tmdahiya1409-c352236b

2 weeks ago

Linux Commands

I am bit confused with Linux Commands, we install packages in system like below,


yum install <package>
yum install -y <package>
dnf install <package>
apt-get install <package>


On searching google, apt is used for debian and yum is used for Cent family OS. But why we need dnf ?? Sometimes authors are install epel-release, why?? what it's use?

As a beginner its blows my mind, please differentiate these things so that I can visualise.

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tmdahiya1409-c352236b
2 weeks ago
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tmdahiya1409-c352236b
2 weeks ago
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kevinpjames
2 weeks ago
Hi. dnf is new and will the way forward for Red Hat 8 and Centos 8.  In the RHEL8 and Centos 8 the yum command is now a link to the dnf command.  So when you use yum it's actually running dnf. 

The use of the epel-release packages is to add some extra software that isnt available as standard.  So if you tried to install a package thats only in the epel-release 'set' of packages and dont have the epel-release installed, then you will get a message saying the package isnt found.    So basically the epel is to 'extend' the available software you can install. 
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kevinpjames
2 weeks ago

Red Hat say "The YUM package manager is now based on the DNF technology and it provides support for modular content, increased performance, and a well-designed stable API for integration with tooling."


The release notes for Red Hat 8 package manager can be found here and they talk about dnf there.

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/RHEL-8_0_0_release#software-management


The full release notes for Red Hat 8 can be found here.  And you have the ability to download them as a pdf or as other formats.https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/index


I hope this helps and answers your questions.


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tmdahiya1409-c352236b
2 weeks ago
As you said "epel-release packages is to add some extra software that isnt available as standard", basically every system comes with the default set of softwares and user install new softwares according to  their use & for this purpose user can also use yum/dnf. So why we need epel-release, which packages does it install that yum/dnf cant do?
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kevinpjames
1 week ago

Fyi.  Here is a link to the webpage for epel-release that has more info.  https://fedoraproject.org/wiki/EPEL.
On the site they say the following,

"The EPEL project strives to provide packages with both high quality and stability. However, EPEL is maintained by a community of people who generally volunteer their time and no commercial support is provided. "

One of the packages I like to use on a linux desktop or graphical interface is software called gkrellm.  It's not available in the standard or extras repo's but is available in epel. 

Also some of the packages in the epel-release are also in the standard but are newer versions, or different versions.  An example is Ansible.  Without the epel-release enabled, if I try and install ansible I get version 2.4.2.0-2.el7.  When the epel is enabled I get version 2.8.4-1.el7, so sometimes it's to get packages that are newer but not yet incorporated in the standard.