I find myself on a regular basis looking for various debconf variables to set before installing packages on Ubuntu. This is typically to not have to type in the answers on the various configuration screens or because I want to script an install of some package. If the package has never been installed before on that specific server then the debconf variables will not display. You can always login to another server where the package is installed to see the variables but I am going to start posting information for common packages here so others can easily find them when searching.
While working on a server farm for a client I kept running into some issues with one of the servers. The issue appeared to be a single CentOS Linux server in a cluster of ten CentOS Linux servers configured exactly the same as the other nine CentOS Linux servers was having issues writing to a network storage device. Initially I figured that the CentOS Linux server having the issues had some permission issues with the directory that was mounted to the SAN (Storage Area Network) however after minimal troubleshooting it was verified that the permissions were identical to the other servers. I started looking through other logs on the server having the issue and located some SELinux errors that were noticeably related to the issue at hand. Below I describe where the SELinux error was located, what the specific errors were, and how I was able to resolve the errors on this specific CentOS Linux server.