Book excerpt: This is the most complete book available on performance optimization--featuring coverage of UNIX, networking (TCP/IP), hardware architecture, and program optimization--all in one volume. Covers performance basics; understanding UNIX; BSD instrumentation; System V instrumentation; system tuning; optimizing user programs written in high-level languages; and making accurate measurements. Explains in detail the output from each command--along with "real-life" rules of thumb on what value is "good" and what is not. For System Administrators, application programmers, MIS managers, and general users of UNIX systems who are interested in learning about and/or optimizing the performance of their UNIX system and networks.