UPGRADING RASPBERRY PI OS IN PLACE
Doing an in place upgrade is rather simple actually. Edit one file, execute three commands and done!
EDIT THE APT SOURCES FILE
Edit the sources.list file :
sudo nano /etc/apt/sources.list
Then change the line that should be at the top, that reads :
deb http://raspbian.raspberrypi.org/raspbian/ buster main contrib non-free rpi
And change the "buster" part, the Debian release version according to the following:
|Debian version||Code name||Release date|
|Debian 8||Jessie||September 2015|
|Debian 9||Stretch||August 2017|
|Debian 10||Buster||June 2019|
|Debian 11||Bullseye||November 2021|
As of the time of writing this, you would want to use "bullseye".
Execute the following two commands to update the system:
sudo apt update sudo apt upgrade
When the upgrade command completes, you can then do :
Once the Pi is back up and sitting at the login screen/desktop you are golden!