Yum (Yellowdog Updater Modified) is a powerful automatic updater and package installer/remover on RPM-based Linux distributions like Red Hat / Fedora.
Yum automatically computes dependencies and figures out what things should occur to install packages. It makes it easier to maintain groups of machines without having to manually update each one using rpm.
The main Yum configuration file is /etc/yum.conf. Basic repository listings are located in the /etc/yum.repos.d/ directory. Unless you plan on adding other repositories or have a need to tweak certain configuration settings, these configuration files work as-is. Please refer to yum.conf manual page to find out the various options for this configuration file. You may like to take note about the keepcache option in this file. Set keepcache=1 if you want to keep the downloaded RPM files from erased after they are installed. However, make sure the cachedir directory has enough space to save the downloaded files. Continue reading