When working with YUM package management on CentOS/RHEL systems, you might need to determine which repository a particular package was installed from. This becomes particularly important when:

• Debugging dependency conflicts between repositories
• Verifying package sources for security audits
• Maintaining consistent environments across servers

While yum info package-name shows basic information, it doesn't display the source repository for installed packages. Here's a more effective approach:

# Check available repositories
yum repolist

# Detailed package information including repository
yum info package-name --showduplicates

The most reliable method is to query YUM's database directly:

# For a specific package
yumdb get from_repo package-name

# Example output for httpd:
# from_repo=base

For multiple packages, you can combine commands:

rpm -qa | xargs -n 1 yumdb get from_repo

If you need to check installation history:

# View complete yum history
yum history

# Get details for a specific transaction
yum history info transaction-id

For graphical interfaces, you can use:

yumex

Let's say you're getting dependency errors with PHP packages. Here's how to investigate:

# First identify which PHP versions are installed
rpm -qa | grep php

# Then check each package's source
yumdb get from_repo php-common
yumdb get from_repo php-cli

# Compare with available versions
yum --showduplicates list php-common

For scripted solutions, you can parse YUM's cache directly:

# View raw cache data (XML format)
cat /var/cache/yum/x86_64/7/base/primary.xml.gz | gunzip | grep -A 10 "package-name"

When working with YUM package manager on RHEL/CentOS systems, you might need to identify which repository a particular package was installed from. This becomes crucial when:

• Debugging dependency issues
• Maintaining system consistency
• Auditing package sources
• Resolving repository conflicts

While yum info and yum list show installed packages, they don't reveal the source repository. Here's what you typically see:

$ yum info httpd
Installed Packages
Name        : httpd
Arch        : x86_64
Version     : 2.4.6
Release     : 97.el7.centos
Size        : 3.7 M
Repo        : installed

The yumdb command provides access to YUM's package database, including repository information:

$ yumdb get from_repo httpd
httpd-2.4.6-97.el7.centos.x86_64 from_repo=base

For packages installed in previous transactions, use:

$ yum history info httpd
Transaction ID : 42
Command Line  : install httpd
Packages Altered:
    Install httpd-2.4.6-97.el7.centos.x86_64 @base

Here's a bash script to check repository sources for all installed packages:

#!/bin/bash
for pkg in $(yum list installed | awk 'NR>1 {print $1}' | cut -d. -f1)
do
    repo=$(yumdb get from_repo $pkg 2>/dev/null)
    echo "$pkg : $repo"
done

For systems where yumdb isn't available, you can parse the cache:

$ grep -r "httpd-2.4.6" /var/cache/yum/
/var/cache/yum/x86_64/7/base/packages/httpd-2.4.6-97.el7.centos.x86_64.rpm

• Local installations won't show repository info
• Manually installed RPMs won't have from_repo data
• Repository metadata might be outdated

Knowing package origins helps maintain system integrity. For production systems, consider:

• Regularly cleaning yum cache (yum clean all)
• Documenting repository configurations
• Using version control for repo files