Accelerating AIX: Performance Tuning for Programmers and System Administrators
Rudy Chukran · 1998
From the Book: This book is intended for computer professionals who need to understand and control the factors that affect performance of their AIX compatible system. I learned the techniques and system background as a result of helping customers solve performance problems on their own systems for their own environments. The material in this book is an outgrowth of AIX performance tuning seminars presented at conferences and at customer sites. You will likewise learn these methods of performance problem solving: which commands are easiest, which are most informative, which data is important and which is not, to stop tuning, and you don't even have sufficient data to tackle the problem. 0.1 Who should buy this book This is an intermediate book on AIX performance analysis for system administrators and programmers. AIX is a UNIX derivative. Previous experience with UNIX tasks such as editing files, manipulating files and directories, and shell programming is assumed. System administrators will find chapters 1, 2, 3, 4, 5, and 8 most useful. Programmers will find chapters 1, 2, 3, 6, 7, and 8 most useful. If you already have a firm basis in UNIX performance analysis, you can easily skip chapter 1. Except for reading the material in chapter 3, you can skip chapters and jump right to the topics that interest you most. 0.2 Chapter Summaries Chapter 1 is a basic overview of the concepts of performance analysis. This chapter discusses a general methodology that applies to any computer system. Chapter 2 is a brief tutorial of the design of the AIX operating system. Design concepts such as virtual memory management, filesystems, and scheduling are covered. Emphasis is on the parts of the AIX design that offer some degree of tuning. Chapter 3 covers the more rudimentary performance monitoring tools and techniques that perform the most crucial part of performance problem isolation. These tools allow you to determine whether it's the system or the application program that needs tuning. Programmers and administrators can both benefit from chapter 2. Chapter 4 covers remedies involving CPU, disk I/O and memory bottlenecks. The emphasis in this chapter is on remedies that a system administrator would make to the system configuration, such as disk configurations and virtual memory settings. Chapter 5 covers remedies involving local area networking bottlenecks. The emphasis is on network settings for TCP/IP and NFS that a system administrator would perform. Chapter 6 covers performance tools that apply primarily to application program tuning. Programming tools such as compilers, linkers, and profilers are discussed. The emphasis is on compiler flags and techniques for implementing shared libraries. Chapter 7 covers AIX system call programming. The emphasis in this chapter is on programming interfaces for interprocess communications and shared memory. Chapter 8 is a summary of the entire book. This is the chapter where the commands and techniques are reviewed for applicability. This is the what do I use when chapter. 0.3 Which Systems are Covered? AIX runs on several hardware platforms. IBM sells the RS/6000 line of products that use the PowerPC chip in their systems. Motorola sells the Power Stack line of systems. Bull sells the Escala and Estrella lines of systems. Apple sells the Network Server line of systems. All of these require the AIX version 4.1 or AIX Version 4.2 operating system. The techniques in this book apply to all these systems and both versions of AIX. At the time of writing, AIX 4.2.1 was the most current version of the operating system. This material in this book works on AIX 4.1 and AIX 4.2 system levels. AIX Version 3.2 is not specifically covered in this book; however, a great many of the techniques covered in this book also apply to AIX 3.2. Since AIX 3.2 is no longer serviced or sold, obtaining performance software for these systems is difficult. Also, the percentage of systems running AIX 3.2 should diminish to obscurity by the time you read this book. 0.4 About the Author I started in the computer industry in 1972 assembly programming on IBM mainframes. Fast forward through several years of languages, operating systems, and commercial products with IBM to 1983. That was the birth year of AIX in Austin, Texas. I, like lots of my colleagues screamed Eunuchs! Isn't that who's entrusted to guard the harem? After an initial culture shock, I learned to like UNIX and AIX. I liked it so much I spent 4 years as a kernel developer. In 1987, I left the coding tablet behind to work with customers and IBM sales people who didn't know how to spell AIX, let alone how to use and sell it. These past 10 years have been spent consulting and teaching customers about AIX. A lot of that consultation has been about performance topics. On a number of occasions the effort results in a sales win or an appreciative word about the helpful information. I usually learn something new on every encounter with customers. I learned a lot in the process of writing this book. Hopefully, you will be able to walk away with a lot of that information you're done. I welcome any constructive criticisms about this book. Send email to [email protected]