Update ALL existing installed packages
Before you upgrade your Debian version to 10, you must apply all security patches and pending upgrades to Debian 9 itself Hence, Type the following apt command or apt-get command:
sudo apt update sudo apt upgrade sudo apt full-upgrade sudo apt --purge autoremove
OR
sudo apt-get update sudo apt-get upgrade sudo apt-get full-upgrade sudo apt-get --purge autoremove
Reboot the Debian 9.x stretch to apply the kernel and other updates:
sudo reboot
Update /etc/apt/sources.list file
Before starting the upgrade you must reconfigure APT’s source-list files. To view current settings using the cat command:
cat /etc/apt/sources.list
Sample outputs:
deb http://cdn-aws.deb.debian.org/debian stretch main deb http://security.debian.org/debian-security stretch/updates main deb http://cdn-aws.deb.debian.org/debian stretch-updates main
The stretch indicates that we are using an older version. Hence, we must change all the references in this file from Stretch to Buster using a text editor such as vim:
vi /etc/apt/sources.list
I prefer to use sed tool, but first backup all config files using the cp command:
sudo cp -v /etc/apt/sources.list /root/ sudo cp -rv /etc/apt/sources.list.d/ /root/ sudo sed -i 's/stretch/buster/g' /etc/apt/sources.list sudo sed -i 's/stretch/buster/g' /etc/apt/sources.list.d/*
see updated file now
cat /etc/apt/sources.list
APT source-list files updated to use buster
Updating the package list
Simply run:
sudo apt update
Minimal system upgrade
A two-part process is necessary to avoid the removal of large numbers of packages that you want to keep. Therefore, first run the following:
sudo apt upgrade
Just follow on-screen instructions. During the upgrade process, you may get various questions, like “Do you want to restart the service? ” OR “keep or erase config options” and so on. For example, I got a screen as follows indicating new changes:
Press ‘q‘ to exit and further you may see additional screens
Upgrading Debain 9 to Debian 10
In addition, minimum upgrades we need to do full upgrades to finish the whole Debian 9 to Debian 10 update process. This is the main part of the upgrade. In other words, execute the following command to perform a complete upgrade of the system, installing the newest available versions of all packages, and resolving all possible dependency:
sudo apt full-upgrade
Reboot the Linux system to boot into Debian Linux 10 buster, issue:
sudo reboot
Verification
It is time to confirm the upgrade. Run:
uname -r lsb_release -a
Sample outputs:
No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 10 (buster) Release: 10 Codename: buster
Finally, clean up outdated packages using the apt command/apt-get command:
sudo apt --purge autoremove
Src: https://www.cyberciti.biz/faq/update-upgrade-debian-9-to-debian-10-buster/
