YUM Package Manager
YUM (originally known as Yellowdog Updater Modified) is a command line package manager for use with rpm based Linux distributions. Yum was originally created to manage Red Hat Enterprise Linux systems, however many other popular distributions now use this tool as the command line package manager of choice. Distributions such as CentOS and Fedora use Yum. However, yum is being phased out and being replaced with the "DNF" package manager. Yum offers a simple to use interface for the updating, and removal of packages. Yum also handles all dependencies and pre-requisites.
YUM Command Examples
The most common functions used within Yum are the "install", "erase", "update", "list" and "search". However, yum has many more functions that can be carried out. Below are some of the common uses for yum:
Display YUM Version
Basic Syntax: yum --version
# yum --version
4.2.23
Installed: dnf-0:4.2.23-4.el8.noarch at Mon 05 Apr 2021 13:25:49 GMT
Built : CentOS Buildsys at Tue 04 Aug 2020 18:52:03 GMT
Installed: rpm-0:4.14.3-4.el8.x86_64 at Mon 05 Apr 2021 13:25:13 GMT
Built : CentOS Buildsys at Tue 21 Jul 2020 17:36:08 GMT
The above command is used to display the currently installed version of the yum package manager.
Yum is now a symbolic link that points to "dnf". This example was taken from a CentOS 8 system.Displaying Repositories - yum repolist
Basic Syntax: yum repolist
# yum repolist
repo id repo name
appstream CentOS Linux 8 - AppStream
baseos CentOS Linux 8 - BaseOS
extras CentOS Linux 8 - Extras
The command "yum repolist" will display all enabled repositories. You may pass an additional parameter of "all" to display enabled and disabled repositories.
# yum repolist all
repo id repo name status
appstream CentOS Linux 8 - AppStream enabled
appstream-source CentOS Linux 8 - AppStream - Source disabled
baseos CentOS Linux 8 - BaseOS enabled
baseos-source CentOS Linux 8 - BaseOS - Source disabled
cr CentOS Linux 8 - ContinuousRelease disabled
debuginfo CentOS Linux 8 - Debuginfo disabled
devel CentOS Linux 8 - Devel WARNING! FOR BUILDROOT USE ONLY disabled
extras CentOS Linux 8 - Extras enabled
extras-source CentOS Linux 8 - Extras - Source disabled
fasttrack CentOS Linux 8 - FastTrack disabled
ha CentOS Linux 8 - HighAvailability disabled
media-appstream CentOS Linux 8 - Media - AppStream disabled
media-baseos CentOS Linux 8 - Media - BaseOS disabled
plus CentOS Linux 8 - Plus disabled
plus-source CentOS Linux 8 - Plus - Source disabled
powertools CentOS Linux 8 - PowerTools disabled
Yum installing a package
Basic Syntax: yum install package-name
# yum install nmap
Last metadata expiration check: 0:05:32 ago on Thu 06 May 2021 19:08:16 BST.
Dependencies resolved.
================================================================================
Package Architecture Version Repository Size
================================================================================
Installing:
nmap x86_64 2:7.70-5.el8 appstream 5.8 M
Installing dependencies:
nmap-ncat x86_64 2:7.70-5.el8 appstream 237 k
Transaction Summary
================================================================================
Install 2 Packages
Total download size: 6.1 M
Installed size: 25 M
Is this ok [y/N]: y
If the package is available within our repositories, then we are prompted to reply "y/N" to confirm our actions. In this case we are going to reply "y" to install the package called "nmap" and any dependencies.
Downloading Packages:
(1/2): nmap-ncat-7.70-5.el8.x86_64.rpm 1.3 MB/s | 237 kB 00:00
(2/2): nmap-7.70-5.el8.x86_64.rpm 4.9 MB/s | 5.8 MB 00:01
--------------------------------------------------------------------------------
Total 4.0 MB/s | 6.1 MB 00:01
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : nmap-ncat-2:7.70-5.el8.x86_64 1/2
Running scriptlet: nmap-ncat-2:7.70-5.el8.x86_64 1/2
Installing : nmap-2:7.70-5.el8.x86_64 2/2
Running scriptlet: nmap-2:7.70-5.el8.x86_64 2/2
Verifying : nmap-2:7.70-5.el8.x86_64 1/2
Verifying : nmap-ncat-2:7.70-5.el8.x86_64 2/2
Installed:
nmap-2:7.70-5.el8.x86_64 nmap-ncat-2:7.70-5.el8.x86_64
Complete!
As you can see from the above, the requested package has been installed successfully.
Yum Removing a package
Basic Syntax: yum erase package-name or yum remove package-name
# yum remove nmap
Dependencies resolved.
================================================================================
Package Architecture Version Repository Size
================================================================================
Removing:
nmap x86_64 2:7.70-5.el8 @appstream 24 M
Removing unused dependencies:
nmap-ncat x86_64 2:7.70-5.el8 @appstream 681 k
Transaction Summary
================================================================================
Remove 2 Packages
Freed space: 25 M
Is this ok [y/N]: y
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Erasing : nmap-2:7.70-5.el8.x86_64 1/2
Erasing : nmap-ncat-2:7.70-5.el8.x86_64 2/2
Running scriptlet: nmap-ncat-2:7.70-5.el8.x86_64 2/2
Verifying : nmap-2:7.70-5.el8.x86_64 1/2
Verifying : nmap-ncat-2:7.70-5.el8.x86_64 2/2
Removed:
nmap-2:7.70-5.el8.x86_64 nmap-ncat-2:7.70-5.el8.x86_64
Complete!
In this example we removed the package "nmap" with the command "yum remove nmap". You can also use the "erase" option to achieve the same result.
Listing Installed Packages
Basic Syntax: yum list installed
# yum list installed
Installed Packages
NetworkManager.x86_64 1:1.26.0-12.el8_3 @baseos
NetworkManager-libnm.x86_64 1:1.26.0-12.el8_3 @baseos
NetworkManager-team.x86_64 1:1.26.0-12.el8_3 @baseos
NetworkManager-tui.x86_64 1:1.26.0-12.el8_3 @baseos
acl.x86_64 2.2.53-1.el8 @anaconda
adcli.x86_64 0.8.2-7.el8 @anaconda
at.x86_64 3.1.20-11.el8 @anaconda
attr.x86_64 2.4.48-3.el8 @anaconda
audit.x86_64 3.0-0.17.20191104git1c2f876.el8 @anaconda
audit-libs.x86_64 3.0-0.17.20191104git1c2f876.el8 @anaconda
authselect.x86_64 1.2.1-2.el8 @anaconda
In the above example we issued the "yum list installed" command. This command will display any packages that have been installed on your Linux system. However, the output returned will be considerable in size. Above is a small section from the output of this command.
If you know the name of the package you want to check, you can specify this using the syntax: "yum list installed package-name". For example, if we wanted to check for a package called "bzip2", we would issue the following command
yum list installed bzip2
# yum list installed bzip2
Installed Packages
bzip2.x86_64 1.0.6-26.el8 @anaconda
Display package information
To display information about a package, the "info" parameter can be passed. As an example, if we wanted to know more information about the package "bzip2", we would issue the following command:
yum info bzip2
From the above,we can see that the package "bzip2" is listed as an "Installed Package". Basic Syntax: yum check-update The "yum check-update" command can be run to check for any updates to packages on your system. Any updates that are available will then be displayed. You may also use the command "yum list updates". Any updates that are available to your system will be displayed. Basic Syntax: yum list package In the above example we were checking for any available updates for the package called "openssl". The relevant information is displayed under the headings "Available Packages" and "Available Packages". In the above example we can see that a newer version of the openssl package is available. To update the package, you would issue the command: "yum update openssl". Basic Syntax: yum update In the above example we are installing any updates that are available for any installed packages on our system. In the above example, no updates were found as the system is upto-date. If packages are available, they will be displayed as number of packages to be installed along with the number of packages to be upgraded. To search for a package, the command "yum search pattern can be used. Any packages that match the pattern will be displayed. Basic Syntax: yum search pattern In the above example we searched for any packages that contained the string "bash". This option is useful if you do not know the full name of a package. Basic Syntax: yum provides package-file> The above command displays which package provides the specified file. As an example, If you wanted to find which package provides the utility "netstat, then you would issue the following command: In the above example, we used the "yum provides" command to identify the package that would install the "netstat" utility. Once the package was identified, we then installed the package making "netstat" available. Basic Syntax: yum reinstall package name The "yum reinstall" command is used to reinstall the specified package. Basic Syntax: yum downgrade package-name The "yum downgrade" command is used to downgrade the specified packages to the highest of all known lower versions if possible. To establish the current version of a package you can use the command "yum list package-name". Be very careful when downgrading packages as they can impact the stability of your system. Always check the output first to see exactly what is going to be downgraded. You should never attempt to rollback the following packages: "dbus, kernel, glibc and selinux-policy". Example: Many packages on Linux systems are bundled together as a group of packages. So instead of installing a list of individual packages, you can specify a group of packages to install. Below is a list of available groups on a standard CentOS 8 installation. These groups can be displayed by issuing the following command": yum grouplist If we wanted to install a Graphical desktop, we could issue the command: yum group install "Server with GUI". Notice, you have to include double quotes around the group name if there are spaces within the name of the group. Below is a small extract of the typical output you would see from this command: If you did want to install the Graphical interface for your server, you would also need to change the default target level by issuing the following command: The above command instructs your system to boot into graphical mode. The command used to remove a group package is: yum groupremove "group package name" Basic Syntax: yum history The "yum history" command is used to display transactions that have happened in the past. This command enables you to view the last updates or packages that have been installed to your system. The above output identifies what packages were installed along with a date and time. For a full list of all packages, we need to use the command "yum history info ID" command To view the history of any transaction, issue the command: "yum history info ID". Replace the "ID" with the number displayed in the ID column. From the above, we can see that two packages were upgraded. For a full list of all available commands and options, issue the command: "yum --help".
# yum info bzip2
Last metadata expiration check: 0:24:10 ago on Thu 06 May 2021 19:08:16 BST.
Installed Packages
Name : bzip2
Version : 1.0.6
Release : 26.el8
Architecture : x86_64
Size : 91 k
Source : bzip2-1.0.6-26.el8.src.rpm
Repository : @System
From repo : anaconda
Summary : A file compression utility
URL : http://www.bzip.org/
License : BSD
Description : Bzip2 is a freely available, patent-free, high quality data
: compressor. Bzip2 compresses files to within 10 to 15 percent of
: the capabilities of the best techniques available. However,
: bzip2 has the added benefit of being approximately two times
: faster at compression and six times faster at decompression than
: those techniques. Bzip2 is not the fastest compression utility,
: but it does strike a balance between speed and compression
: capability.
:
: Install bzip2 if you need a compression utility.
Checking for Updates
Check for updates for specific package
# yum list openssl
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.vooservers.com
* epel: mirrors.ukfast.co.uk
* extras: repo.bigstepcloud.com
* updates: mirror.ukhost4u.com
Installed Packages
openssl.x86_64 1.0.1e-42.el6 @anaconda-CentOS-201508042137.x86_64/6.7
Available Packages
openssl.i686 1.0.1e-42.el6_7.2 updates
openssl.x86_64 1.0.1e-42.el6_7.2 updates
Update all Installed Packages
# yum update
Last metadata expiration check: 0:58:44 ago on Thu 06 May 2021 19:08:16 BST.
Dependencies resolved.
Nothing to do.
Complete!
Search for a package
# yum search bash
Last metadata expiration check: 1:02:22 ago on Thu 06 May 2021 19:08:16 BST.
========================== Name Exactly Matched: bash ==========================
bash.x86_64 : The GNU Bourne Again shell
========================= Name & Summary Matched: bash =========================
bash-completion.noarch : Programmable completion for Bash
bash-doc.x86_64 : Documentation files for bash
libguestfs-bash-completion.noarch : Bash tab-completion scripts for libguestfs
: tools
libvirt-bash-completion.x86_64 : Bash completion script
nbdkit-bash-completion.noarch : Bash tab-completion for nbdkit
pcp-pmda-bash.x86_64 : Performance Co-Pilot (PCP) metrics for the Bash shell
============================ Summary Matched: bash =============================
python3-argcomplete.noarch : Bash tab completion for argparse
yum provides
"yum provides netstat"
# yum provides netstat
Last metadata expiration check: 1:08:39 ago on Thu 06 May 2021 19:08:16 BST.
net-tools-2.0-0.52.20160912git.el8.x86_64 : Basic networking tools
Repo : baseos
Matched from:
Filename : /usr/bin/netstat
# yum install net-tools
Last metadata expiration check: 1:08:54 ago on Thu 06 May 2021 19:08:16 BST.
Dependencies resolved.
================================================================================
Package Architecture Version Repository Size
================================================================================
Installing:
net-tools x86_64 2.0-0.52.20160912git.el8 baseos 322 k
Transaction Summary
================================================================================
Install 1 Package
Total download size: 322 k
Installed size: 942 k
Is this ok [y/N]: y
Downloading Packages:
net-tools-2.0-0.52.20160912git.el8.x86_64.rpm 1.8 MB/s | 322 kB 00:00
--------------------------------------------------------------------------------
Total 524 kB/s | 322 kB 00:00
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : net-tools-2.0-0.52.20160912git.el8.x86_64 1/1
Running scriptlet: net-tools-2.0-0.52.20160912git.el8.x86_64 1/1
Verifying : net-tools-2.0-0.52.20160912git.el8.x86_64 1/1
Installed:
net-tools-2.0-0.52.20160912git.el8.x86_64
Complete!
Reinstalling a Package
# yum reinstall net-tools
Last metadata expiration check: 1:13:20 ago on Thu 06 May 2021 19:08:16 BST.
Dependencies resolved.
================================================================================
Package Architecture Version Repository Size
================================================================================
Reinstalling:
net-tools x86_64 2.0-0.52.20160912git.el8 baseos 322 k
Transaction Summary
================================================================================
Total download size: 322 k
Installed size: 942 k
Is this ok [y/N]: y
Downloading Packages:
net-tools-2.0-0.52.20160912git.el8.x86_64.rpm 1.3 MB/s | 322 kB 00:00
--------------------------------------------------------------------------------
Total 853 kB/s | 322 kB 00:00
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Running scriptlet: net-tools-2.0-0.52.20160912git.el8.x86_64 1/1
Reinstalling : net-tools-2.0-0.52.20160912git.el8.x86_64 1/2
Running scriptlet: net-tools-2.0-0.52.20160912git.el8.x86_64 1/2
Cleanup : net-tools-2.0-0.52.20160912git.el8.x86_64 2/2
Running scriptlet: net-tools-2.0-0.52.20160912git.el8.x86_64 2/2
Verifying : net-tools-2.0-0.52.20160912git.el8.x86_64 1/2
Verifying : net-tools-2.0-0.52.20160912git.el8.x86_64 2/2
Reinstalled:
net-tools-2.0-0.52.20160912git.el8.x86_64
Complete!
Downgrading a Package
# yum list openssl.x86_64
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.vooservers.com
* epel: mirrors.ukfast.co.uk
* extras: repo.bigstepcloud.com
* updates: mirror.ukhost4u.com
Installed Packages
openssl.x86_64 1.0.1e-42.el6_7.2 @updates
# yum downgrade openssl.x86_64
Loaded plugins: fastestmirror
Setting up Downgrade Process
Loading mirror speeds from cached hostfile
* base: mirrors.vooservers.com
* epel: mirrors.ukfast.co.uk
* extras: repo.bigstepcloud.com
* updates: mirror.ukhost4u.com
Resolving Dependencies
--> Running transaction check
---> Package openssl.x86_64 0:1.0.1e-42.el6_7.1 will be a downgrade
---> Package openssl.x86_64 0:1.0.1e-42.el6_7.2 will be erased
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Downgrading:
openssl x86_64 1.0.1e-42.el6_7.1 updates 1.5 M
Transaction Summary
================================================================================
Downgrade 1 Package(s)
Total download size: 1.5 M
Is this ok [y/N]: y
Downloading Packages:
openssl-1.0.1e-42.el6_7.1.x86_64.rpm | 1.5 MB 00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : openssl-1.0.1e-42.el6_7.1.x86_64 1/2
Cleanup : openssl-1.0.1e-42.el6_7.2.x86_64 2/2
Verifying : openssl-1.0.1e-42.el6_7.1.x86_64 1/2
Verifying : openssl-1.0.1e-42.el6_7.2.x86_64 2/2
Removed:
openssl.x86_64 0:1.0.1e-42.el6_7.2
Installed:
openssl.x86_64 0:1.0.1e-42.el6_7.1
Complete!
List available groups
# yum grouplist
Last metadata expiration check: 1:28:25 ago on Thu 06 May 2021 19:08:16 BST.
Available Environment Groups:
Server with GUI
Server
Workstation
Virtualization Host
Custom Operating System
Installed Environment Groups:
Minimal Install
Available Groups:
Container Management
.NET Core Development
RPM Development Tools
Development Tools
Graphical Administration Tools
Headless Management
Legacy UNIX Compatibility
Network Servers
Scientific Support
Security Tools
Smart Card Support
System Tools
Installing Environment Groups:
Server with GUI
Installing Groups:
base-x
Container Management
Core
Fonts
GNOME
Guest Desktop Agents
Hardware Monitoring Utilities
Hardware Support
Headless Management
Input Methods
Internet Browser
Multimedia
Common NetworkManager submodules
Printing Client
Server product core
Standard
Transaction Summary
================================================================================
Install 879 Packages
Total download size: 833 M
Installed size: 2.3 G
Is this ok [y/N]:
systemctl set-default graphical
Remove a group package
Display Transaction History
# yum history
ID | Command line | Date and time | Action(s) | Altered
--------------------------------------------------------------------------------
11 | reinstall net-tools | 2021-05-06 20:21 | R | 2
10 | install net-tools | 2021-05-06 20:17 | Install | 1
9 | remove net-tools | 2021-05-06 20:16 | Removed | 1
8 | remove nmap | 2021-05-06 19:21 | Removed | 2
7 | install nmap | 2021-05-06 19:16 | Install | 2
6 | update | 2021-05-06 19:12 | Upgrade | 2
5 | install pcp-system-tools | 2021-04-25 11:11 | Install | 16
4 | update | 2021-04-25 11:05 | I, U | 77 EE
3 | install iptraf-ng | 2021-04-24 19:32 | Install | 1
2 | install wget | 2021-04-24 13:48 | Install | 1
1 | | 2021-04-05 14:23 | Install | 447 EE
Yum History Info
# yum history info 6
Transaction ID : 6
Begin time : Thu 06 May 2021 19:12:51 BST
Begin rpmdb : 470:d7376df017ace90b964fedfacdeb043a79bd3363
End time : Thu 06 May 2021 19:13:34 BST (43 seconds)
End rpmdb : 470:90a69471d69beece85331af7c03515de544d9166
User : John
Help with yum
