YUM (Yellowdog Updater Modified) is a powerful package management tool in CentOS and other RPM-based Linux distributions. It’s a reliable resource for installing, updating, and removing packages, along with their dependencies. Beyond the basics, YUM also supports package groups, allows package caching, and has a host of other features. This guide will help you navigate the advanced side of YUM and streamline your package management tasks.
YUM Installation and Update
Let’s start with a brief review of installing and updating packages. To install a package:
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yum install packageName
To update a package:
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yum update packageName
To update all packages:
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yum update
While these commands are basic, they are the cornerstone of any package management tasks you’ll be performing.
Group Management
YUM supports package groups, which are groups of packages that serve a similar purpose. For example, “Development Tools” is a package group.
To list all available groups:
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yum group list
To install a group:
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yum group install 'groupName'
This feature is incredibly useful for installing a suite of packages that serve a common purpose.
Search Packages
YUM allows you to search for packages using keywords related to the package. This can be particularly useful when you’re unsure of a package’s exact name:
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yum search keyword
The search results will display a list of packages that contain the keyword in their name or summary.
List Packages
YUM provides commands to list all available, installed, or specific packages:
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yum list all
yum list installed
yum list packageName
It is a great way to quickly view what’s available or installed on your system.
Package Info
The info command provides detailed information about a package:
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yum info packageName
This can be particularly useful when evaluating a package for potential installation.
Remove Packages
Removing a package is as simple as:
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yum remove packageName
YUM will take care of resolving and removing dependencies as well.
Clean YUM Cache
YUM stores package data from the repositories to which your system is connected. Over time, this cache may become cluttered with outdated package data. To clean all cached files from any enabled repository, use:
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yum clean all
This command is helpful for reclaiming disk space and ensuring up-to-date package data.
YUM History
One of the powerful features of YUM is its ability to maintain a detailed history of transactions. To view this history:
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yum history
You can use the history command to undo or redo certain transactions:
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yum history undo transactionID
yum history redo transactionID
This is an incredibly powerful feature that allows for detailed troubleshooting and system recovery.
Managing Repositories
YUM allows for the management of repositories from which it retrieves package data. To list all repositories:
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yum repolist
You can enable or disable repositories during package installations:
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yum --enablerepo=repositoryName install packageName
yum --disablerepo=repositoryName install packageName
This allows for granular control over the source of your packages.
Conclusion
Mastering YUM is an important part of managing CentOS and other RPM-based systems. While the basic commands are powerful and useful, delving into the more advanced features of YUM can vastly increase your efficiency and effectiveness as a system administrator.
Remember, practice makes perfect. Use these commands, play around with them, and see what works best for your workflow. In time, you’ll be navigating YUM like a pro. Happy package managing!
