What Is YUM

This section provides a quick introduction on YUM (Yellowdog Update Modified), which is a software package manager for RPM (RedHat Package Manager) based Linux distributions.

What Is YUM? - YUM (Yellowdog Update Modified) is a software package manager for RPM (RedHat Package Manager) based Linux distributions.

YUM is replaced by DNF (Dandified YUM) on CentOS 8 systems now. If run a "yum ..." command, it will be executed as "dnf ...".

On my CentOS 8 computer, both "dnf" and "yum" commands invoke the same program called "dnf-3":

herong$ which yum
/usr/bin/yum

herong$ ls -l /usr/bin/yum
lrwxrwxrwx. 1 root root 5 Sep  17 2021 /usr/bin/yum -> dnf-3

herong$ which dnf
/usr/bin/dnf

herong$ ls -l /usr/bin/dnf
lrwxrwxrwx. 1 root root 5 Sep  17 2021 /usr/bin/dnf -> dnf-3

herong$ ls -l /usr/bin/dnf-3
-rwxr-xr-x. 1 root root 1954 Sep  17 2021 /usr/bin/dnf-3

So you should stop using YUM and get used to DNF. YUM will probably be removed in the next CentOS release.

Table of Contents

 About This Book

 Introduction to Linux Systems

 Cockpit - Web Portal for Administrator

 Process Management

 Files and Directories

 Users and Groups

 File Systems

 Block Devices and Partitions

 LVM (Logical Volume Manager)

 Installing CentOS

 SELinux - Security-Enhanced Linux

 Network Connection on CentOS

Software Package Manager on CentOS - DNF and YUM

 What Is DNF

 Manage DNF Package Repositories

What Is YUM

 What Is RPM

 What Is pkgs.org

 Install and Manage Java Packages on CentOS

 Install and Manage Perl Packages on CentOS

 Install "git-core" for GitHub Packages on CentOS

 Failed to Download Metadata for Repo ...

 Replacing CentOS Repositories to Local Mirrors

 vsftpd - Very Secure FTP Daemon

 Postfix - Mail Transport Agent (MTA)

 Dovecot - IMAP and POP3 Server

 Email Client Tools - Mail User Agents (MUA)

 LDAP (Lightweight Directory Access Protocol)

 Administrative Tasks

 References

 Full Version in PDF/EPUB