What is yum?
yum is the default package manager for RPM-based linux distributions (CentOS, Fedora, RHEL, Oracle). It’s written in python and it stands for “Yellowdog Updater, Modified”, as it was originally called “yup”, the package manager for Yellow Dog Linux. Unlike it’s debian cousin, which uses various commands for package management, yum can perform all package operations by itself.
Useful flags
Assume yes for all prompts
--y
Assume no for all prompts
--assumeno
Disable GPG verification
--nogpgcheck
Skip broken packages
Skips packages that whose dependencies can’t be resolved.
--skip-broken
Enable/Disable repository
You can dynamically enable or disable a repository for a single execution.
--disable-repo=[path]
--enable-repo=[path]
Package Management
Installing an RPM package
Installing an RPM package from remote repositories
$ sudo yum install [package-name]
Installing a local RPM package
$ sudo yum install /path/to/vim-1.2.rpm
Installing a specific version of a package
$ sudo yum install gcc-4.0
Removing an RPM package and dependencies
Removes a package and any package it depends on (provided nothing else depends on it).
$ sudo yum remove [package-name]
Note: this will only remove the binaries and libraries, any configuration files will stay intact.
Downgrade a package
This will install the package’s previous version.
$ sudo yum downgrade [package-name]
View a package’s dependencies
$ sudo yum deplist [package-name]
Listing packages
The yum list
command can take different arguments:
List all available packages from repositories
$ sudo yum list available
List installed packages
$ sudo yum list installed
List installed and available packages
$ sudo yum list all
List all packages (installed or available) that match a given [package-name], can be a glob
$ sudo yum list [package-name]
$ sudo yum list mysql*
Search for package
This searches for [package-name] across all repositories, also looking inside package descriptions.
$ sudo yum search [package-name]
Upgrade all system packages
$ sudo yum upgrade
This command installs all of the latest versions of each package installed on the system and is, generally, not recommended to be run on production systems.
Reinstall a single package
Sometimes, it’s necessary to force reinstallation of a package.
$ sudo yum reinstall [package-name]
View info for a package
$ sudo yum info [package-name]
Find which RPM package installs a given file
This command is very handy when it’s not obvious which package needs to be installed to use it.
$ sudo yum provides [file]
yum provides
can also take a glob:
$ sudo yum provides "*/bin/vim"
List all dependencies for a given package
$ sudo yum provides [package-name]
Package Groups
Note: yum now has a groups
subcommand for group operations, versions before 3.4.x should refer to this document instead.
yum has the concept of “package groups”, groups of related packages that can be installed or uninstalled at once, that don’t necessarily depend on each other.
List all groups
$ sudo yum group list
Install all packages for a group
$ sudo yum group install "Basic Web Server"
Remove all packages for a group
$ sudo yum group remove "Basic Web Server"
Repository Management
List all repositories
$ sudo yum repolist
List all packages for a given [repository]
(Note: yum > 3.4.x only)
$ sudo yum repo-pkgs [repository] list
Install all packages from given [repository]
(Note: yum > 3.4.x only)
$ sudo yum repo-pkgs [repository] install
Remove all packages from a given [repository]
(Note: yum > 3.4.x only)
$ sudo yum repo-pkgs [repository] remove
Update local metadata cache
This is run automatically by yum as needed, but can be refreshed manually with yum makecache
$ sudo yum makecache
When this command is run, all available packages are fetched and re-indexed from the repositories yum knows about.
yum-utils and yumdownloader
In order to download source packages, it’s necessary to install an additional package for yum, called “yum-utils”, which provides a yumdownloader
binary, among other things.
Downloading RPMs
Downloading RPM from remote repositories
$ sudo yumdownloader [package-name]
Downloading Source RPMs
$ sudo yumdownloader --source [package-name]
Downloading all dependencies for an RPM
$ sudo yumdownloader --resolve [package-name]
Filtering by architecture
$ sudo yumdownloader --archlist=[arch-list] [package-name]
More
yum-utils adds other useful commands to yum
that are too specific to cover here but are still worth looking over at the YumUtils website.
The Future: DNF
DNF is the next generation of package management for redhat based operating systems. Currently, it exists as a fork of yum 3.4 that use libsolv as its dependency solver. It is currently in use by the Fedora distribution.
Conclusion
Getting more familiar with your package manager’s tools can help you be more productive when finding, installing, and querying packages.
We highly recommend that users of production redhat based systems become familiar with yum
and dnf
.
You can learn more about the tools mentioned in this blog post by reading the man page: man 8 yum