Updating Red Hat and Fedora Linux with RHN, Yum and APT

New versions of Red Hat Fedora are released every few months, and for Red Hat Enterprise every year or so. In the meantime, new updates are continually being prepared for particular software packages. These are posted as updates you can download from software repositories and install on your system. These include new versions of applications, servers, and even the kernel. Such updates may range from single software packages to whole components—for instance, all the core, application, and development packages issued when a new release of GNOME, KDE, or XFree86 is made available.

Updating your Linux system has become a very simple procedure, using the automatic update tools. For the Fedora Core, you can update your system by accessing software repositories supporting either Yum (Yellowdog Update, Modified) or apt-rpm (Advanced Package Tool RPM) update methods. Yum uses RPM headers to determine which packages need to be updated. You can find out more about Yum, including a listing of Yum repositories, at linux.duke.edu/projects/yum. APT is a more complex update method originally implemented for Debian Linux.

The easiest way to update Fedora is to start the Red Hat Update Agent (up2date) by selecting the Red Hat Network (RHN) entry from the System Tools menu. Although reserved for use by Red Hat Enterprise Linux, on the Fedora Core you can use the Red Hat Update Agent to access the Fedora Core Yum repository, letting you update quickly to the most recent software versions. Two channels are provided, one for the Fedora release and one for updates. You can add a third testing channel for the newest releases (replaces Rawhide releases). A list of packages that can be updated will be displayed, from which you can select the ones you want to update. To access other Yum repositories you can configure the /etc/sysconfig/rhn/sources file to access them with the Red Hat Update Agent. You can also use the yum command, designating Yum repositories in the /etc/yum.conf file. Current Fedora Yum repositories are listed here, with the version number changing with each release.

• fedora.redhat.com/releases/fedora-core-1

• fedora.redhat.com/updates/released/fedora-core-1

• fedora.redhat.com/updates/testing/fedora-core-1

To update to a new Fedora Core release, you can download Fedora Core CD-ROM ISO images from fedora.redhat.com/releases/fedora-core. ISO images can also be downloaded using rpmfind's BitTorrent service (see rpmfind.net/BitTorrent). BitTorrent provides a very fast method for downloading ISO images.

For Red Hat Enterprise Linux, you can automatically update your system by registering as part of the Red Hat Network. The Red Hat Network service now supports only Red Hat Enterprise Linux, not Fedora Core Linux (although the RHN tool can be configured to access Fedora repositories). Registering with and configuring access to the Red Hat Network is a very simple procedure, using the Red Hat Network Registration client. The Red Hat Network is a subscription service included with your purchase of an enterprise package. Once you register with the Red Hat Network, you can use the Red Hat Update Agent to download and install Red Hat Enterprise updates almost automatically.

Tip

If you installed Ximian Desktop (see Chapter 6), you can use Ximian's Red Carpet update utility to update your system.