31 Yum command for Package Management in Linux

Introduction to Yum Command

Yum, the command is a package manager used to manage RPM packages in Linux servers. YUM is known as “Yellowdog Updater Modified” it has several options with arguments to search, install, remove and update the packages. They are used across only (RPM) RedHat based operating system like Fedora, Red Hat, CentOS, Oracle Linux and Scientific Linux. Now let us start to run yum command with option and arguments to perform some installations.

Adding “-y” with yum command will not prompt by asking “[y/d/N]” during installing, removing or Updating.

Related Article to YUM

Using AppStream with yum in Red Hat Enterprise Linux 8

The listing, Installing and Removing

Let start with searching for anyone of the package.

# yum search httpd

List all the packages, only specific package using its name, or list all available packages.

# yum list
# yum list httpd
# yum list available

At first, Before installing it’s a good practice to know about some information by using “info” option.

# yum info httpd

Now let us try to install two packages in a single go.

# yum install httpd nc -y

In case we may be required to re-install any package we don’t need to remove and install. Instead, we can perform a re-install.

# yum reinstall httpd -y

In some case you don’t require “nc” instead you need “telnet” this can be accomplished by using “swap” command, this will remove the nc and install the telnet.

# yum swap nc telnet -y

By running “repolist” will print only the enabled repos, to list all repository use “repolist all” this Which will print the status enabled or disabled. Even we can list only the enabled repos.

# yum repolist
# yum repolist all
# yum repolist enabled

To remove a package from the server we can use with “remove” or “erase”.

# yum remove httpd
       or
# yum erase httpd

Enabling the Yum repository

To enable anyone of repository we need to use “yum-config-manager”, In case if this command not available in your minimal installation make sure to install with “yum-utils” package.

# yum-config-manager --enable fasttrack
# yum repolist all
# yum-config-manager --disable fasttrack
# yum repolist all

Working with Yum groups

To print the “Available Environment Groups” and all available Groups.

Available environment groups: This is group consists of a group of packages define how the server needs to be built, it can be Web Server, Minimal installation or server with the graphical interface.

Available Groups: This group consists of all other groups of software like “Development Tools” or “System Administration Tools”.

# yum groups

Printing all available groups with the respective group name.

# yum grouplist

Once we know the group name we should mention the group name inside a double quote to gather info, install or remove.

# yum groupinfo "Security Tools"
# yum groupinstall "Security Tools"
# yum groupremove "Security Tools"

Checking for Update, Upgrade and Downgrade

To Check the local RPM database for any problems use the “check” option.

# yum check

Use the command check-update to do a dry run without updating any packages.

# yum check-update

Running update command will update all the packages in your server.

# yum update -y

Anyone of the specific packages needs to be upgraded we can use upgrade by following package name.

# yum upgrade httpd -y

Rollback anyone of the package to the previous version.

# yum downgrade httpd -y

Listing dependencies and finding features

While installing a package it may require several dependencies, If we need to know the dependencies use “deplist”.

# yum deplist httpd

We don’t know how the /tmp file system was created, or example “nc” command was not available in the server. To know the package name which makes available them we can use “provides” option.

# yum provides /tmp

Download RPM without installing

To download an “RPM” package without installing it. While using this command it will save the package under default location “/var/cache/yum/x86_64/7/base/packages“.

# yum install --downloadonly httpd

In some case, if we need to save under any custom location provide the destination using “–downloaddir” option.

# yum install --downloadonly --downloaddir="/root" httpd

Installing a downloaded Package

To install a downloaded package use “localinstall” option

# yum localinstall httpd-2.4.6-80.0.1.el7.x86_64.rpm

Even we can use rpm command to perform the same.

Working with Yum cache

To cache the metadata for the available repository.

# yum makecache

Whenever we are installing any packages it will not clear after the downloading and installing it. Without clearing the space it will consume more space under “/var/cache/yum/” We need to clear them using the “clean” option or manually removing them.

# yum clean packages

To clear the Yum expired caches

# yum clean expire-cache

There are a lot of caches involved in Yum like, dbcache, rpmdb, plugins, metadata and packages. We have a handy command to clear all above in a single go by running.

# yum clean all

Using Yum Shell

Yum package manager has its own Shell, running all yum command from the shell is possible. Only we need to type the options and argument as shown below. Once all actions are entred at the last type “run” to perform the actions.

# yum shell

Working with Yum History

Listing out all YUM used history. The output of this command will provide which user Installed, removed or updated some package using yum.

# yum history

1. ID of yum history output.
2. Which user performed the installation or upgrade.
3. Date and time when they have performed the installation.
4. What action they have done, Whether install, update or remove.
5. The number of packages affected during the action.

In the above screenshot of “yum history” we need to rollback by choosing any one of an ID, let us rollback ID “8“.

# yum history undo 8

There are several security options available under the yum command. This will be very helpful while we patch the servers to find and apply the right advisory and bug fixes will cover this topic in the next upcoming guide.

Using Man pages

We have covered most of the useful common day to day required commands in this article, however, if you need to read more its good to scroll through man pages using anyone of below three methods.

# yum man
# yum help
# yum --help

To know all man pages related to “yum” use

# man -k yum

This will list out all the related man pages of yum command.

That’s it we have almost covered all useful yum command and its options will cover more topics related to yum in feature posts.

Conclusion

To perform any installation using yum repository we need to be familiar with it, going through all above command with option will make sure you are good with yum command. Subscribe to our newsletter to receive updates and provide your feedback in the comment section.