It's important to keep Linux computers up to date. Linux developers are constantly updating key services to enhance security, add features you need, fix bugs that hinder your productivity and the productivity of your users, and help your systems to work more efficiently. These updates are known as patches. Most Linux distributions make gigabytes of patches available over the Internet. These updates cannot help you unless you know how to manage patches for the different Linux systems on your network.
This book assumes you have some sort of high-speed Internet connection that can help you download these patches. You may need to download hundreds of megabytes of patches, and that is not realistic on a 56Kbps telephone modem. If you have to download hundreds of megabytes on all the Linux computers in your office, you might overload all but the fastest business-quality high-speed connections.
In this book, I describe how you can manage patches on Red Hat/Fedora, SUSE, and Debian Linux systems. While Red Hat and SUSE have developed specialized update tools for their distributions, it's also possible to use community tools, such as apt and yum, on many Linux distributions.
To this end, you can use this book as a guide to managing patches on the noted distributions. In addition, you can use apt and yum on a number of other Linux systems. As a Linux administrator, you can use this book to learn to manage the hundreds of megabytes, or even gigabytes, of patches on a wide variety of Linux systems.
After you learn to manage patches on individual Linux systems, you can extend those skills to managing a group of Linux computers on a network. If you have a sufficient number of Linux systems, you may even want to build your own patch management repositories.
Patches on one or two Linux computers may work well with a standard high-speed Internet connection. If you have a substantial number of Linux computers, you might download the patches from each of these computers over the Internet. To keep these downloads from overloading your Internet connection, you can pay a premium for an even higher-speed connection.
Alternatively, you can use the techniques described in this book to configure a local patch management repository. This can help you avoid buying a faster high-speed Internet connection. Thus, a patch management repository can help you save a lot of money. In addition, you can update a group of computers more quickly when you download patches from a local repository.
Red Hat supports patch management on a group of Red Hat Enterprise Linux (RHEL) computers through the Red Hat Network. SUSE supports patch management on a group of SUSE Enterprise Linux Server and Workstation computers with YaST Online Update and Zenworks Linux Management. You can use these tools to manage patches on individual systems or on networks of these distributions. Red Hat and SUSE provide these tools to help you manage patches. If you have a large number of systems, these tools can help you keep the loads on your Internet connection to a minimum and speed up the updates you need.
But this book is not limited to Red Hat and SUSE Linux. It also can help you keep the loads on your Internet connection to a minimum when managing other distributions, including Debian and Fedora Linux. It also uses the tools designed by Conectiva (now Mandriva) for RPM-based distributions. The skills you learn can help you manage patches on allied distributions, including Yellowdog, Ubuntu, Progeny, Lycoris, and the "rebuild" distributions that use the source code released for Red Hat Enterprise Linux.