Chapter 8: Kernel Services and Configuration

Overview

In this chapter, you'll learn how to upgrade standard kernels as well as configure, compile, and install your own custom kernels. You'll see several different ways to customize and optimize your kernel configuration for size and functionality. Finally, you'll examine recommended techniques for configuring and installing the kernel.

You'll also discover how to manage and modify special partitions associated with RAID arrays and LVM filesystems. While it's most efficient to configure these partitions during the installation process, you may have to modify them during your exam.

In several places in this chapter, I embed a command such as 'uname -r' in the name of a directory or file. This command substitutes itself in the name of directory or file. If unsure, run it in your own system.

Inside the Exam

Managing Kernels

As a competent Linux administrator, you need to know how to install, patch, and recompile kernels. It's easy to install a new kernel from an RPM, which makes it a reasonable requirement on the RHCT and RHCE exams. Early versions of the RHCE Exam Prep guide suggested that you need to know how to recompile the Linux kernel. But that was a long process! However, as the process is now much easier, I would not be surprised to see the requirement return for RHCEs in the near future.

In addition, the current Exam Prep guide suggests that you need to know how to do the following during the Installation and Configuration portion of both exams:

• Properly update the Kernel package.

• Use /proc/sys and sysctl to modify and set kernel run-time parameters.

RAID and LVM

The Exam Prep guide also describes skills associated with configuring RAID and LVM after installation. I've included it in this chapter to match the RH300 course outline more closely. While it's easiest (and therefore best) if you can configure RAID and LVM during the installation process, it's not always possible. If you make a mistake during the installation process, you don't need to start over. The Exam Prep guide suggests that during the Troubleshooting and System Maintenance portion of the exam, RHCTs need to know how to

• Add new partitions, filesystems, and swap to existing systems.

RHCEs need to know how to

• Add, remove, and resize logical volumes. Remember, if you're taking the RHCE exam, you also need to meet all RHCT requirements.