About this Course
Troubleshooting is both an art and a science. An instinct and a technique. In Red Hat® Linux® Troubleshooting (RH242), system administrators will learn techniques for troubleshooting a Linux system and how to use the troubleshooting tools available on Red Hat Enterprise Linux. This course is a 4-day, heavily lab-oriented class designed to help the student learn or improve troubleshooting skills. Students will gain troubleshooting experience by debugging live, virtualized systems.
Audience Profile
Linux system administrators who understand how to install and configure a Red Hat Enterprise Linux system and who wish to deepen their understanding of troubleshooting on Linux
Course Content
During this course, students will cover the following:
- Introduction to troubleshooting techniques, including being prepared
- Troubleshooting hardware, including listing, testing, and analyzing devices
- Troubleshooting applications, including diagnosing performance problems and investigating application and OS interactions
- Troubleshooting disks and file systems, including LVM, LUKS, ext3/4, and unauthorized changes
- Troubleshooting the network, including configuring, testing, and diagnosing problems with basic and advanced configurations
- Security, including working effectively with (and not against) security tools like SELinux, authentication, and firewall
- Making the most of Red Hat support resources
Prerequisites
- Red Hat System Administration I and II or RHCSA Rapid Track Course
- RHCSA certification holder or equivalent experience
- Have system administration knowledge under Red Hat Enterprise Linux, including:
- Installation
- Service management (using service and chkconfig, for example)
- Basic system monitoring (using ps and top, and perhaps meminfo and the /proc file system)
- File system management (using fdisk and mkfs)
- Basic troubleshooting (including managing log files and perhaps the use of hardware probing tools, such as ethtool and lspci)
Course Outline
1. Being Proactive, Part 1
Proactively monitor log files, hardware, file systems, and system and network performance
2. Being Proactive, Part 2
Several approaches to managing configuration changes and developing a recovery plan
3. Basic Troubleshooting Techniques and Procedures
An introduction to troubleshooting methods, best practices, and tools
4. Booting Issues
Use recovery runlevels and rescue mode; work with advanced GRUB features
5. Hardware Issues
Preempting hardware failures (looking for the signs); protecting against hardware failures; redundant configurations; tools to help identify hardware failures and intermittent problems
6. File System Issues
Locate unauthorized changes; audit software; file system tuning and repair; file recovery
7. Disk Issues
Rescuing LVM volumes; maintenance of LUKS-encrypted volumes
8. Networking Issues
Manual configuration of network cards; connectivity issues; network diagnostic tools; monitor packets; tune kernel parameters; troubleshoot SAN communication
9. Application Issues
An overview of tools and techniques for troubleshooting applications; some common application problems and how to solve them
10. Security Issues
Working effectively with (and not against) security tools, including SELinux, authentication, and firewall
11. Red Hat Resources
Support options; Knowledgebase; certified training; initiating support calls; TAM support; developer support; Bugzilla; support workflow; diagnostic and information-gathering tools.