Upgrade Raspbian Stretch to Buster
These instructions are taken from the Raspberry Pi Blog.
As with all major version changes, it is my recommendation to download a new clean image and start fresh with a clean system. (Raspbian Download page)
I don’t know what changes people have made to their system, and so have no idea what may break when you move to Buster. The instructions below will likely work on your system. However, that does not guarantee that it will work on your system.
I cannot provide support (or be held responsible) for any problems that arise if you try it. You have been warned! Make a backup before even considering to attempt this…
Open a terminal or SSH window to your RPi.
In the files /etc/apt/sources.list and /etc/apt/sources.list.d/raspi.list, change every use of the word “stretch” to “buster”.
sudo nano /etc/apt/sources.list
sudo nano /etc/apt/sources.list.d/raspi.list
Then run the following command
sudo apt update && sudo apt dist-upgrade
Wait for the upgrade to complete, answering ‘yes’ to any prompt. There may also be a point at which the install pauses while a page of information is shown on the screen – hold the ‘space’ key to scroll through all of this and then hit ‘q’ to continue.
The update will take anywhere from half an hour to several hours, depending on your network speed. When it completes, reboot your Raspberry Pi.
When the Pi has rebooted, launch ‘Appearance Settings’ from the main menu, go to the ‘Defaults’ tab, and press whichever ‘Set Defaults’ button is appropriate for your screen size in order to load the new UI theme.
Buster will have installed several new applications which we do not support. To remove these, open a terminal window and run the following command.
sudo apt purge timidity lxmusic gnome-disk-utility deluge-gtk evince wicd wicd-gtk clipit usermode gucharmap gnome-system-tools pavucontrol
sudo apt autoremove
The reboot your RPi one last time to complete the upgrade process.
To check the OS version of Raspbian you are running, run this command.
And remember…. Make a new backup of your RPi once you have finished testing things out on your new upgraded OS version.