“Andregg gave a full-day seminar on the ins and outs of Linux
system administration, from the simple to the decidedly advanced.
After all, a problem that may be elementary to one person may
be hideously complex to another, only because the latter person
hasn’t yet had to deal with it, hasn’t yet had to think about it,
or never really twisted it around in a manner that makes it easy to
tackle. Andregg assumed nothing about the skill level of his
students, and in so doing was able to ease into some very complex
issues for Linux administration.”
“After putting some simple issues aside, the first thing Andregg
really dove into was the File-system Hierarchy Standard, or FHS.
The FHS is a standard directory structure that was designed in the
hopes that all Linux distributions would put their binaries,
libraries, configuration files, etc. in the same place. In this
way, installed software would always know where to find the things
it was looking for, and how to put itself into a place that would
be correct…”
“PAM was designed as an answer to a problem many administrators
have faced when converting from storing passwords in /etc/passwd to
using shadow passwords. In a PAM-less world, any application which
tries to read the password (screen locks, user maintenance
utilities, etc.) would first need to be modified to use the shadow
password and then recompiled. PAM provides a different access
method, allowing PAM modules to be installed for password files,
SecurID cards, or just about any authentication scheme you can
think of…”