Course 612:
Red Hat Enterprise Linux Troubleshooting

(5 days)


Course Description

Linux is an extremely stable OS; yet, as with any complex system, it can have problems. The student completing this course will have the knowledge and techniques necessary to quickly find the cause or causes of the anomalous behavior and make informed decisions on how to lessen or fix the problem. After reviewing an area, the course presents typical problems and solutions for the area. Among other topics, the course covers the areas of booting, disk problems (LVM, RAID, ext family), handling kernel modules, client-side DHCP, NIS, and DNS, secure networking IPtable, and an overview of VPNs. Each section contains a workshop where students solve problems in the area. This course is taught using both RHEL 5 and RHEL 6 so that the changes made by Red Hat in moving to RHEL 6 are understood.

Learning Objectives

  • Learn and practice an approach to troubleshooting Linux systems
  • Steps necessary to make sure problems can be easily found and resolved
  • Hands-on experience with troubleshooting tools
  • Know what can be done to recover lost or deleted files
  • Know what can be done to recover a lost partition table
  • Troubleshoot LVM problems
  • Manage and troubleshoot kernel modules
  • Know how to solve the client-side network infrastructure problem
  • Learn the possible problems of NFS4 and the automounter
  • Work with VMware virtualization

Who Should Attend

Administrators responsible for troubleshooting problems on Red Hat Linux systems.

Suggested Prerequisites

This is a third course in Linux system administration. To be successful in this course, the student must have the background provided by ROI’s Course 603: Linux Workstation: Installing, Customizing, and Securing, and Course 604: Hat Linux Network Server: Installing, Setup, and Securing.

Course Outline

Unit 1: The General Troubleshooting Processes

  • Document What You Have
  • Where to Get Host Data
  • An Approach to Troubleshooting
  • Commands for Checking the Hardware
  • Commands for System Checking
  • Remote Troubleshooting

Unit 2: When the System Will Not Boot

  • Hardware BIOS Problems
  • How GRUB Works Both in RHEL 5 and RHEL 6
  • Booting from Rescue Disk
  • Booting from a liveCD

Unit 3: File System Problems

  • File System Organization
  • How Corruption Occurs
  • Preventative Measures
  • File Recovery Methods
  • MBR Recovery Methods
  • Performance Problems
  • Working with ext4

Unit 4: Multiple Disk Problems

  • RAID Overview
  • Configuring RAID
  • What Happens When a Disk Is Lost?
  • What Is Logical Volume Management (LVM)?
  • How Does LVM Interact with RAID?
  • How to Setup LVM

Unit 5: Software Problems

  • What Software Is Installed?
  • How Do I Know If the Software Has Been Modified?
  • Engineering Updating/Upgrading (Patching)
  • Permissions Problems

Unit 6: Kernel Considerations

  • Kernel Organization
  • Handling Kernel Changes
  • Linux Kernel Modules (LKM)

Unit 7: Host Networking

  • Hardware and Address Problems
  • Client-Side DHCP Problems
  • Client-Side DNS Problems
  • Reachability Problems

Unit 8: Secure Networking

  • Secure Shell Commands
  • Overview of VPNs
  • Firewalling with IPTables

Unit 9: Network Services

  • xinetd Considerations
  • Setting Up NFS4 and automounter
  • Bandwidth Problems

Unit 10: Virtualization

  • Explore Various Types of Virtualization
  • Virtualization with VMware

Unit 11: Where to find help

  • Documentation
  • General Forum Help
Please Contact Your ROI Representative to Discuss Course Tailoring!