Chapter 9. Yum

To see which installed packages on your system have updates available, use the following command:

yum check-update

~]# yum check-update
Loaded plugins: product-id, search-disabled-repos, subscription-manager
dracut.x86_64             033-360.el7_2   rhel-7-server-rpms
dracut-config-rescue.x86_64      033-360.el7_2   rhel-7-server-rpms
kernel.x86_64             3.10.0-327.el7   rhel-7-server-rpms
rpm.x86_64              4.11.3-17.el7   rhel-7-server-rpms
rpm-libs.x86_64            4.11.3-17.el7   rhel-7-server-rpms
rpm-python.x86_64           4.11.3-17.el7   rhel-7-server-rpms
yum.noarch              3.4.3-132.el7   rhel-7-server-rpms

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:

yum update package_name

~]# yum update rpm
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.x86_64 0:4.11.1-3.el7 will be updated
--> Processing Dependency: rpm = 4.11.1-3.el7 for package: rpm-libs-4.11.1-3.el7.x86_64
--> Processing Dependency: rpm = 4.11.1-3.el7 for package: rpm-python-4.11.1-3.el7.x86_64
--> Processing Dependency: rpm = 4.11.1-3.el7 for package: rpm-build-4.11.1-3.el7.x86_64
---> Package rpm.x86_64 0:4.11.2-2.el7 will be an update
--> Running transaction check
...
--> Finished Dependency Resolution

Dependencies Resolved
=============================================================================
 Package          Arch    Version     Repository    Size
=============================================================================
Updating:
 rpm            x86_64   4.11.2-2.el7  rhel      1.1 M
Updating for dependencies:
 rpm-build         x86_64   4.11.2-2.el7  rhel      139 k
 rpm-build-libs      x86_64   4.11.2-2.el7  rhel       98 k
 rpm-libs         x86_64   4.11.2-2.el7  rhel      261 k
 rpm-python        x86_64   4.11.2-2.el7  rhel       74 k

Transaction Summary
=============================================================================
Upgrade 1 Package (+4 Dependent packages)

Total size: 1.7 M
Is this ok [y/d/N]:

Similarly, it is possible to update a package group. Type as root:

yum group update group_name

Here, replace group_name with a name of the package group you want to update. For more information on package groups, see Section 9.3, “Working with Package Groups”.

Yum also offers the upgrade command that is equal to update with enabled obsoletes configuration option (see Section 9.5.1, “Setting [main] Options”). By default, obsoletes is turned on in /etc/yum.conf, which makes these two commands equivalent.

yum update

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-3.10.0-2, and yum update --security updates the package to kernel-3.10.0-3.

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:

~]# mount -o loop
    rhel-server-7.1-x86_64-dvd.iso /media/rhel7/

~]# cp /media/rhel7/media.repo /etc/yum.repos.d/rhel7.repo

baseurl=file:///media/rhel7/

~]# yum update

~]# umount /media/rhel7/

~]# rmdir /media/rhel7/

~]# rm
     /etc/yum.repos.d/rhel7.repo

You can search all RPM package names, descriptions and summaries by using the following command:

yum search term…

Replace term with a package name you want to search.

~]$ yum search vim gvim emacs
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
============================= N/S matched: vim ==============================
vim-X11.x86_64 : The VIM version of the vi editor for the X Window System
vim-common.x86_64 : The common files needed by any version of the VIM editor
[output truncated]

============================ N/S matched: emacs =============================
emacs.x86_64 : GNU Emacs text editor
emacs-auctex.noarch : Enhanced TeX modes for Emacs
[output truncated]

 Name and summary matches mostly, use "search all" for everything.
Warning: No matches found for: gvim

The yum search command is useful for searching for packages you do not know the name of, but for which you know a related term. Note that by default, yum search returns matches in package name and summary, which makes the search faster. Use the yum search all command for a more exhaustive but slower search.

Be careful to escape the glob expressions when passing them as arguments to a yum command, otherwise the Bash shell will interpret these expressions as pathname expansions, and potentially pass all files in the current directory that match the global expressions to yum. To make sure the glob expressions are passed to yum as intended, use one of the following methods:

Examples in the following section demonstrate usage of both these methods.

To list information on all installed and available packages type the following at a shell prompt:

yum list all

To list installed and available packages that match inserted glob expressions use the following command:

yum list glob_expression…

~]$ yum list abrt-addon\* abrt-plugin\*
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Installed Packages
abrt-addon-ccpp.x86_64          2.1.11-35.el7       @rhel-7-server-rpms
abrt-addon-kerneloops.x86_64       2.1.11-35.el7       @rhel-7-server-rpms
abrt-addon-pstoreoops.x86_64       2.1.11-35.el7       @rhel-7-server-rpms
abrt-addon-python.x86_64         2.1.11-35.el7       @rhel-7-server-rpms
abrt-addon-vmcore.x86_64         2.1.11-35.el7       @rhel-7-server-rpms
abrt-addon-xorg.x86_64          2.1.11-35.el7       @rhel-7-server-rpms

To list all packages installed on your system use the installed keyword. The rightmost column in the output lists the repository from which the package was retrieved.

yum list installed glob_expression…

~]$ yum list installed "krb?-*"
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Installed Packages
krb5-libs.x86_64         1.13.2-10.el7          @rhel-7-server-rpms

To list all packages in all enabled repositories that are available to install, use the command in the following form:

yum list available glob_expression…

~]$ yum list available gstreamer*plugin\*
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Available Packages
gstreamer-plugins-bad-free.i686       0.10.23-20.el7     rhel-7-server-rpms
gstreamer-plugins-base.i686         0.10.36-10.el7     rhel-7-server-rpms
gstreamer-plugins-good.i686         0.10.31-11.el7     rhel-7-server-rpms
gstreamer1-plugins-bad-free.i686      1.4.5-3.el7      rhel-7-server-rpms
gstreamer1-plugins-base.i686        1.4.5-2.el7      rhel-7-server-rpms
gstreamer1-plugins-base-devel.i686     1.4.5-2.el7      rhel-7-server-rpms
gstreamer1-plugins-base-devel.x86_64    1.4.5-2.el7      rhel-7-server-rpms
gstreamer1-plugins-good.i686        1.4.5-2.el7      rhel-7-server-rpms

yum repolist

To list more information about these repositories, add the -v option. With this option enabled, information including the file name, overall size, date of the last update, and base URL are displayed for each listed repository. As an alternative, you can use the repoinfo command that produces the same output.

yum repolist -v

yum repoinfo

To list both enabled and disabled repositories use the following command. A status column is added to the output list to show which of the repositories are enabled.

yum repolist all

By passing disabled as a first argument, you can reduce the command output to disabled repositories. For further specification you can pass the ID or name of repositories or related glob_expressions as arguments. Note that if there is an exact match between the repository ID or name and the inserted argument, this repository is listed even if it does not pass the enabled or disabled filter.

To display information about one or more packages, use the following command (glob expressions are valid here as well):

yum info package_name…

Replace package_name with the name of the package.

~]$ yum info abrt
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Installed Packages
Name    : abrt
Arch    : x86_64
Version   : 2.1.11
Release   : 35.el7
Size    : 2.3 M
Repo    : installed
From repo  : rhel-7-server-rpms
Summary   : Automatic bug detection and reporting tool
URL     : https://fedorahosted.org/abrt/
License   : GPLv2+
Description : abrt is a tool to help users to detect defects in applications and
      : to create a bug report with all information needed by maintainer to fix
      : it. It uses plugin system to extend its functionality.

The yum info package_name command is similar to the rpm -q --info package_name command, but provides as additional information the name of the yum repository the RPM package was installed from (look for the From repo: line in the output).

yumdb info package_name

This command provides additional information about a package, including the check sum of the package (and the algorithm used to produce it, such as SHA-256), the command given on the command line that was invoked to install the package (if any), and the reason why the package is installed on the system (where user indicates it was installed by the user, and dep means it was brought in as a dependency).

~]$ yumdb info yum
Loaded plugins: langpacks, product-id
yum-3.4.3-132.el7.noarch
   changed_by = 1000
   checksum_data = a9d0510e2ff0d04d04476c693c0313a11379053928efd29561f9a837b3d9eb02
   checksum_type = sha256
   command_line = upgrade
   from_repo = rhel-7-server-rpms
   from_repo_revision = 1449144806
   from_repo_timestamp = 1449144805
   installed_by = 4294967295
   origin_url = https://cdn.redhat.com/content/dist/rhel/server/7/7Server/x86_64/os/Packages/yum-3.4.3-132.el7.noarch.rpm
   reason = user
   releasever = 7Server
   var_uuid = 147a7d49-b60a-429f-8d8f-3edb6ce6f4a1

For more information on the yumdb command, see the yumdb(8) manual page.

To install a single package and all of its non-installed dependencies, enter a command in the following form as root:

yum install package_name

You can also install multiple packages simultaneously by appending their names as arguments. To do so, type as root:

yum install package_name package_name…

If you are installing packages on a multilib system, such as an AMD64 or Intel 64 machine, you can specify the architecture of the package (as long as it is available in an enabled repository) by appending .arch to the package name:

yum install package_name.arch

~]# yum install sqlite.i686

You can use glob expressions to quickly install multiple similarly named packages. Execute as root:

yum install glob_expression…

~]# yum install audacious-plugins-\*

In addition to package names and glob expressions, you can also provide file names to yum install. If you know the name of the binary you want to install, but not its package name, you can give yum install the path name. As root, type:

yum install /usr/sbin/named

Yum then searches through its package lists, finds the package which provides /usr/sbin/named, if any, and prompts you as to whether you want to install it.

As you can see in the above examples, the yum install command does not require strictly defined arguments. It can process various formats of package names and glob expressions, which makes installation easier for users. On the other hand, it takes some time until yum parses the input correctly, especially if you specify a large number of packages. To optimize the package search, you can use the following commands to explicitly define how to parse the arguments:

yum install-n name

yum install-na name.architecture

yum install-nevra name-epoch:version-release.architecture

With install-n, yum interprets name as the exact name of the package. The install-na command tells yum that the subsequent argument contains the package name and architecture divided by the dot character. With install-nevra, yum will expect an argument in the form name-epoch:version-release.architecture. Similarly, you can use yum remove-n, yum remove-na, and yum remove-nevra when searching for packages to be removed.

~]# yum provides "*bin/named"
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-
       : manager
32:bind-9.9.4-14.el7.x86_64 : The Berkeley Internet Name Domain (BIND) DNS
              : (Domain Name System) server
Repo    : rhel-7-server-rpms
Matched from:
Filename  : /usr/sbin/named

~]# yum install httpd
Loaded plugins: langpacks, product-id, subscription-manager
Resolving Dependencies
--> Running transaction check
---> Package httpd.x86_64 0:2.4.6-12.el7 will be updated
---> Package httpd.x86_64 0:2.4.6-13.el7 will be an update
--> Processing Dependency: 2.4.6-13.el7 for package: httpd-2.4.6-13.el7.x86_64
--> Running transaction check
---> Package httpd-tools.x86_64 0:2.4.6-12.el7 will be updated
---> Package httpd-tools.x86_64 0:2.4.6-13.el7 will be an update
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package    Arch   Version         Repository        Size
================================================================================
Updating:
 httpd     x86_64  2.4.6-13.el7      rhel-x86_64-server-7  1.2 M
Updating for dependencies:
 httpd-tools  x86_64  2.4.6-13.el7      rhel-x86_64-server-7   77 k

Transaction Summary
================================================================================
Upgrade 1 Package (+1 Dependent package)

Total size: 1.2 M
Is this ok [y/d/N]:

Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
 Updating  : httpd-tools-2.4.6-13.el7.x86_64               1/4
 Updating  : httpd-2.4.6-13.el7.x86_64                  2/4
 Cleanup  : httpd-2.4.6-12.el7.x86_64                  3/4
 Cleanup  : httpd-tools-2.4.6-12.el7.x86_64               4/4
 Verifying : httpd-2.4.6-13.el7.x86_64                  1/4
 Verifying : httpd-tools-2.4.6-13.el7.x86_64               2/4
 Verifying : httpd-tools-2.4.6-12.el7.x86_64               3/4
 Verifying : httpd-2.4.6-12.el7.x86_64                  4/4

Updated:
 httpd.x86_64 0:2.4.6-13.el7

Dependency Updated:
 httpd-tools.x86_64 0:2.4.6-13.el7

Complete!

To install a previously downloaded package from the local directory on your system, use the following command:

yum localinstall path

Replace path with the path to the package you want to install.

As shown in Example 9.12, “Installation Process”, at a certain point of installation process you are prompted to confirm the installation with the following message:

...
Total size: 1.2 M
Is this ok [y/d/N]:
...

With the d option, yum downloads the packages without installing them immediately. You can install these packages later offline with the yum localinstall command or you can share them with a different device. Downloaded packages are saved in one of the subdirectories of the cache directory, by default /var/cache/yum/$basearch/$releasever/packages/. The downloading proceeds in background mode so that you can use yum for other operations in parallel.

Similarly to package installation, yum enables you to uninstall them. To uninstall a particular package, as well as any packages that depend on it, run the following command as root:

yum remove package_name…

As when you install multiple packages, you can remove several at once by adding more package names to the command.

~]# yum remove totem

Similar to install, remove can take these arguments:

The summary option is used to view the number of installed groups, available groups, available environment groups, and both installed and available language groups:

yum groups summary

~]$ yum groups summary
Loaded plugins: langpacks, product-id, subscription-manager
Available Environment Groups: 12
Installed Groups: 10
Available Groups: 12

To list all package groups from yum repositories add the list option. You can filter the command output by group names.

yum group list glob_expression…

Several optional arguments can be passed to this command, including hidden to list also groups not marked as user visible, and ids to list group IDs. You can add language, environment, installed, or available options to reduce the command output to a specific group type.

To list mandatory and optional packages contained in a particular group, use the following command:

yum group info glob_expression…

 ~]$ yum group info LibreOffice
Loaded plugins: langpacks, product-id, subscription-manager

Group: LibreOffice
 Group-Id: libreoffice
 Description: LibreOffice Productivity Suite
 Mandatory Packages:
 =libreoffice-calc
  libreoffice-draw
 -libreoffice-emailmerge
  libreoffice-graphicfilter
 =libreoffice-impress
 =libreoffice-math
 =libreoffice-writer
 +libreoffice-xsltfilter
 Optional Packages:
  libreoffice-base
  libreoffice-pyuno

As you can see in the above example, the packages included in the package group can have different states that are marked with the following symbols:

These distinctions take place only when the group_command configuration parameter is set to objects, which is the default setting. Set this parameter to a different value if you do not want yum to track if a package was installed as a part of the group or separately, which will make "no symbol" packages equivalent to "=" packages.

You can alter the above package states using the yum group mark command. For example, yum group mark packages marks any given installed packages as members of a specified group. To avoid installation of new packages on group update, use yum group mark blacklist. See the yum(8) man page for more information on capabilities of yum group mark.

Each package group has a name and a group ID (groupid). To list the names of all package groups, and their group IDs, which are displayed in parentheses, type:

yum group list ids

~]$ yum group list ids kde\*
Available environment groups:
  KDE Plasma Workspaces (kde-desktop-environment)
Done

~]$ yum group list hidden ids kde\*
Loaded plugins: product-id, subscription-manager
Available Groups:
  KDE (kde-desktop)
Done

You can install a package group by passing its full group name, without the groupid part, to the group install command. As root, type:

yum group install "group name"

You can also install by groupid. As root, execute the following command:

yum group install groupid

You can pass the groupid or quoted group name to the install command if you prepend it with an @ symbol, which tells yum that you want to perform group install. As root, type:

yum install @group

Replace group with the groupid or quoted group name. The same logic applies to environmental groups:

yum install @^group

~]# yum group install "KDE Desktop"
~]# yum group install kde-desktop
~]# yum install @"KDE Desktop"
~]# yum install @kde-desktop

You can remove a package group using syntax similar to the install syntax, with use of either name of the package group or its id. As root, type:

yum group remove group_name

yum group remove groupid

Also, you can pass the groupid or quoted name to the remove command if you prepend it with an @-symbol, which tells yum that you want to perform group remove. As root, type:

yum remove @group

Replace group with the groupid or quoted group name. Similarly, you can replace an environmental group:

yum remove @^group

~]# yum group remove "KDE Desktop"
~]# yum group remove kde-desktop
~]# yum remove @"KDE Desktop"
~]# yum remove @kde-desktop

To display a list of the twenty most recent transactions, as root, either run yum history with no additional arguments, or type the following at a shell prompt:

yum history list

To display all transactions, add the all keyword:

yum history list all

To display only transactions in a given range, use the command in the following form:

yum history list start_id..end_id

You can also list only transactions regarding a particular package or packages. To do so, use the command with a package name or a glob expression:

yum history list glob_expression…

~]# yum history list 1..5
Loaded plugins: langpacks, product-id, subscription-manager
ID   | Login user        | Date and time  | Action(s)   | Altered
-------------------------------------------------------------------------------
   5 | User <user>       | 2013-07-29 15:33 | Install    |  1
   4 | User <user>       | 2013-07-21 15:10 | Install    |  1
   3 | User <user>       | 2013-07-16 15:27 | I, U      |  73
   2 | System <unset>      | 2013-07-16 15:19 | Update     |  1
   1 | System <unset>      | 2013-07-16 14:38 | Install    | 1106
history list

All forms of the yum history list command produce tabular output with each row consisting of the following columns:

To synchronize the rpmdb or yumdb database contents for any installed package with the currently used rpmdb or yumdb database, type the following:

yum history sync

To display some overall statistics about the currently used history database use the following command:

yum history stats

~]# yum history stats
Loaded plugins: langpacks, product-id, subscription-manager
File    : //var/lib/yum/history/history-2012-08-15.sqlite
Size    : 2,766,848
Transactions: 41
Begin time : Wed Aug 15 16:18:25 2012
End time  : Wed Feb 27 14:52:30 2013
Counts   :
 NEVRAC : 2,204
 NEVRA : 2,204
 NA   : 1,759
 NEVR  : 2,204
 rpm DB : 2,204
 yum DB : 2,204
history stats

Yum also enables you to display a summary of all past transactions. To do so, run the command in the following form as root:

yum history summary

To display only transactions in a given range, type:

yum history summary start_id..end_id

Similarly to the yum history list command, you can also display a summary of transactions regarding a certain package or packages by supplying a package name or a glob expression:

yum history summary glob_expression…

~]# yum history summary 1..5
Loaded plugins: langpacks, product-id, subscription-manager
Login user         | Time        | Action(s)    | Altered
-------------------------------------------------------------------------------
Jaromir ... <jhradilek>  | Last day      | Install     |    1
Jaromir ... <jhradilek>  | Last week      | Install     |    1
Jaromir ... <jhradilek>  | Last 2 weeks    | I, U       |    73
System <unset>       | Last 2 weeks    | I, U       |   1107
history summary

All forms of the yum history summary command produce simplified tabular output similar to the output of yum history list.

As shown above, both yum history list and yum history summary are oriented towards transactions, and although they allow you to display only transactions related to a given package or packages, they lack important details, such as package versions. To list transactions from the perspective of a package, run the following command as root:

yum history package-list glob_expression…

~]# yum history package-list subscription-manager\*
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
ID   | Action(s)   | Package
-------------------------------------------------------------------------------
   2 | Updated    | subscription-manager-1.13.22-1.el7.x86_64     EE
   2 | Update     |           1.15.9-15.el7.x86_64     EE
   2 | Obsoleted   | subscription-manager-firstboot-1.13.22-1.el7.x86_64 EE
   2 | Updated    | subscription-manager-gui-1.13.22-1.el7.x86_64   EE
   2 | Update     |             1.15.9-15.el7.x86_64   EE
   2 | Obsoleting   | subscription-manager-initial-setup-addon-1.15.9-15.el7.x86_64 EE
   1 | Install    | subscription-manager-1.13.22-1.el7.x86_64
   1 | Install    | subscription-manager-firstboot-1.13.22-1.el7.x86_64
   1 | Install    | subscription-manager-gui-1.13.22-1.el7.x86_64
history package-list

To display the summary of a single transaction, as root, use the yum history summary command in the following form:

yum history summary id

Here, id stands for the ID of the transaction.

To examine a particular transaction or transactions in more detail, run the following command as root:

yum history info id…

The id argument is optional and when you omit it, yum automatically uses the last transaction. Note that when specifying more than one transaction, you can also use a range:

yum history info start_id..end_id

~]# yum history info 4..5
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Transaction ID : 4..5
Begin time   : Mon Dec 7 16:51:07 2015
Begin rpmdb  : 1252:d2b62b7b5768e855723954852fd7e55f641fbad9
End time    :      17:18:49 2015 (27 minutes)
End rpmdb   : 1253:cf8449dc4c53fc0cbc0a4c48e496a6c50f3d43c5
User      : Maxim Svistunov <msvistun>
Return-Code  : Success
Command Line  : install tigervnc-server.x86_64
Command Line  : reinstall tigervnc-server
Transaction performed with:
  Installed   rpm-4.11.3-17.el7.x86_64         @rhel-7-server-rpms
  Installed   subscription-manager-1.15.9-15.el7.x86_64 @rhel-7-server-rpms
  Installed   yum-3.4.3-132.el7.noarch         @rhel-7-server-rpms
Packages Altered:
  Reinstall tigervnc-server-1.3.1-3.el7.x86_64 @rhel-7-server-rpms
history info

You can also view additional information, such as what configuration options were used at the time of the transaction, or from what repository and why were certain packages installed. To determine what additional information is available for a certain transaction, type the following at a shell prompt as root:

yum history addon-info id

Similarly to yum history info, when no id is provided, yum automatically uses the latest transaction. Another way to refer to the latest transaction is to use the last keyword:

yum history addon-info last

~]# yum history addon-info 4
Loaded plugins: langpacks, product-id, subscription-manager
Transaction ID: 4
Available additional history information:
 config-main
 config-repos
 saved_tx

history addon-info

In the output of the yum history addon-info command, three types of information are available:

To display a selected type of additional information, run the following command as root:

yum history addon-info id information

Apart from reviewing the transaction history, the yum history command provides means to revert or repeat a selected transaction. To revert a transaction, type the following at a shell prompt as root:

yum history undo id

To repeat a particular transaction, as root, run the following command:

yum history redo id

Both commands also accept the last keyword to undo or repeat the latest transaction.

Note that both yum history undo and yum history redo commands only revert or repeat the steps that were performed during a transaction. If the transaction installed a new package, the yum history undo command will uninstall it, and if the transaction uninstalled a package the command will again install it. This command also attempts to downgrade all updated packages to their previous version, if these older packages are still available.

When managing several identical systems, yum also enables you to perform a transaction on one of them, store the transaction details in a file, and after a period of testing, repeat the same transaction on the remaining systems as well. To store the transaction details to a file, type the following at a shell prompt as root:

yum -q history addon-info id saved_tx > file_name

Once you copy this file to the target system, you can repeat the transaction by using the following command as root:

yum load-transaction file_name

You can configure load-transaction to ignore missing packages or rpmdb version. For more information on these configuration options see the yum.conf(5) man page.

Yum stores the transaction history in a single SQLite database file. To start new transaction history, run the following command as root:

yum history new

This will create a new, empty database file in the /var/lib/yum/history/ directory. The old transaction history will be kept, but will not be accessible as long as a newer database file is present in the directory.

The /etc/yum.conf configuration file contains exactly one [main] section, and while some of the key-value pairs in this section affect how yum operates, others affect how yum treats repositories.

You can add many additional options under the [main] section heading in /etc/yum.conf.

A sample /etc/yum.conf configuration file can look like this:

[main]
cachedir=/var/cache/yum/$basearch/$releasever
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
exactarch=1
obsoletes=1
gpgcheck=1
plugins=1
installonly_limit=3

[comments abridged]

# PUT YOUR REPOS HERE OR IN separate files named file.repo
# in /etc/yum.repos.d

The following are the most commonly used options in the [main] section:

For a complete list of available [main] options, see the [main] OPTIONS section of the yum.conf(5) manual page.

The [repository] sections, where repository is a unique repository ID such as my_personal_repo (spaces are not permitted), allow you to define individual yum repositories. To avoid conflicts, custom repositories should not use names used by Red Hat repositories.

The following is a bare minimum example of the form a [repository] section takes:

[repository]
name=repository_name
baseurl=repository_url

Every [repository] section must contain the following directives:

Other useful [repository] directive are:

Many more [repository] options exist, part of them have the same form and function as certain [main] options. For a complete list, see the [repository] OPTIONS section of the yum.conf(5) manual page.

#
# Red Hat Repositories
# Managed by (rhsm) subscription-manager
#

[red-hat-enterprise-linux-scalable-file-system-for-rhel-6-entitlement-rpms]
name = Red Hat Enterprise Linux Scalable File System (for RHEL 6 Entitlement) (RPMs)
baseurl = https://cdn.redhat.com/content/dist/rhel/entitlement-6/releases/$releasever/$basearch/scalablefilesystem/os
enabled = 1
gpgcheck = 1
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
sslverify = 1
sslcacert = /etc/rhsm/ca/redhat-uep.pem
sslclientkey = /etc/pki/entitlement/key.pem
sslclientcert = /etc/pki/entitlement/11300387955690106.pem

[red-hat-enterprise-linux-scalable-file-system-for-rhel-6-entitlement-source-rpms]
name = Red Hat Enterprise Linux Scalable File System (for RHEL 6 Entitlement) (Source RPMs)
baseurl = https://cdn.redhat.com/content/dist/rhel/entitlement-6/releases/$releasever/$basearch/scalablefilesystem/source/SRPMS
enabled = 0
gpgcheck = 1
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
sslverify = 1
sslcacert = /etc/rhsm/ca/redhat-uep.pem
sslclientkey = /etc/pki/entitlement/key.pem
sslclientcert = /etc/pki/entitlement/11300387955690106.pem

[red-hat-enterprise-linux-scalable-file-system-for-rhel-6-entitlement-debug-rpms]
name = Red Hat Enterprise Linux Scalable File System (for RHEL 6 Entitlement) (Debug RPMs)
baseurl = https://cdn.redhat.com/content/dist/rhel/entitlement-6/releases/$releasever/$basearch/scalablefilesystem/debug
enabled = 0
gpgcheck = 1
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
sslverify = 1
sslcacert = /etc/rhsm/ca/redhat-uep.pem
sslclientkey = /etc/pki/entitlement/key.pem
sslclientcert = /etc/pki/entitlement/11300387955690106.pem

You can use and reference the following built-in variables in yum commands and in all yum configuration files (that is, /etc/yum.conf and all .repo files in the /etc/yum.repos.d/ directory):

To define a custom variable or to override the value of an existing one, create a file with the same name as the variable (without the "$" sign) in the /etc/yum/vars/ directory, and add the desired value on its first line.

For example, repository descriptions often include the operating system name. To define a new variable called $osname, create a new file with "Red Hat Enterprise Linux" on the first line and save it as /etc/yum/vars/osname:

~]# echo "Red Hat Enterprise Linux 7" > /etc/yum/vars/osname

Instead of "Red Hat Enterprise Linux 7", you can now use the following in the .repo files:

name=$osname $releasever

To display the current values of global yum options (that is, the options specified in the [main] section of the /etc/yum.conf file), execute the yum-config-manager command with no command-line options:

yum-config-manager

To list the content of a different configuration section or sections, use the command in the following form:

yum-config-manager section…

You can also use a glob expression to display the configuration of all matching sections:

yum-config-manager glob_expression…

~]$ yum-config-manager main \*
Loaded plugins: langpacks, product-id, subscription-manager
================================== main ===================================
[main]
alwaysprompt = True
assumeyes = False
bandwith = 0
bugtracker_url = https://bugzilla.redhat.com/enter_bug.cgi?product=Red%20Hat%20Enterprise%20Linux%206&component=yum
cache = 0
[output truncated]

Section 9.5.2, “Setting [repository] Options” describes various options you can use to define a yum repository. This section explains how to add, enable, and disable a repository by using the yum-config-manager command.

Yum repositories commonly provide their own .repo file. To add such a repository to your system and enable it, run the following command as root:

yum-config-manager --add-repo repository_url

…where repository_url is a link to the .repo file.

~]# yum-config-manager --add-repo http://www.example.com/example.repo
Loaded plugins: langpacks, product-id, subscription-manager
adding repo from: http://www.example.com/example.repo
grabbing file http://www.example.com/example.repo to /etc/yum.repos.d/example.repo
example.repo                       | 413 B   00:00
repo saved to /etc/yum.repos.d/example.repo

yum-config-manager --enable repository…

…where repository is the unique repository ID (use yum repolist all to list available repository IDs). Alternatively, you can use a glob expression to enable all matching repositories:

yum-config-manager --enable glob_expression…

~]# yum-config-manager --enable example\*
Loaded plugins: langpacks, product-id, subscription-manager
============================== repo: example ==============================
[example]
bandwidth = 0
base_persistdir = /var/lib/yum/repos/x86_64/7Server
baseurl = http://www.example.com/repo/7Server/x86_64/
cache = 0
cachedir = /var/cache/yum/x86_64/7Server/example
[output truncated]

~]# yum-config-manager --enable \*
Loaded plugins: langpacks, product-id, subscription-manager
============================== repo: example ==============================
[example]
bandwidth = 0
base_persistdir = /var/lib/yum/repos/x86_64/7Server
baseurl = http://www.example.com/repo/7Server/x86_64/
cache = 0
cachedir = /var/cache/yum/x86_64/7Server/example
[output truncated]

When successful, the yum-config-manager --enable command displays the current repository configuration.

yum-config-manager --disable repository…

…where repository is the unique repository ID (use yum repolist all to list available repository IDs). Similarly to yum-config-manager --enable, you can use a glob expression to disable all matching repositories at the same time:

yum-config-manager --disable glob_expression…

~]# yum-config-manager --disable \*
Loaded plugins: langpacks, product-id, subscription-manager
============================== repo: example ==============================
[example]
bandwidth = 0
base_persistdir = /var/lib/yum/repos/x86_64/7Server
baseurl = http://www.example.com/repo/7Server/x86_64/
cache = 0
cachedir = /var/cache/yum/x86_64/7Server/example
[output truncated]

When successful, the yum-config-manager --disable command displays the current configuration.

To set up a yum repository:

The Optional and Supplementary subscription channels provide additional software packages for Red Hat Enterprise Linux that cover open source licensed software (in the Optional channel) and proprietary licensed software (in the Supplementary channel).

Before subscribing to the Optional and Supplementary channels see the Scope of Coverage Details. If you decide to install packages from these channels, follow the steps documented in the article called How to access Optional and Supplementary channels, and -devel packages using Red Hat Subscription Manager (RHSM)? on the Red Hat Customer Portal.

To enable yum plug-ins, ensure that a line beginning with plugins= is present in the [main] section of /etc/yum.conf, and that its value is 1:

plugins=1

You can disable all plug-ins by changing this line to plugins=0.

Every installed plug-in has its own configuration file in the /etc/yum/pluginconf.d/ directory. You can set plug-in specific options in these files. For example, here is the aliases plug-in’s aliases.conf configuration file:

[main]
enabled=1

Similar to the /etc/yum.conf file, the plug-in configuration files always contain a [main] section where the enabled= option controls whether the plug-in is enabled when you run yum commands. If this option is missing, you can add it manually to the file.

If you disable all plug-ins by setting enabled=0 in /etc/yum.conf, then all plug-ins are disabled regardless of whether they are enabled in their individual configuration files.

If you merely want to disable all yum plug-ins for a single yum command, use the --noplugins option.

If you want to disable one or more yum plug-ins for a single yum command, add the --disableplugin=plugin_name option to the command. For example, to disable the aliases plug-in while updating a system, type:

~]# yum update --disableplugin=aliases

The plug-in names you provide to the --disableplugin= option are the same names listed after the Loaded plugins line in the output of any yum command. You can disable multiple plug-ins by separating their names with commas. In addition, you can match multiple plug-in names or shorten long ones by using glob expressions:

~]# yum update --disableplugin=aliases,lang*

Yum plug-ins usually adhere to the yum-plugin-plugin_name package-naming convention, but not always: the package which provides the kabi plug-in is named kabi-yum-plugins, for example. You can install a yum plug-in in the same way you install other packages. For instance, to install the yum-aliases plug-in, type the following at a shell prompt:

~]# yum install yum-plugin-aliases

The following list provides descriptions and usage instructions for several useful yum plug-ins. Plug-ins are listed by names, brackets contain the name of the package.

To enable automatic installation of downloaded updates, edit the daily configuration file for daily installation or the hourly configuration file for hourly installation by setting the apply_updates option as follows:

apply_updates = yes

By default, the yum-cron service uses cron to send emails containing an output of the executed command. This email is sent according to cron configuration, typically to the local superuser and stored in the /var/spool/mail/root file.

You can use specific email configuration different from the settings which affect all cron jobs. However, this email configuration does not support TLS and overall email built-in logic is very basic.

To enable yum-cron built-in email notifications:

The yum-cron does not support specific configuration of repositories. As a workaround for enabling or disabling specific repositories for yum-cron but not for yum in general follow the steps bellow:

To test yum-cron settings without waiting for the next scheduled yum-cron task:

The yum-cron messages cannot be entirely disabled, but can be limited to messages with critical priority only. To limit the messages:

The yum-cron service does not support any configuration option for removing packages similar to the yum clean all command. To clean packages automatically, you can create a cron job as an executable shell script: