One of the stability requirements for Debian is that when a package is installed, it should not adversely affect the system. Often, this is as simple as providing a standard configuration, such as Apache's simple It works! page. In other cases, however, at least some information must be provided during installation in order to create a basic, working configuration. This is handled by having the installation procedure ask the necessary questions during the installation process in order to create a working configuration. Infact, Debian developers have created the extensive debconf subsystem for this purpose.
The debconf subsystem provides the ability to configure packages before, during, and after installation, and it is integrated into all Debian packages that require configuration. Itsupports a number of frontend user interfaces, prewritten answers that can be input to the installation process, a simple interface for asking questions and providing the answers to the installation scripts, and even ways to reconfigure packages any time after installation. In general, this method of configuration provides only the most commonly used configuration options. More complex configurations must be handled by using any utilities provided by the packages, or by editing the configuration files directly.
Even if you edit configuration files directly, Debian admirristrators have passed on various techniques to the developers to ease this process. In some cases, they have created alternative and more understandable configuration files that are scanned and used to create the actual, complex configuration by scripts provided in the package. A good example of this is the GRUB2 boot loader. An administrator makes whatever modifications to the configuration files in Jete/default and /ete/grub. d, and then runs update-grub to create the actual file that GRUB uses to load the operating system. The script then executes the necessary commands for creating and installing the configuration, as well as the necessary updates of other files affected by GRUB reconfiguration. This is just one example of how various utilities created by the Debian developers and other third parties have simplified Debian administration.
Another good example is sendmail. Administrators often modify the files and various database files required by sendmail to tailor it for large, corporate installations. However, instead of compiling the configuration and databases, then forcing sendmail to load the new configuration, a single command, sendmaileonfig, will perform all of the necessary steps at once, with minimal interruption in server operation.
