server and then reconnect to the screen (screen -r).


[[Debian#screen_.22press_space_or_return_to_end.22|The current screen has that nasty readme]]


==== 11 -> 12 (bullseye -> bookworm ====

 cat /etc/issue
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 apt-get -y autoremove
 shutdown -r now
 cat /etc/issue


or something shorter but with no control:
 cat /etc/issue
 apt-get update && apt-get -y upgrade && apt-get -y dist-upgrade && apt-get -y autoremove
 sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list
 export DEBIAN_FRONTEND=noninteractive
 apt-get update && apt-get -y upgrade && apt-get -y dist-upgrade && apt-get -y autoremove
 shutdown -r now
 cat /etc/issue

==== 10 -> 11 (buster -> bullseye) ====
 cat /etc/issue
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 sed -i 's/buster/bullseye/g' /etc/apt/sources.list
 sed -i 's/bullseye\/updates/bullseye-security/g' /etc/apt/sources.list
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 apt-get -y autoremove
 shutdown -r now
 cat /etc/issue

or something shorter but with less control:
 apt-get update && apt-get -y upgrade && apt-get -y dist-upgrade
 sed -i 's/buster/bullseye/g' /etc/apt/sources.list
 sed -i 's/bullseye\/updates/bullseye-security/g' /etc/apt/sources.list
 apt-get update && apt-get -y upgrade && apt-get -y dist-upgrade && apt-get -y autoremove
 shutdown -r now
 cat /etc/issue

==== 9 -> 10 (stretch -> buster) ====
 cat /etc/issue
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 sed -i 's/stretch/buster/g' /etc/apt/sources.list
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 apt-get -y autoremove
 shutdown -r now
 cat /etc/issue



==== 8 -> 9 (jessie -> stretch) ====
 cat /etc/issue
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 sed -i 's/jessie/stretch/g' /etc/apt/sources.list
 apt-get update
 apt-get upgrade
 apt-get dist-upgrade
 apt-get -y autoremove
 shutdown -r now
 cat /etc/issue