Many experienced Linux users, historically, have not been satisfied with the patch management tools of the two Linux market leaders, Red Hat and SUSE. Their problems are, in part, related to their reliance on distribution-specific patch management tools. As we've seen in Chapters 1-3, SUSE's YaST Online Update and the Red Hat Update Agent are both excellent tools. Unfortunately, these tools are not easily used on other distributions, and they create bureaucratic filters on the contributions of the Linux community. In addition, they do not have the broad level of community support available for the apt or even the Smart Program Manager commands.
This lack of satisfaction began to change with the first release of Fedora Linux in the fall of 2003. As Red Hat moved toward a subscription support model for its Enterprise Linux distribution, Red Hat simultaneously moved toward the community with the Fedora Linux project. To enhance community support for Fedora, Red Hat incorporated the work of the Yellow Dog distribution on patch management. Their tool is known as yum, short for Yellowdog Updater, Modified. With the Fedora apt repositories described in Chapter 5, "Configuring apt for RPM Distributions," along with the Red Hat Update Agent described in Chapter 2, "Consolidating Patches on a Red Hat/Fedora Network," Fedora now incorporates a variety of tools for patch management.
The changes continued with the acquisition of SUSE by Novell in early 2004. As you've seen in Chapter 3, "SUSE's Update Systems and rsync Mirrors," SUSE has already incorporated its Online Update server in YaST. Novell has also incorporated Linux in its Zenworks system for patch management (formerly known as Red Carpet). As of this writing, it is too early to assess the response of the Linux community to the Zenworks Linux Management patch update tool.
In other words, if you want to manage patches on RPM-based distributions with tools familiar to the Linux community, you can use either yum or apt. Some developers prefer yum because it is customized for RPM-based distributions, especially those released by Red Hat. Others prefer apt because of the associated levels of community support. The yum commands are also supported by Fedora, AspLinux of Russia, and Yellow Dog Linux.
In this chapter, we will extend our discussion of yum for various Linux clients to show you how it can help you manage patches on a variety of RPM-based distributions. But first, we explore the history and workings of yum as an RPM-based system.