In many smaller organisations, developers often end up doing some system administration work (for obvious reasons). A lot of the time, they have great developer skills, but few system administration skills (perhaps all self-taught), and so have to learn as they go, which is fairly inefficient.

Are there canonical (or simply great) books that would help in this situation? More advanced than just using a shell (presumably a developer can do that), but not aimed at someone that hopes to spend many years doing this work.

Ideally, something fairly generic (although specific to a distribution would be OK), covering databases, networking, general maintenance, etc, not just one specific task.

For the most part, I'm interested in shell-based work (i.e. no GUI installed), although if there's something outstanding I'm missing, please point it out.

(As an analogy, replace "system administration" with C, and I'd want K&R, with C++ and I'd want Meyers' "Effective C++").