ServerBuddies Support Blog

Yum Package Manager

Yum is an automatic updater and package installer/remover for rpm systems. It 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. Yum has a plugin interface for adding simple features. Yum can also be used from other python programs via its module inteface.

Get Yum (3.4.1, or older versions)

Download yum-3.4.1.tar.gz

Verifying Signed Packages

All Red Hat Enterprise Linux packages are signed with the Red Hat GPG key. GPG stands for GNU Privacy Guard, or GnuPG, a free software package used for ensuring the authenticity of distributed files. For example, a private key (secret key) locks the package while the public key unlocks and verifies the package. If the public key distributed by Red Hat Enterprise Linux does not match the private key during RPM verification, the package may have been
altered and therefore cannot be trusted.

If the disc is mounted in /mnt/cdrom, use the following command to import it into the keyring (a database of trusted keys on the system):

To display a list of all keys installed for RPM verification, execute the following command:

The output will look similar to the following:

To display details about a specific key, use the rpm -qi command followed by the output from the previous command, as in this example:

How to install or add a package in FreeBSD

To install a Port: (ImageMagick as an example)

If you do not have a source of local packages (such as a FreeBSD CD-ROM set) then it will probably be easier to use the -r option to pkg_add(1). This will cause the utility to automatically determine the correct object format and release and then fetch and install the package from an FTP site.

The example above would download the correct package and add it without any further user intervention.

pkg_info(1) is a utility that lists and describes the various packages installed.

To remove a previously installed software package, use the pkg_delete(1) utility.

How do I apply package updates from the Red Hat Network?

Systems must be registered before updates from RHN can be applied. This can be done by using the “Software Updater” application from the “System Tools” menu, or via the command line by using the “rhn_register” command.

To access updates from RHN when using Red Hat Enterprise Linux 5, launch the graphical update tool through Applications -> System Tools -> Software Updater, or from the command line via the following command:

For a command line interface, use the following command to update the operating system:

To install a specific package, such as elinks, use the following command:

To update a specific package, such as httpd, use the following command:

How do I install or upgrade an RPM package?

In order to install an RPM package you must first have the RPM you are trying to install on your system. Many people will download RPMs from a website and of course, Red Hat Network (RHN) provides all the RPM packages included in the distributions. There are two main flags that are used to install or upgrade RPM packages:

-i is used to install a new package. Always use this for kernel installations and upgrades.
-U is used to upgrade an RPM package but will also install a package if it does not exist in the RPM database.

Usage and additional options can be found in the RPM man page. Type man rpm from the command line.

Here is some information about the -i and -U flags:

INSTALL AND UPGRADE OPTIONS