Installing RPMs

There are three basic commands that may install an RPM. They won't work if there are dependencies (packages that need to be installed first). For example, if you haven't installed Samba and try to install the system-config-samba package, you'll get the following message (your version numbers may be different):

# rpm -i system-config-samba-*
error: Failed dependencies:
samba is needed by system-config-samba-1.2.39-1.1.noarch

Sure, you can use the --force option to make rpm ignore dependencies, but that can lead to other problems, unless you install those dependencies as soon as possible. The best option is to use an appropriate yum command. In this case, a yum install system-config-samba command would automatically install the Samba RPM as well.

If you're not stopped by dependencies, there are three basic commands that can install RPM packages:

# rpm -i packagename

# rpm -U packagename

# rpm -F packagename

The rpm -i option installs the package, if it isn't already installed. The rpm -U option upgrades any existing package or installs it if an earlier version isn't already installed. The rpm -F option upgrades only existing packages. It does not install a package if it wasn't previously installed.

I like to add the -vh options whenever I use the rpm command. These options add verbose mode and use hash marks to help you monitor the progress of the installation. So when I use rpm to install a package, I run

# rpm -ivh packagename

There's one more thing the rpm command does before installing a package: it checks to see whether it would overwrite any configuration files. The rpm command tries to make intelligent decisions about what to do in this situation. As suggested earlier, if the rpm command chooses to replace an existing configuration file, it gives you a warning (in most cases like:

# rpm -i penguin-3.26.i386.rpm
warning: /etc/someconfig.conf saved as /etc/someconfig.conf.rpmsave

It's up to you to look at both files and determine what, if any, modifications need to be made.

If you've already customized a package and upgraded it with rpm, go to the saved configuration file. Use it as a guide to change the settings in the new configuration file. Since you may need to make different changes to the new configuration file, you should test the result for every situation in which the package may be used in a production environment.