|}
#Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum install elinks</span></code></b>yum info elinks</span></code></b>
#How can you tell if the elinks package has been installed?
#To remove the elinks package issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum remove elinks</span></code></b>
<ol>
<li value="29">Issue Within the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum install elinks</span></code></b> and answer <b><code><span style="color:#3366CC;font-size:1.2em;">y</span></code></b> to Packages subdirectory of the question about installation. <ol type="a"> <li>Where did ''yum'' get Centos Full Install DVD, locate the elinks software?</li> <li>Why could ''yum'' install elinks when rpm couldn't?</li> </ol> </li> <li>Issue an RPM query to verify file that elinks contains the xchat application. What do you think is installed. Record this command the purpose of the numbers also contained in your lab log-book.the filename?</li> <li>Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum remove elinkslocalinstall absolute_pathname_to_xchat_rpm_file</span></code></b></li> <li>Issue an RPM query to verify Verify that elinks is no longer the '''xchat''' command has been installed. Record this command in your lab log-book.</li> <li>Issue this command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum info cups</span></code></b></li>
</ol>
::* Based on the result, do you think that cups is a useful package for your system? If not, try removing it.
<ol>
<li value="8">Unused and unneeded software can present a security risk and ties up disk space needlessly. Find at least 4 other packages (for example: games, sound & video, etc) that you're not using on your system, and remove them. Be careful to ensure that removing those packages does not also remove other software that you do need.</li>
</ol>
{| width="40%" align="right" cellpadding="10"
|colspan="2"|{{Admon/note|A Note about Repositories|Since software repositories are on-line storage areas for software for particular Linux distributions, the Linux administrator can enable (add) or disable (remove) additional software repositories. Usually only the basic or "base" repositories are enabled upon Linux installation.}}
|}
# <ol><li value="12">Use the yum command to install the package called "x". Were you able to install the file?# </li><li>As root, issue the following command: <b><code><span style="color:#3366CC;font-size:1.3em;">more /etc/yum.conf</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>Before adding a repository to the yum.conf file, you need to see which repositories you want to add, and obtain the appropriate URL for those repositories. View the following link to see a general listing of repositories: [ [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: '''SerNet Samba Repository'''. You will use in the next command you issue# (see below).</li><li>To add the repository, issue the command: <b><code><span style="color:#3366CC;font-size:1.3em;">yum-config-manager --add-repo URL_of_SerNET_Samba_Repository</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-config-manager --enable repository_name</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>Now use the yum command to install the package called "x". Were you successful, and if so, why?</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. Find at least 4 other packages (for example: '''sound & video''', '''games''', etc) that you're not using on your system, and remove them. Be careful to ensure that removing those packages does not also remove other software that you do need.</li></ol>
'''Answer Investigation 3 observations / questions in your lab log book.'''