B.2.2. Installing and Upgrading RPM packages typically have file names like tree-1.5.3-2.el6.x86_64.rpm . The file name includes the package name ( tree ), version ( 1.5.3 ), release ( 2 ), operating system major version ( el6 ) and CPU architecture ( x86_64 ). You can use rpm 's -U option to: upgrade an existing but older package on the system to a newer version, or install the package even if an older version is not already installed. That is, rpm -U <rpm_file> is able to perform the function of either upgrading or installing as is appropriate for the package. Assuming the tree-1.5.3-2.el6.x86_64.rpm package is in the current directory, log in as root and type the following command at a shell prompt to either upgrade or install the tree package as determined by rpm : Note The -v and -h options (which are combined with -U ) cause rpm to print more verbose output and display a progress meter using hash signs. If the upgrade/installation is successful, the following output is displayed: Warning rpm provides two different options for installing packages: the aforementioned -U option (which historically stands for upgrade ), and the -i option, historically standing for install . Because the -U option subsumes both install and upgrade functions, we recommend to use rpm -Uvh with all packages except kernel packages. You should always use the -i option to install a new kernel package instead of upgrading it. This is because using the -U option to upgrade a kernel package removes the (older) kernel package, which could render the system unable to boot if there is a problem with the new kernel. Therefore, use the rpm -i <kernel_package> command to install a new kernel without replacing any older kernel packages. For more information on installing kernel packages, see Chapter 30, Manually Upgrading the Kernel . The signature of a package is checked automatically when installing or upgrading a package. The signature confirms that the package was signed by an authorized party. For example, if the verification of the signature fails, an error message such as the following is displayed: If it is a new, header-only, signature, an error message such as the following is displayed: If you do not have the appropriate key installed to verify the signature, the message contains the word NOKEY : See Section B.3, "Checking a Package's Signature" for more information on checking a package's signature. B.2.2.1. Package Already Installed If a package of the same name and version is already installed, the following output is displayed: However, if you want to install the package anyway, you can use the --replacepkgs option, which tells RPM to ignore the error: This option is helpful if files installed from the RPM were deleted or if you want the original configuration files from the RPM to be installed. B.2.2.2. Conflicting Files If you attempt to install a package that contains a file which has already been installed by another package, the following is displayed: To make RPM ignore this error, use the --replacefiles option: B.2.2.3. Unresolved Dependency RPM packages may sometimes depend on other packages, which means that they require other packages to be installed to run properly. If you try to install a package which has an unresolved dependency, output similar to the following is displayed: If you are installing a package from the Red Hat Enterprise Linux installation media, such as from a CD-ROM or DVD, the dependencies may be available. Find the suggested package(s) on the Red Hat Enterprise Linux installation media or on one of the active Red Hat Enterprise Linux mirrors and add it to the command: If installation of both packages is successful, output similar to the following is displayed: You can try the --whatprovides option to determine which package contains the required file. If the package that contains bar.so.3 is in the RPM database, the name of the package is displayed: Warning Although we can force rpm to install a package that gives us a Failed dependencies error (using the --nodeps option), this is not recommended, and will usually result in the installed package failing to run. Installing or removing packages with rpm --nodeps can cause applications to misbehave and/or crash, and can cause serious package management problems or, possibly, system failure. For these reasons, it is best to heed such warnings; the package manager-whether RPM , Yum or PackageKit -shows us these warnings and suggests possible fixes because accounting for dependencies is critical. The Yum package manager can perform dependency resolution and fetch dependencies from online repositories, making it safer, easier and smarter than forcing rpm to carry out actions without regard to resolving dependencies.

Commands:
-Uvh tree-1.5.3-2.el6.x86_64.rpm
Preparing... ########################################### [100%] 1:tree ########################################### [100%]
error: tree-1.5.3-2.el6.x86_64.rpm: Header V3 RSA/SHA256 signature: BAD, key ID d22e77f2
error: tree-1.5.3-2.el6.x86_64.rpm: Header V3 RSA/SHA256 signature: BAD, key ID d22e77f2
warning: tree-1.5.3-2.el6.x86_64.rpm: Header V3 RSA/SHA1 signature: NOKEY, key ID 57bbccba
Preparing... ########################################### [100%] package tree-1.5.3-2.el6.x86_64 is already installed
-Uvh --replacepkgs tree-1.5.3-2.el6.x86_64.rpm
Preparing... ################################################## file /usr/bin/foobar from install of foo-1.0-1.el6.x86_64 conflicts with file from package bar-3.1.1.el6.x86_64
-Uvh --replacefiles foo-1.0-1.el6.x86_64.rpm
error: Failed dependencies: bar.so.3()(64bit) is needed by foo-1.0-1.el6.x86_64
-Uvh foo-1.0-1.el6.x86_64.rpm bar-3.1.1.el6.x86_64.rpm
Preparing... ########################################### [100%] 1:foo ########################################### [ 50%] 2:bar ########################################### [100%]
-q --whatprovides "bar.so.3"
bar-3.1.1.el6.i586.rpm