Red Hat Enterprise Linux troubleshooting guide : identify, capture, and resolve common issues faced by Red Hat Enterprise Linux administrators using best practices and advanced troubleshooting techniques / Benjamin Cane.

Format:

Book

Author/Creator:

Cane, Benjamin, author.

Series:

Packt enterprise.

Professional expertise distilled

Language:

English

Subjects (All):

Red Hat, Inc.

Linux.

Operating systems (Computers).

Physical Description:

1 online resource (458 p.)

Edition:

1st edition

Place of Publication:

Birmingham : Packt Publishing, 2015.

System Details:

text file

Biography/History:

Cane Benjamin: Benjamin Cane has nearly 10 years of experience in Linux systems administration. His first systems administration role was in 2006. At that time, he worked for a web hosting company supporting thousands of FreeBSD and Linux systems. Afterwards, he joined a managed services company that specialized in managing mission-critical systems. There, he worked his way to the position of a lead systems engineer, providing 24x7 support for highly critical enterprise systems that ran Red Hat Enterprise Linux. Now, Benjamin is a systems architect. He focuses on building High and Continuous Availability environments within the financial services industry. He is also currently a Red Hat Certified Engineer and Certified Ethical Hacker. With his experience in mission-critical environments, he has learned to identify and troubleshoot very complex issues quickly, because often these environments have a low tolerance for downtime. Being able to identify the root causes of very complex systems issues quickly is a skill that requires extensive knowledge of Linux and troubleshooting best practices. In addition to this book, Benjamin writes about Linux systems administration and DevOps topics on his blog at http: //bencane. com. He is also the project founder for Runbook (https: //github. com/Runbook/runbook), an open source application designed to monitor and automatically resolve infrastructure and application issues.

Summary:

Identify, capture and resolve common issues faced by Red Hat Enterprise Linux administrators using best practices and advanced troubleshooting techniques About This Book Develop a strong understanding of the base tools available within Red Hat Enterprise Linux (RHEL) and how to utilize these tools to troubleshoot and resolve real-world issues Gain hidden tips and techniques to help you quickly detect the reason for poor network/storage performance Troubleshoot your RHEL to isolate problems using this example-oriented guide full of real-world solutions Who This Book Is For If you have a basic knowledge of Linux from administration or consultant experience and wish to add to your Red Hat Enterprise Linux troubleshooting skills, then this book is ideal for you. The ability to navigate and use basic Linux commands is expected. What You Will Learn Identify issues that need rapid resolution against long term root cause analysis Discover commands for testing network connectivity such as telnet, netstat, ping, ip and curl Spot performance issues with commands such as top, ps, free, iostat, and vmstat Use tcpdump for traffic analysis Repair a degraded file system and rebuild a software raid Identify and troubleshoot hardware issues using dmesg Troubleshoot custom applications with strace and knowledge of Linux resource limitations In Detail 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 reboo...

Contents:

Cover; Copyright; Credits; About the Author; About the Reviewers; www.PacktPub.com; Table of Contents; Preface; Chapter 1: Troubleshooting Best Practices; Styles of troubleshooting; The Data Collector; The Educated Guesser; The Adaptor; Choosing the appropriate style; Troubleshooting steps; Understanding the problem statement; Asking questions; Attempting to duplicate the issue; Running investigatory commands; Establishing a hypothesis; Putting together patterns; Is this something that I've encountered before?; Trial and error; Start by creating a backup; Getting help; Books

Team Wikis or RunbooksGoogle; Man pages; Red Hat kernel docs; People; Documentation; Root cause analysis; The anatomy of a good RCA; The problem as it was reported; The actual root cause of the problem; A timeline of events and actions taken; Any key data points to validate the root cause; A plan of action to prevent the incident from reoccurring; Establishing a root cause; Sometimes you must sacrifice a root cause analysis; Understanding your environment; Summary; Chapter 2: Troubleshooting Commands and Sources of Useful Information; Finding useful information; Log files

The default locationCommon log files; Finding logs that are not in the default location; Configuration files; Default system configuration directory; Finding configuration files; The proc filesystem; Troubleshooting commands; Command-line basics; Command flags; The piping command output; Gathering general information; w - show who is logged on and what they are doing; rpm - RPM package manager; df - report file system space usage; free - display memory utilization; ps - report a snapshot of current running processes; Networking; ip - show and manipulate network settings

netstat - network statisticsPerformance; iotop - a simple top-like I/O monitor; iostat - report I/O and CPU statistics; vmstat - report virtual memory statistics; sar - collect, report, or save system activity information; Summary; Chapter 3: Troubleshooting a Web Application; A small back story; The reported issue; Data gathering; Asking questions; Duplicating the issue; Understanding the environment; Where is this blog hosted?; Ok, it's within our environment; now what?; What services are installed and running?; Looking for error messages; Apache logs; Verifying the database

Verifying the WordPress databaseEstablishing a hypothesis; Resolving the issue; Understanding database data files; Finding the MariaDB data folder; Resolving data file issues; Validating; Final validation; Summary; Chapter 4: Troubleshooting Performance Issues; Performance issues; It's slow; Performance; Application; CPU; Top - a single command to look at everything; Determining the number of CPUs available; ps - Drill down deeper on individual processes with ps; Putting it all together; A quick look with top; Memory; free - Looking at free and used memory; Checking for oomkill

ps - Checking individual processes memory utilization

Notes:

Includes index.

Description based on online resource; title from PDF title page (ebrary, viewed January 4, 2016).

ISBN:

9781785287879

1785287877

OCLC:

928751268