Eric Lease Morgan answers the question “What should I know to be a good systems librarian?” and ends with this caveat
Please do not be overwhelmed. All of these things can be learned and practiced on your desktop or home computer. They lend themselves better to server-class operating systems such a Unix/Linux, but learning about these operating systems is challenging in itself and not readily applicable to librarianship. All you need is the ability to read books, the desire to learn, and the time to do it.