TABLE OF CONTENTS It does not matter how slowly you go, so long as you do not stop.
Confucius
One of the first principles that we introduced back in Chapter 2 was that problems vary in their severity and their range of effect. In this chapter, we'll discuss problems that are at the high end of both scales: system failures, which take an entire system out of commission until corrected. These problems can be divided into three principal classes:
Boot failures
System crashes
System hangs
The following sections discuss each of these kinds of failures and how to go about troubleshooting them. In some cases, the underlying problem turns out to be in another area (e.g., storage) that is discussed elsewhere in this book. In these cases, the techniques presented in this chapter should at least take you to the point of identifying the underlying problem area, at which point you can turn to the appropriate chapter.
