First of we ensure that the current installation is as upgraded as possible and that all the packages in the systems have the lastest version without showing any errors or broken packages.
apt update
apt upgrade -y
These commands will verify the package installation and show any issues with the current installation.
dpkg -C
apt-mark showhold
We need to update the sources file and change all instances of jessie to buster, this can be done manually for more control but this is the sed command to switch fast and easy which is less error prone.
sed -i 's/jessie/buster/g' /etc/apt/sources.list
Next step we can check the configuration files and that we don't have any unexpected configuration files that contain the jessie keyword.
grep -lnr jessie /etc/apt
Removing the package apt-listchanges will improve the installation speed. You may add it again after installation. The package will check the changelog between package upgrades and report the information back to you.
apt remove apt-listchanges
Now we start the upgrade, updating to the buster system and then do a full upgrade. This command will not only install the latest packages and kernel modules but remove packages if conflicting with new packages.
apt update
apt full-upgrade -y
Last we have some commands to remove old packages that are deprecated and clean up after the upgrade.
apt autoremove -y
apt autoclean
thank you . really helped out. i have memory loss