Book Image

Linux Utilities Cookbook

By : James Kent Lewis
Book Image

Linux Utilities Cookbook

By: James Kent Lewis

Overview of this book

<p>Linux is a stable, reliable and extremely powerful operating system. It has been around for many years, however, most people still don't know what it can do and the ways it is superior to other operating systems. Many people want to get started with Linux for greater control and security, but getting started can be time consuming and complicated. <br /><br />A practical, hands-on guide that provides you with a number of clear step-by-step examples to help you solve many of the questions that crop up when using an operating system you may not be familiar with.</p> <p>Presenting solutions to the most common Linux problems in a clear and concise way, this helpful guide starts with spicing up the terminal sessions by command retrieval and line editing, and shell prompt variables. We will then get to know the different desktops (GUIs) available for Linux systems and which is the best fit for you. We will then explore the world of managing files and directories, connectivity, and what to do when it goes wrong. We will also learn a range of skills, from creating and managing user accounts to securing your system, managing and limiting processes, and letting information flow from one process to another using pipes. Later, we will master disk management, working with scripts and automating tasks quickly, and finally, understand the need for a custom kernel and tips on how to build one.</p> <p><br />Based on the author's extensive experience, there is a section on best practices that every Linux user should be familiar with.</p>
Table of Contents (19 chapters)
Linux Utilities Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using and monitoring a UPS


In my opinion it is imperative that a UPS be used on at least your primary workstation. All kinds of bad things can happen to the hardware if the power suddenly goes off (or worse, browns out), not to mention what might happen to your data. With modern journaling filesystems, I realize data loss is somewhat rare, but why take the chance? Also, I really just don't like to reboot. Ever.

Depending on your situation, try to get the best UPS you can afford. You want one that will run your system for a long time and also power your display, modem, router, and external drives if you have them. This way, if the power goes out for just a short time you won't lose anything, and won't have to wait for everything to come back up.

There are many different UPS brands available today. I am somewhat partial to the American Power Conversion (APC) devices. I have several of them, and they work well with Linux. Be sure to get one with a phone-connector to USB port, as the old-style serial port units do not work properly.

The apcupsd daemon can be used to monitor the UPS. If your distribution does not already have it, the package can be installed.

  • If using Fedora, run yum -y install apcupsd (substitute your package installer as appropriate)

  • Comment out the WALL statement in the /etc/apcupsd/apccontrol file to keep annoying messages from being broadcasted to every terminal

  • Run apcaccess status to query the UPS

There's quite a bit more you can do with apcupsd, for more information check its website at http://www.apcupsd.com. This also lists some UPS units that might not be as compatible with Linux as the ones I have.

One more thing, you will probably want to use the auto-shutdown feature of the UPS. It can be set up to automatically shutdown your machine if the power has been out for too long. Most units allow you to set the amount of time to stay running, before shutting down. Remember that the longer the UPS runs on the batteries, the shorter their life span will be.