Package Management (apt/dnf) Cheat Sheet

Install, update, remove and search for packages on Debian/Ubuntu (apt) and RHEL/Fedora (dnf), side by side.

A side-by-side reference for the two package managers you’ll meet most often: apt on Debian/Ubuntu, and dnf on Fedora/RHEL/Rocky/Alma. Same job, different commands — this sheet lines them up so you stop guessing which one a given server needs.

Update the package index

sudo apt update      # refresh the list of available packages and versions

sudo dnf check-update # same idea - dnf refreshes its cache automatically on most commands

apt update only refreshes metadata — it does not install anything yet. dnf refreshes its cache as needed on its own, so check-update is mostly for seeing what’s pending.

Upgrade installed packages

sudo apt upgrade          # upgrade all packages to their newest available version
sudo apt full-upgrade     # like upgrade, but also allowed to remove packages if a dependency requires it

sudo dnf upgrade          # upgrade all packages (dnf's equivalent of full-upgrade)

Run apt update (or let dnf refresh) before upgrading, and read what’s about to change — full-upgrade/dnf upgrade can remove packages, which matters on a production server.

Install a package

sudo apt install nginx        # install nginx, plus anything it depends on
sudo apt install nginx=1.24.0-1  # install a specific version, if available in the repo

sudo dnf install nginx        # same idea on Fedora/RHEL
sudo dnf install nginx-1.24.0 # specific version syntax varies by package

Remove a package

sudo apt remove nginx     # remove the package, keep its config files in /etc
sudo apt purge nginx      # remove the package AND its config files

sudo dnf remove nginx     # removes the package (dnf doesn't separate remove/purge the same way)

purge deletes configuration too — only reach for it when you actually want a clean slate, not just to free disk space.

Search for a package

apt search nginx          # search package names and descriptions
apt show nginx            # full details: version, dependencies, description

dnf search nginx          # same idea
dnf info nginx            # full details, dnf's equivalent of apt show

List installed packages

apt list --installed              # every installed package
apt list --installed | grep nginx # narrow it down to one
dpkg -l | grep nginx              # lower-level alternative, works even if apt itself is broken

dnf list installed                # every installed package
dnf list installed | grep nginx   # narrow it down
rpm -qa | grep nginx              # low-level alternative, dnf's equivalent of dpkg -l

Find which package owns a file

dpkg -S /usr/sbin/nginx    # "which package put this file here?"

rpm -qf /usr/sbin/nginx    # same question, RPM-based systems

Useful when you find a binary or config file and don’t know what installed it — common during troubleshooting or auditing an unfamiliar server.

Clean up disk space

sudo apt autoremove   # remove packages that were auto-installed as dependencies and are no longer needed
sudo apt autoclean    # delete cached .deb files for packages no longer installed
sudo apt clean        # delete ALL cached .deb files, even for currently installed packages

sudo dnf autoremove   # same idea - drop orphaned dependencies
sudo dnf clean all    # clear dnf's cached metadata and packages

Adding a repository

sudo add-apt-repository ppa:ondrej/php   # add a third-party PPA (Ubuntu)
sudo apt update                          # refresh the index so the new repo's packages show up

sudo dnf install epel-release   # enable the EPEL repo (common extra repo on RHEL/Rocky/Alma)
sudo dnf config-manager --add-repo <url>  # add an arbitrary .repo URL

Only add repositories you trust — a repo can serve arbitrary, unsigned-by-default software with root install privileges. Prefer well-known, actively maintained sources.

Holding a package at its current version

sudo apt-mark hold nginx     # prevent nginx from being upgraded by future `apt upgrade` runs
sudo apt-mark unhold nginx   # allow it to be upgraded again

sudo dnf versionlock add nginx     # equivalent on dnf (needs the versionlock plugin installed)
sudo dnf versionlock delete nginx  # remove the lock

Useful when a newer version breaks something you depend on and you need to stay on a known-good release temporarily — remember to actually go back and upgrade later once it’s fixed.

Quick reference table

Task	apt (Debian/Ubuntu)	dnf (Fedora/RHEL family)
Refresh index	`apt update`	`dnf check-update`
Upgrade all	`apt full-upgrade`	`dnf upgrade`
Install	`apt install <pkg>`	`dnf install <pkg>`
Remove	`apt purge <pkg>`	`dnf remove <pkg>`
Search	`apt search <term>`	`dnf search <term>`
Package info	`apt show <pkg>`	`dnf info <pkg>`
List installed	`dpkg -l`	`rpm -qa`
Who owns this file	`dpkg -S <path>`	`rpm -qf <path>`
Clean cache	`apt clean`	`dnf clean all`

Safety notes

Always run an update/refresh before installing or upgrading, so you’re working from current package information.
Read what a command is about to remove before confirming, especially full-upgrade/dnf upgrade and anything involving purge.
Only add third-party repositories you trust — they run with the same root privileges as your official ones.
On a production server, test package upgrades on a staging box first where possible; a routine upgrade can still change a config file’s default or a service’s behavior.