The Red Hat Enterprise Linux 5 I/O Tuning Guide presents the basic
principles of performance analysis and tuning for the I/O
subsystem. This document also provides techniques for
troubleshooting performance issues for the I/O subsystem.
This guide describes how to analyze and appropriately tune the I/O performance of your Red Hat Enterprise Linux 5 system.
Caution
While this guide contains information that is field-tested and proven, it is recommended that you properly test everything you learn on a testing environment before you apply anything to a production environment.
In addition to this, be sure to back up all your data and pre-tuning configurations. It is also prudent to plan for an implementation reversal.
Scope
This guide discusses the following major topics:
Investigating system performance
Analyzing system performance
Red Hat Enterprise Linux 5 performance tuning
Optimizing applications for Red Hat Enterprise Linux 5
The scope of this document does not extend to the investigation and administration of faulty system components. Faulty system components account for many percieved performance issues; however, this document only discusses performance tuning for fully functional systems.
1.1. Audience
Due to the deeply technical nature of this guide, it is intended primarily for the following audiences.
Senior System Administrators
This refers to administrators who have completed the following courses / certifications:
This guide also contains several sections on how to properly tune applications to make them more resource-efficient.
1.2. Document Conventions
Certain words in this manual are represented in different fonts, styles, and weights. This highlighting indicates that the word is part of a specific category. The categories include the following:
Courier font
Courier font represents commands, file names and paths, and prompts.
When shown as below, it indicates computer output:
Desktop about.html logs paulwesterberg.png
Mail backupfiles mail reports
bold Courier font
Bold Courier font represents text that you are to type, such as: xload -scale 2
italic Courier font
Italic Courier font represents a variable, such as an installation directory: install_dir/bin/
bold font
Bold font represents application programs, a button on a graphical application interface (OK), or text found on a graphical interface.
Additionally, the manual uses different strategies to draw your attention to pieces of information. In order of how critical the information is to you, these items are marked as follows:
Note
Linux is case-sensitive: a rose is not a ROSE is not a rOsE.
Tip
The directory /usr/share/doc/ contains additional documentation for installed packages.
Important
Modifications to the DHCP configuration file take effect when you restart the DHCP daemon.
Caution
Do not perform routine tasks as root—use a regular user account unless you need to use the root account for system administration tasks.
Warning
Be careful to remove only the listed partitions. Removing other partitions could result in data loss or a corrupted system environment.
File the bug against Product: Red Hat Enterprise Linux, Version: rhel5-rc1. The Component should be Performance_Tuning_Guide.
Be as specific as possible when describing the location of any revision you feel is warranted. If you have located an error, please include the section number and some of the surrounding text so we can find it easily.
