<li value="13">We will now look at how we can add different repositories to our '''c7host''' machine.</li><li>As root, issue the following command: <b><code><span style="color:#3366CC;font-size:1.3em;">yum repolist</span></code></b></li><li>Take a few moments to view the contents of the file. Do you see which repositories are used by the '''yum''' command? Write down the repositories in your lab logbook.</li><li>View the following link to see a general listing of repositories:<br>[ [http://wiki.centos.org/AdditionalResources/Repositories Available Repositories for Centos] ].</li><li>After viewing the repository list, why should you be cautious with adding just any repository into your yum.conf file?</li><li>Obtain the URL for the repository: '''extra EPEL repositories'''. You will use in the next command (see below).</li><li>To add the this repository, issue the command: <b><code><span style="color:#3366CC;font-size:1.3em;">wget https://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-5.noarch.rpm</span></code></b></li><li>To enable the repository in yum, issue the following command: <b><code><span style="color:#3366CC;font-size:1.3em;">yum install epel-release-7-5.noarch.rpm</span></code></b></li><li>To clean-up the repository list (including downloading new applications in added repositories), issue the command: <b><code><span style="color:#3366CC;font-size:1.3em;">yum clean all</span></code></b></li><li>To verify that you have added the repository, you can issue the command: <b><code><span style="color:#3366CC;font-size:1.3em;">yum repolist</span></code></b></li><li>Perform a NetSearch to compare compiling source code vs using the yum command. What are the three major features that the '''yum''' command has that '''compiling source code''' doesn't?</li><li>Unused and unneeded software can present a security risk and ties up disk space needlessly.</li><li>Find '''at least 4 other packages''' to remove on your c7host machine(for example: '''sound & video''', '''games''', etc) that you're not using on your system. Be careful to ensure that removing those packages does not also remove other software that you do need.</li>