Chapter 8. Yum Red Hat Customer Portal.Yum is the Red Hat package manager that is able to query for information about available packages, fetch packages from repositories, install and uninstall them, and update an entire system to the latest available version.Yum performs automatic dependency resolution when updating, installing, or removing packages, and thus is able to automatically determine, fetch, and install all available dependent packages.Yum can be configured with new, additional repositories, or package sources, and also provides many plug ins which enhance and extend its capabilities.Yum is able to perform many of the same tasks that RPM can additionally, many of the command line options are similar.Yum enables easy and simple package management on a single machine or on groups of them.Yum provides secure package management by enabling GPG Gnu Privacy Guard also known as Gnu.Ea1Rl.png' alt='Rhel 6 Yum Install X11 Redhat' title='Rhel 6 Yum Install X11 Redhat' />PG signature verification on GPG signed packages to be turned on for all package repositories package sources, or for individual repositories.When signature verification is enabled, yum will refuse to install any packages not GPG signed with the correct key for that repository.This means that you can trust that the RPM packages you download and install on your system are from a trusted source, such as Red Hat, and were not modified during transfer.See Section 8. 5, Configuring Yum and Yum Repositories for details on enabling signature checking with yum, or Section A.Checking Package Signatures for information on working with and verifying GPG signed RPM packages in general.Yum also enables you to easily set up your own repositories of RPM packages for download and installation on other machines.The one I will discuss in this article is SSH, a secure remote protocol which is used to work remotely on other machines or transfer data between computers.When possible, yum uses parallel download of multiple packages and metadata to speed up downloading.Learning yum is a worthwhile investment because it is often the fastest way to perform system administration tasks, and it provides capabilities beyond those provided by the Package.Kit graphical package management tools.You must have superuser privileges in order to use yum to install, update or remove packages on your system.All examples in this chapter assume that you have already obtained superuser privileges by using either the su or sudo command.Yum enables you to check if your system has any updates waiting to be applied.You can list packages that need to be updated and update them as a whole, or you can update a selected individual package.Checking For Updates.To see which installed packages on your system have updates available, use the following command.Example 8. 1. Example output of the yum check update command.The output of yumcheck update can look as follows.Loaded plugins product id, search disabled repos, subscription manager.The packages in the above output are listed as having updates available.Rhel 6 Yum Install X11 Redhat' title='Rhel 6 Yum Install X11 Redhat' />The first package in the list is dracut.Each line in the example output consists of several rows, in case of dracut.CPU architecture the package was built for.The output also shows that we can update the kernel the kernel package, yum and RPM themselves the yum and rpm packages, as well as their dependencies such as the rpm libs, and rpm python packages, all using the yum command.You can choose to update a single package, multiple packages, or all packages at once.If any dependencies of the package or packages you update have updates available themselves, then they are updated too.Updating a Single Package.To update a single package, run the following command as root.If you add the installonlypkgs directive to etcyum.Yum is the Red Hat package manager that is able to query for information about available packages, fetch packages from repositories, install and uninstall them, and.Example 8. 2. Updating the rpm package.To update the rpm package, type.Loaded plugins langpacks, product id, subscription manager.Updating Red Hat repositories.INFO rhsm app. repolib repos updated 0.Setting up Update Process.Resolving Dependencies.Running transaction check.Package rpm. x. 866.Processing Dependency rpm 4.Processing Dependency rpm 4.Processing Dependency rpm 4.Package rpm. x. 866.Running transaction check.Finished Dependency Resolution.Dependencies Resolved.Package Arch Version Repository Size.M. Updating for dependencies.Transaction Summary.Upgrade 1 Package 4 Dependent packages.Total size 1. 7 M.Is this ok ydN. This output contains several items of interest.Transaction check is performed for each of these packages.Yum presents the update information and then prompts you for confirmation of the update yum runs interactively by default.If you already know which transactions the yum command plans to perform, you can use the y option to automatically answer yes to any questions that yum asks in which case it runs non interactively.However, you should always examine which changes yum plans to make to the system so that you can easily troubleshoot any problems that might arise. Air Talkie Walkie Torrent Flac Ty . You can also choose to download the package without installing it.To do so, select the d option at the download prompt.This launches a background download of the selected package.Yum always installs a new kernel regardless of whether you are using the yum update or yum install command.When using RPM, on the other hand, it is important to use the rpm i kernel command which installs a new kernel instead of rpm u kernel which replaces the current kernel.See Section A. 2.Installing and Upgrading Packages for more information on installing and upgrading kernels with RPM.Similarly, it is possible to update a package group.Type as root. yum group updategroupname.Yum also offers the upgrade command that is equal to update with enabled obsoletes configuration option see Section 8.Setting main Options.By default, obsoletes is turned on in etcyum.Updating All Packages and Their Dependencies.To update all packages and their dependencies, use the yum update command without any arguments.If packages have security updates available, you can update only these packages to their latest versions.Type as root. yum update security.You can also update packages only to versions containing the latest security updates.Type as root. yum update minimal security.For example, assume that.Then yum update minimal security updates the package to kernel 3.Preserving Configuration File Changes.You will inevitably make changes to the configuration files installed by packages as you use your Red Hat Enterprise Linux system.RPM, which yum uses to perform changes to the system, provides a mechanism for ensuring their integrity.See Section A. 2.Installing and Upgrading Packages for details on how to manage changes to configuration files across package upgrades.Upgrading the System Off line with ISO and Yum.For systems that are disconnected from the Internet or Red Hat Network, using the yum update command with the Red Hat Enterprise Linux installation ISO image is an easy and quick way to upgrade systems to the latest minor version.The following steps illustrate the upgrading process.Create a target directory to mount your ISO image.This directory is not automatically created when mounting, so create it before proceeding to the next step.As root, type. mkdirmountdir.Replace mountdir with a path to the mount directory.Typically, users create it as a subdirectory in the media directory.Mount the Red Hat Enterprise Linux 7 installation ISO image to the previously created target directory.As root, type. mount oloopisonamemountdir.Replace isoname with a path to your ISO image and mountdir with a path to the target directory.Here, the oloop option is required to mount the file as a block device.Copy the media. repo file from the mount directory to the etcyum.Note that configuration files in this directory must have the.This creates a configuration file for the yum repository.Replace new. repo with the filename, for example rhel.Edit the new configuration file so that it points to the Red Hat Enterprise Linux installation ISO.Add the following line into the etcyum.Replace mountdir with a path to the mount point.Update all yum repositories including etcyum.As root, type. This upgrades your system to the version provided by the mounted ISO image.After successful upgrade, you can unmount the ISO image.As root, type. umountmountdir.Also, you can remove the mount directory created in the first step.As root, type. rmdirmountdir.If you will not use the previously created configuration file for another installation or update, you can remove it.As root, type. rmetcyum.Example 8. 3. Upgrading from Red Hat Enterprise Linux 7.
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