6. Package Management

RPM provides support for signed packages using strong hash algorithms such as SHA-256 in order to ensure package integrity and increase security. Red Hat Enterprise Linux 6 packages are transparently compressed with the XZ lossless compression library, which implements the LZMA2 compression algorithm for greater compression (thus reducing package size) and speedier unpacking (when installing RPMs). Further information on the stronger package checksums is available in the Deployment Guide

Red Hat provides PackageKit for viewing, managing, updating, installing and uninstalling packages and package groups compatible with your system, and enabled in Yum repositories. PackageKit consists of several graphical interfaces that can be opened from the GNOME panel menu, or from the Notification Area, when PackageKit alerts you that updates are available. Additionally, PackageKit allows for quick repository enablement and disablement, a graphical and searchable transaction log, and PolicyKit integration. Futher information on Package Kit is available in the Deployment Guide

Via its plugin architecture, Yum provides new or enhanced support for various capabilities such as delta RPMs (using the presto plugin), RHN communication (rhnplugin), and auditing and applying—using a calculated least-invasive (minimal) number of updates—only relevant security fixes to a system (security plugin).

Yum also ships with the yum-config-manager utility, which shows exhaustive information about all set configuration options and parameters for each individual repository. Further information on updates to Yum is available in the Deployment Guide