yum

Overview

yum (Yellowdog Updater Modified) is the classic RPM package manager front-end for older RHEL/CentOS/Scientific Linux systems. On RHEL 8+/Fedora/CentOS Stream, the command is typically a compatibility wrapper around dnf. Prefer dnf on modern systems; learn yum for legacy fleets and muscle-memory commands that still work.

Syntax

yum [options] command

Common Commands

Command	Description
install	Install packages
remove / erase	Remove packages
update / upgrade	Update packages
info	Package details
list	List packages
search	Search metadata
provides / whatprovides	Which package owns a capability/file
repolist	Enabled repos
clean all	Clean caches
history	Transaction history
groupinstall	Group install
check-update	Check without installing

Common Options

Option	Description
-y	Assume yes
-q	Quiet
--enablerepo= / --disablerepo=	Toggle repos for one shot
--setopt=	Override config
--downloadonly	Download, don’t install
--security	Security updates (plugin/platform dependent)
-C	Run from cache only

Examples with Explanations

Everyday

sudo yum check-update
sudo yum update -y
sudo yum install -y curl vim
sudo yum remove -y oldpkg

Search and info

yum search nginx
yum info nginx
yum list installed 'nginx*'
yum provides /usr/bin/ps

Repos

yum repolist
yum repolist all
sudo yum-config-manager --enable powertools   # platform specific

History / undo

sudo yum history
sudo yum history info 42
sudo yum history undo 42

Clean cache

sudo yum clean all
sudo yum makecache

Prefer dnf when present

command -v dnf && dnf --version
sudo dnf install -y htop      # modern path
# yum may redirect:
yum --version

Groups

yum group list
sudo yum groupinstall -y "Development Tools"

Notes / Pitfalls

• RHEL 8+: yum → dnf API; some old yum plugins differ.
• -y in unattended scripts needs good testing (major upgrades).
• Multiple transactions: watch disk space for /var/cache.
• Proxy and mirror issues show as metadata download failures.
• EPEL and third-party repos change availability — pin carefully.

2026-relevant notes

• New work: document dnf first; mention yum as alias/legacy.
• CentOS Linux classic is EOL — care with unmaintained mirrors.
• For containers, use minimal base images and explicit package lists rather than interactive yum sessions.

Related Commands

• dnf — modern replacement
• rpm — low-level RPM queries/installs
• repoquery — rich queries (dnf/yum tools)
• subscription-manager — RHEL entitlements
• apt — Debian family analog

Additional Resources

• man yum, man dnf
• RHEL system admin docs for your major version