Book Image

Red Hat Enterprise Linux Troubleshooting Guide

By : Benjamin Cane
Book Image

Red Hat Enterprise Linux Troubleshooting Guide

By: Benjamin Cane

Overview of this book

Red Hat Enterprise Linux is an operating system that allows you to modernize your infrastructure, boost efficiency through virtualization, and finally prepare your data center for an open, hybrid cloud IT architecture. It provides the stability to take on today's challenges and the flexibility to adapt to tomorrow's demands. In this book, you begin with simple troubleshooting best practices and get an overview of the Linux commands used for troubleshooting. The book will cover the troubleshooting methods for web applications and services such as Apache and MySQL. Then, you will learn to identify system performance bottlenecks and troubleshoot network issues; all while learning about vital troubleshooting steps such as understanding the problem statement, establishing a hypothesis, and understanding trial, error, and documentation. Next, the book will show you how to capture and analyze network traffic, use advanced system troubleshooting tools such as strace, tcpdump & dmesg, and discover common issues with system defaults. Finally, the book will take you through a detailed root cause analysis of an unexpected reboot where you will learn to recover a downed system.
Table of Contents (19 chapters)
Red Hat Enterprise Linux Troubleshooting Guide
About the Author
About the Reviewers

Styles of troubleshooting

Before covering the best practices of troubleshooting, it is important to understand the different styles of troubleshooting. In my experience, I have found that people tend to use one of three styles of troubleshooting, which are as follows:

  • The Data Collector

  • The Educated Guesser

  • The Adaptor

Each of these styles have their own strengths and weaknesses. Let's have a look at the characteristics of these styles.

The Data Collector

I like to call the first style of troubleshooting, the Data Collector. The Data Collector is someone who generally utilizes a systematic approach to solve issues. The systematic troubleshooting approach is generally characterized as follows:

  • Asking specific questions to parties reporting issues, expecting detailed answers

  • Running commands to identify system performance for most issues

  • Running through a predefined set of troubleshooting steps before stepping into action

The strength of this style is that it is effective, no matter what level of engineer or administrator is using it. By going through issues systematically, collecting each data point, and understanding the results before executing any resolution, the Data Collector is able to resolve issues that they might not necessarily be familiar with.

The weakness of this style is that the data collection is not usually the fastest method to resolve issues. Depending on the issue, collecting data can take a long time and some of that data might not be necessary to find the resolution.

The Educated Guesser

I like to call the second style of troubleshooting, the Educated Guesser. The Educated Guesser is someone who generally utilizes an intuitive approach to solve issues. The intuitive approach is generally characterized by the following:

  • Identifying the cause of issues with minimal information

  • Running a few commands before resolving the issue

  • Utilizing previous experience to identify root cause

The strength of this style of troubleshooting is that it allows you to come up with resolutions sooner. When confronted with an issue, this type of troubleshooter tends to pull from experience and requires minimal information to find a resolution.

The weakness of this style is that it relies heavily on experience, and thus requires time before being effective. When focusing on resolution, this troubleshooter might also attempt multiple actions to resolve the issue, which can make it seem like the Educated Guesser does not fully understand the issue at hand.

The Adaptor

There is a third and often-overlooked style of troubleshooting; this style utilizes both the systematic and intuitive styles. I like to call this style the Adaptor. The Adaptor has a personality which enables it to switch between systematic and intuitive troubleshooting styles. This combined style is often faster than the Data Collector style and is more detail oriented than the Educated Guesser style. This is because they are able to apply the troubleshooting style appropriate for the task at hand.

Choosing the appropriate style

While it is easy to say that one method is better than the other, the fact of the matter is that picking the appropriate troubleshooting style depends greatly on the person. It is important to understand which troubleshooting style best fits your own personality. By understanding which style fits you better, you can learn and use techniques that fit that style. You can also learn and adopt techniques from other styles to apply troubleshooting steps that you would normally overlook.

This book will show both the Data Collector and Educated Guesser styles of troubleshooting, and periodically highlighting which personality style the steps best fit.