Meaning to reduce the installation to a simple test install. Backgroud: at the time of Debin 8 or 9 a customer of me insisted to install the base server for ISPconfig himself. Against my adwise he did not a text install but a full install with gnome and all utilities. In case of lack of time I did not a reinstall in text mode without and Gnome. In the meantime the system at Debian 12 now, running fine with the current ISPconfig. But the updates need longer and long time from release to release. I wont to get rid of that never used stuff and to have only a minimal installation, only with the ISPconfig needed stuff. The server itself runs only as a mail relay and OPEN VPN endpoint, central router and dns server.
Try removing the desktop environment and Gnome packages. Hard part is finding names of packages. Try for example Code: dpkg --list | grep -i gnome and Code: dpkg --list | grep -i desktop If you find promising package names, for example task-desktop, read the description: Code: apt show task-desktop Then remove it with Code: apt remove task-desktop Then use Code: apt autoremove to uninstall packages that were autoinstalled just because some packages that were commanded to be installed depended on them. Then start again at the dpkg --list -command, until you have managed to remove enough. If you see you have removed something that you need, install it back with apt install, the configuration files are still there so package should work as before. You can read in file /var/log/dpkg.log what packages got removed. You can get rid of lurking configuration files from removed packages, commands to do so can be found in Debian Release Notes chapter 4.7, "Purging removed packages".
