Dan Silva

xamine how to determine the root cause of Web performance problems. Without proper measurement, how do you know whether your Web application is performing well? By using open source tools such as the RRDtool, you can graph the key performance measurements of any Web application, use these graphs to determine the impact of changes in the environment, or point to changes that need addressing.

A graphical LPAR monitor for the System p5 Server that allows the status of CPU and memory resources used by one or more LPARS to be monitored side by side.

Performance metrics of a system are based purely on what is expected from it and to what extent a computer system stands up to those expectations. System performance depends on CPU, memory, disk I/O, and network. Measuring the performance of an application for its CPU usage, I/O utilization, and memory usage can greatly help in optimizing the application. It will also help in finding the performance bottlenecks. Moreover, this will improve the system performance as well as the application's performance. The case study presented in this article is intended to discuss a memory-related issue faced by one of the customers and the steps followed to pin down the root cause of the problem.

Ubuntu tips & tricks

Sametime Alarm System for Server Performance tool is a real-time system monitoring application.

GUIs are fine, but to unlock the real power of Linux®, there's no substitute for the command line. In this article, Ian Shields introduces you to some of the major features of the bash shell, with an emphasis on the features that are important for LPI certification. By the end of this article, you will be comfortable using basic Linux commands like echo and exit, setting environment variables, and gathering system information

This free tutorial will show you how to compile, install, and configure oops, an open source, high-performance, multi-threaded Web proxy under Linux. Caching Web proxies are especially useful for accelerating Web browsing performance while at the same time conserving your network bandwidth.

This tutorial reviews the origins of TCP/IP and how it works — including IP addresses, subnets, and routing. With this theoretical foundation laid, we discuss the various network configuration files required by Linux, how to initialize a network interface, and how to edit the system's routing table. The tutorial closes with a brief look at how to analyze your network and ensure that data gets to where it's supposed to go, without error.

This tutorial details the ins and outs of transforming a stock, "out of the box" Red Hat installation into a finely tuned, stable system customized to individual needs and tastes. The material presented here is based on Red Hat 7.3, although many of the techniques and procedures discussed are equally applicable to other mainstream Linux distributions. And while the title uses the phrase "performance tuning," you'll soon discover that performance and security often go hand in hand.

nUbuntu is a Linux distribution based on the popular distribution Ubuntu, tailor made for security testing.

Although GNU/Linux® has the reputation of being a much more secure operating system than Microsoft® Windows®, you still need to secure the Linux desktop. This tutorial takes you through the steps of installing and configuring antivirus software, creating a backup-restore plan, and making practical use of a firewall. When you finish, you'll have the knowledge and tools you need to harden your Linux desktop against most attacks and prevent illegitimate access to your computer.

Use this roadmap to find IBM developerWorks articles that will help you learn and review basic Linux tasks. And if you're also pursuing professional certification as a Linux system administrator, these articles can help you study for the Linux Professional Institute Certification (LPIC) exam 101 and exam 102. This roadmap is organized according to the 43 objectives in the 101 and 102 exams, which you are required to pass for LPI level 1 certification.

Make your systems and environment easier to use and administer by using tools, such as a Weblog, wiki, and Subversion, to record and track information and changes to your IT infrastructure

Systems administrators can use a number of programs to maintain files in a UNIX® system from the command line. In this tutorial, you'll experiment with commands, such as cd, cp, and tar, to navigate a UNIX file system from the command line and work with files and directories. The cd command changes directories, cp duplicates files or directories, and tar quickly groups files into an archive. You'll also learn how to deal with file permissions and perform simple input/output.

The vi text editor might seem counterintuitive to new users but, make no mistake, there is a good reason this 30-year old tool is still widely used by many of the best developers in the world. The vi text editor separates operations into insert mode and command mode, which gives you ultrafast access to key commands that can edit, insert, and move text in on-the-fly, user-defined segments

Discover the power of UNIX® filters. In this tutorial, you'll learn about the grep family in depth, including the syntax of regular expressions in many UNIX utilities. You'll also find out more about the stream editor, sed, as well as examine the awk pattern scanning language through examples and explanations.

Learn how to create, schedule, and manage cron jobs and how to define timetables to control job frequency, from once per minute to once per year. Additionally, learn how to limit access to cron to prevent abuse and how to use other utilities in tandem with cron to automate common maintenance tasks.