Many software packages are moving to a multiple file configuration system. Debian developers are using this feature to protect local changes by instructing administrators to place their modifications in a file with a . local extension. In other cases, such as the Apache configuration directories, files are placed in specified subdirectories (conf.d and sites-available in this case), and may be named freely, as long as they don't conflict with file names used by standard Debian or upstream configurations. In these cases, the Debian developers have modified the configuration files so they contain commands to include local configuration files, overriding the standard files as necessary. In any case, a savvy administrator will use such separate files for local configuration changes when possible, so that they are unaffected by package updates.
One of the side effects of this separation of local configuration files is that the update procedure will no longer ask you whether to install the developers' configuration, leave the local configuration, or reconcile the two. Generally, this is what you want, as your local changes will remain in place, and any new features will have reasonable defaults that shouldn't cause problems. However, in cases where there are possible major changes to the configuration defaults, a pop-up description of the changes occurs during the upgrade (requiring acknowledgement), and is also emailedtotherootaccount.Evenwithoutthis.though.itis good practice to browse the package documentation for configuration advice and the configuration files for any obvious changes, after the upgrade is complete.
