DNF Package Manager: Complete Guide for Fedora/RHEL 8+

Table of Contents

1. [Introduction](#introduction) 2. [Basic Concepts](#basic-concepts) 3. [Installation and Configuration](#installation-and-configuration) 4. [Core Commands](#core-commands) 5. [Package Management Operations](#package-management-operations) 6. [Repository Management](#repository-management) 7. [Advanced Features](#advanced-features) 8. [Configuration Files](#configuration-files) 9. [Troubleshooting](#troubleshooting) 10. [Best Practices](#best-practices)

Introduction

DNF (Dandified YUM) is the next-generation package manager for RPM-based Linux distributions, serving as the default package manager for Fedora 22+ and Red Hat Enterprise Linux 8+. It replaced YUM (Yellowdog Updater Modified) with improved performance, better dependency resolution, and enhanced features.

DNF handles the installation, removal, and management of software packages in RPM format. It automatically resolves dependencies, manages repositories, and provides a robust command-line interface for system administration tasks.

Key Features

- Improved Performance: Faster metadata processing and package operations - Better Dependency Resolution: Advanced SAT solver for complex dependency scenarios - Memory Efficiency: Lower memory footprint compared to YUM - Plugin Architecture: Extensible through plugins - Transaction History: Complete tracking of package operations - Modular Content Support: Support for application streams and modules

Basic Concepts

Package Management Terminology

| Term | Description | |------|-------------| | Package | A compiled software bundle containing executables, configuration files, and metadata | | Repository | A collection of packages stored on a server or local storage | | Metadata | Information about packages including dependencies, descriptions, and versions | | Transaction | A set of package operations performed atomically | | Group | A collection of related packages that can be installed together | | Module | A set of RPM packages representing an application, language runtime, or database |

Package States

| State | Description | |-------|-------------| | Available | Package exists in configured repositories but not installed | | Installed | Package is currently installed on the system | | Upgradeable | Newer version available in repositories | | Obsoleted | Package replaced by another package | | Broken | Package has unresolved dependencies |

Installation and Configuration

Installing DNF

DNF comes pre-installed on Fedora 22+ and RHEL 8+. For older systems or minimal installations:

`bash

On RHEL/CentOS 8

On Fedora (if somehow missing)

Initial Setup

After installation, update the package database:

`bash sudo dnf makecache `

This command downloads and caches repository metadata for faster subsequent operations.

Core Commands

Basic Syntax

`bash dnf [options] [arguments] `

Essential Commands Reference

| Command | Purpose | Example | |---------|---------|---------| | install | Install packages | dnf install firefox | | remove | Remove packages | dnf remove firefox | | update | Update packages | dnf update | | search | Search for packages | dnf search editor | | info | Display package information | dnf info vim | | list | List packages | dnf list installed | | check-update | Check for updates | dnf check-update | | clean | Clean cache | dnf clean all |

Command Options

| Option | Description | Example | |--------|-------------|---------| | -y, --assumeyes | Automatically answer yes to prompts | dnf -y install package | | -q, --quiet | Quiet operation | dnf -q list | | -v, --verbose | Verbose output | dnf -v install package | | --nogpgcheck | Skip GPG signature verification | dnf --nogpgcheck install package | | --downloadonly | Download packages without installing | dnf --downloadonly install package | | --enablerepo | Enable specific repository | dnf --enablerepo=repo install package | | --disablerepo | Disable specific repository | dnf --disablerepo=repo install package |

Package Management Operations

Installing Packages

#### Single Package Installation `bash

Install a single package

Install with automatic confirmation

Install specific version

#### Multiple Package Installation `bash

Install multiple packages

Install from local RPM file

Install from URL

#### Conditional Installation `bash

Install only if not already installed

Install with best candidate selection

Removing Packages

#### Basic Removal `bash

Remove single package

Remove multiple packages

Remove with dependencies (autoremove)

#### Advanced Removal Options `bash

Remove packages and unused dependencies

Remove all packages matching pattern

Simulate removal (dry run)

Updating Packages

#### System Updates `bash

Update all packages

Update with automatic confirmation

Check for available updates

#### Selective Updates `bash

Update specific package

Update packages from specific repository

Update security patches only

#### Update Exclusions `bash

Exclude specific packages from update

Update everything except specific packages

Searching and Querying Packages

#### Search Operations `bash

Search by package name

Search in package descriptions

Search for files provided by packages

#### Package Information `bash

Display detailed package information

Show package dependencies

Show what packages depend on this package

List files in package

#### Listing Packages `bash

List all installed packages

List available packages

List upgradeable packages

List packages by pattern

Package Groups

#### Group Operations `bash

List available groups

Install package group

Remove package group

Show group information

#### Group Management Examples

| Group Name | Description | Install Command | |------------|-------------|-----------------| | "Development Tools" | Compilers and development utilities | dnf group install "Development Tools" | | "System Tools" | System administration tools | dnf group install "System Tools" | | "Security Tools" | Security and monitoring tools | dnf group install "Security Tools" | | "Multimedia" | Audio and video applications | dnf group install "Multimedia" |

Repository Management

Repository Configuration

#### Listing Repositories `bash

List enabled repositories

List all repositories (enabled and disabled)

Show repository information

#### Repository Operations `bash

Enable repository temporarily

Disable repository temporarily

Enable repository permanently

Disable repository permanently

#### Adding New Repositories `bash

Add repository from URL

Add RPM Fusion repositories (Fedora)

Add EPEL repository (RHEL/CentOS)

Repository Configuration Files

Repository configurations are stored in /etc/yum.repos.d/. Example repository file:

`ini [example-repo] name=Example Repository baseurl=https://example.com/repo/ enabled=1 gpgcheck=1 gpgkey=https://example.com/repo/RPM-GPG-KEY `

#### Repository Configuration Parameters

| Parameter | Description | Values | |-----------|-------------|--------| | name | Human-readable repository name | String | | baseurl | Repository URL | URL | | enabled | Enable/disable repository | 0 or 1 | | gpgcheck | Verify GPG signatures | 0 or 1 | | gpgkey | GPG key location | URL or file path | | priority | Repository priority | Number (1-99) | | includepkgs | Include only specified packages | Package patterns | | excludepkgs | Exclude specified packages | Package patterns |

Advanced Features

DNF Modules

Modules provide multiple versions of applications and runtime environments.

#### Module Operations `bash

List available modules

Show module information

Install module stream

Enable module stream

Disable module

Reset module

#### Module Management Examples

| Module | Available Streams | Default | Command | |--------|------------------|---------|---------| | nodejs | 10, 12, 14, 16 | 14 | dnf module install nodejs:16 | | python | 2.7, 3.6, 3.8, 3.9 | 3.8 | dnf module install python:3.9 | | postgresql | 9.6, 10, 11, 12, 13 | 12 | dnf module install postgresql:13 | | nginx | 1.16, 1.18, 1.20 | 1.18 | dnf module install nginx:1.20 |

Transaction History

#### History Commands `bash

Show transaction history

Show detailed transaction information

Undo transaction

Redo transaction

Rollback to specific transaction

#### History Information Table

| Column | Description | |--------|-------------| | ID | Transaction identifier | | Command Line | Original command executed | | Date and time | When transaction occurred | | Action(s) | Install, Update, Remove, etc. | | Altered | Number of packages affected |

DNF Plugins

#### Common Plugins

| Plugin | Purpose | Installation | |--------|---------|--------------| | dnf-automatic | Automatic updates | dnf install dnf-automatic | | dnf-plugins-core | Core plugin collection | Usually pre-installed | | dnf-utils | Additional utilities | dnf install dnf-utils | | needs-restarting | Check restart requirements | Part of dnf-utils |

#### Plugin Usage Examples `bash

Check which services need restart after updates

Download packages to specific directory

Show package changelog

Find which package owns a file

Performance Optimization

#### Cache Management `bash

Clean all cache

Clean only metadata

Clean packages cache

Make cache for faster operations

#### Parallel Downloads Configure parallel downloads in /etc/dnf/dnf.conf:

`ini [main] max_parallel_downloads=10 fastestmirror=true deltarpm=true `

Configuration Files

Main Configuration File

The primary DNF configuration file is /etc/dnf/dnf.conf:

`ini [main] gpgcheck=1 installonly_limit=3 clean_requirements_on_remove=True best=False skip_if_unavailable=True max_parallel_downloads=5 fastestmirror=True deltarpm=True `

#### Configuration Options

| Option | Description | Default | Recommended | |--------|-------------|---------|-------------| | gpgcheck | Verify package signatures | 1 | 1 | | installonly_limit | Keep N versions of kernel | 3 | 3 | | clean_requirements_on_remove | Remove unused dependencies | True | True | | best | Always try to install best candidate | False | True | | skip_if_unavailable | Skip unavailable repositories | True | True | | max_parallel_downloads | Concurrent downloads | 3 | 5-10 | | fastestmirror | Use fastest mirror | False | True | | deltarpm | Use delta RPMs for updates | True | True |

User Configuration

Users can create personal configuration at ~/.config/dnf/dnf.conf or use aliases:

`bash

Add to ~/.bashrc

Troubleshooting

Common Issues and Solutions

#### Dependency Problems `bash

Check for broken dependencies

Fix broken dependencies

Force reinstall problematic package

Skip broken packages

#### Repository Issues `bash

Refresh repository metadata

Check repository status

Test repository connectivity

#### Lock File Issues `bash

Remove lock file (if DNF crashed)

Check for running DNF processes

Kill stuck DNF processes

Error Messages and Solutions

| Error | Cause | Solution | |-------|-------|----------| | "No package X available" | Package not in repositories | Check repository configuration | | "Nothing to do" | Package already installed/updated | Use dnf list to verify status | | "Insufficient space" | Not enough disk space | Clean cache or free disk space | | "GPG signature verification failed" | Invalid package signature | Check GPG keys or use --nogpgcheck | | "Cannot retrieve metalink" | Network/repository issue | Check internet connection and repository URLs |

Debugging Commands

Verbose output for debugging

Show detailed transaction information

Check system integrity

Verify installed packages

Best Practices

Security Best Practices

1. Always verify GPG signatures `bash # Ensure gpgcheck=1 in configuration grep gpgcheck /etc/dnf/dnf.conf `

2. Keep system updated regularly `bash # Set up automatic security updates sudo dnf install dnf-automatic sudo systemctl enable --now dnf-automatic-install.timer `

3. Use trusted repositories only `bash # Review enabled repositories dnf repolist `

Performance Best Practices

1. Enable parallel downloads `ini # In /etc/dnf/dnf.conf max_parallel_downloads=10 `

2. Use fastest mirror `ini # In /etc/dnf/dnf.conf fastestmirror=true `

3. Regular cache maintenance `bash # Weekly cache cleanup sudo dnf clean all && sudo dnf makecache `

System Maintenance

#### Regular Maintenance Tasks

| Task | Frequency | Command | |------|-----------|---------| | System updates | Weekly | sudo dnf update | | Cache cleanup | Weekly | sudo dnf clean all | | Remove orphaned packages | Monthly | sudo dnf autoremove | | Check for broken dependencies | Monthly | dnf check | | Review installed packages | Quarterly | dnf list installed |

#### Automation Scripts

Create maintenance script /usr/local/bin/dnf-maintenance.sh:

`bash #!/bin/bash

DNF Maintenance Script

echo "Starting DNF maintenance..."

Update system

Remove orphaned packages

Clean cache

Check for issues

echo "DNF maintenance completed." `

Monitoring and Logging

#### Log Files

| Log File | Purpose | |----------|---------| | /var/log/dnf.log | DNF operations log | | /var/log/dnf.rpm.log | RPM transaction log | | /var/log/dnf.librepo.log | Repository access log |

#### Monitoring Commands `bash

Monitor real-time DNF operations

Check recent package installations

Review system changes

This comprehensive guide covers all aspects of DNF package management, from basic operations to advanced features and troubleshooting. Regular practice with these commands and adherence to best practices will ensure efficient and secure package management on Fedora and RHEL 8+ systems.