Useful notes about Yum

A cheat sheet for working with the Yum (Yellowdog Updater, Modified) package manager which is used in popular Linux distributions: RedHat, CentOS, Scientific Linux (and others). To save space, command output is not shown.

Table of contents

Commands Yum Options Yum-utils package Config files Plugins Working through a proxy

display of commands and options

yum help

list of package names from the repository

yum list

list of all available packages

yum list available

list of all installed packages

yum list installed

is the specified package installed

yum list installed httpd

list of installed and available packages

yum list all

list of packages related to the kernel

yum list kernel

display information about the package

yum info httpd

list of dependencies and required packages

yum deplist httpd

find the package that contains the file

yum provides '*bin/top'

search for a package by name and description

yum search httpd
yum search yum

get information about available security updates

yum updateinfo list security

display a list of groups

yum grouplist

display the description and contents of the group

yum groupinfo 'Basic Web Server'

installing the “Basic Web Server” package group

yum groupinstall 'Basic Web Server'

deleting a group

yum groupremove 'Basic Web Server'

Check for available updates

yum check-update

list of connected repositories

yum repolist

information about a specific repository

yum repoinfo epel

information about packages in the specified repository

yum repo-pkgs epel list

install all packages from the repository

yum repo-pkgs reponame install

remove packages installed from the repository

yum repo-pkgs reponame remove

create cache

yum makecache

check local rpm database (dependencies, duplicates, obsoletes, provides options are supported)

yum check
yum check dependencies

viewing yum history (listing transactions)

yum history list

view information about a specific transaction (installed packages, installed dependencies)

yum history info 9

transaction cancellation

yum history undo 9

repeat

yum history redo 9

Additionally, you can view the log

cat /var/log/yum.log

remove cached packages

yum clean packages

remove all packages and metadata

yum clean all

install package

yum install httpd

package removal

yum remove httpd

update package

yum update httpd

update all packages

yum update

upgrade to a specific version

yum update-to

update from local directory

yum localinstall httpd.rpm

install from http

yum localinstall http://server/repo/httpd.rpm

rollback to a previous package version

yum downgrade

reinstall the package (recovering deleted files)

yum reinstall httpd

remove unnecessary packages

yum autoremove

create local repositories (createrepo is installed separately)

createrepo

install scheduled updates (yum-cron is installed separately)

yum cron

Yum Options

answer “yes” when prompted,

-y

yum update -y

answer “no” when prompted --assumeno

use Yum without plugins --noplugins

or disable a specific plugin --disableplugin=fastestmirror

enable plugins that are installed but disabled

yum -enableplugin=ps

enable disabled repository

yum update -y -enablerepo=epel

disable repository

yum update -y -disablerepo=epel

download packages but don’t install (on Centos 7 x86_64 will be downloaded to ‘/var/cache/yum/x86_64/7/base/packages/’)

yum install httpd -downloadonly

The following commands are available after installing the yum-utils package

find which repository a package is installed from

find-repos-of-install httpd

find processes whose packages are up to date and need to be restarted

need-restarting

request to repository, find out package dependencies without installing it

repoquery -requires -resolve httpd

sync yum updates repository to local repo1 directory

reposync -p repo1 -repoid=updates

check local repository for integrity

verifytree URL

complete transactions

yum-complete-transaction

install the necessary dependencies to build the RPM package

yum-builddep

manage configuration options and yum repositories

yum-config-manager

request to local yum database, display information about the package (command used, checksum, URL from which it was set, etc.)

yumdb info httpd

download rpm packages from repository

yum downloader

download src.rpm package from repository (the corresponding repository must be included, for example in ‘/etc/yum.repos.d/CentOS-Sources.repo’ in CentOS)

yumdownloader --source php

Yum configuration files and their location

• Main config file /etc/yum.conf
• directory, with configurations (for example, yum plugins) /etc/yum/
• directory containing information about repositories /etc/yum.conf.d/

Some yum.conf options:

Directory where yum stores cache and database files (default /var/cache/yum)

cachedir=/var/cache/yum/$basearch/$releasever

Specifies whether or not Yum should keep a cache of headers and packages after a successful installation. Values: 0 or 1. (default 1) keepcache=1

debug output level. Values: 1-10 (default 2) debuglevel=2

log file (default ‘/var/log/yum.log’) logfile=/var/log/yum.log

update obsolete packages obsoletes=1

package signature verification. Values: 0 or 1 (default 1) gpgcheck=1

enabling plugins. Values: 0 or 1 (default 1) plugins=1

Some useful plugins

Adds command line option to view changelog before/after updates

yum-plugin-changelog

selects faster repositories from a list of mirrors

yum-plugin-fastestmirror

adds keys, keys-info, keys-data, keys-remove commands that allow you to work with keys.

yum-plugin-keys

block specified packages from updating, yum versionlock command

yum-plugin-versionlock

adding yum verify-all, verify-multilib, verify-rpm commands to verify package checksums

yum-plugin-verify

Work Yum through a proxy server

For all users:

add to the [main] section in /etc/yum.conf

proxy='http://server:3128'

if necessary, specify a password, add

proxy_proxy_username=user
proxy_password=pass

specify proxy for individual user

export http_proxy='http://server:3128'

Read more:

man yum
man rpm