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[[Category:OPS235]] {{Admon/caution|DraftLab|This lab has NOT been released for regular distribution. When the lab is ready to be released, this caution banner will disappear.}} =OPS235 Lab 5 - Archiving Files, Compiling Software Packages from Source, Managing Services=

* In this lab, you are going to help conserve disk space by learning how to compress and decompress files that are stored on your computer server. In addition, you will learn alternative methods of how to install programs (via git, and decompressing zipped tarball archives and then compiling source code).

==Required Materials (Bring to All Labs)==

* '''Fedora 16 17 LIVE CD''' - You can burn this onto a CD-R in the Open Lab* '''Fedora 16 x_64 17 x86_64 Installation DVD''' - You can burn this onto a DVD-R in the Open Lab (or burn image onto a DVD+R if you are using the Freedom Toaster).* '''SATA Hard Disk''' (in removable disk tray)* '''USB Memory Stick''' (minimum 64M)* '''Lab Logbook (Lab5 Reference Sheet)''' (to make notes and observations).

*[http://linuxmanpages.com/man8man1/tar.81.php tar]*[http://linuxmanpages.com/man8man1/gizgzip.81.php gzip]*[http://linuxmanpages.com/man8man1/gunzipizgunzip.81.php gunzipzip]*[http://linuxmanpages.com/man8man1/make.81.php make]*[http://schacon.github.com/git/git.html git]

#Boot up your '''fecora3fedora3''' VM.

#Boot up your '''fecora2fedora2''' VM.<!-- corrected a couple typos Eric D.--># Issue the following command to install a basic set of development tools and libraries:<br /><code>yum groupinstall "Development Tools" "Development Libraries"</code>.

==='''Answer the Investigation 4: Using git===3 observations / questions in your lab log book.'''

The runlevel command is now deprecated in Fedora, and has been replaced by '''systemctl'''. The newer system called '''systemd''' is a newer method to help simplify controlling both runlevels (referred to as "targets" and system services (referred to as "services"). Refer to the tutorial [[init vs systemd]] for systemctl command usages and reference.<ol> <li>Issue the following Linux command: <ul> <li><code>systemctl list-units --type===Investigation 5target</code></li> </ul> </li> <li>Note the target labelled graphical. Now trace the chain of links starting at /etc/systemd/system/default.target - what's it ultimately pointing to?</li> <li>Issue the following commands to switch the default mode (also known as target, formerly runlevel): <ul> <li><code>rm /etc/systemd/system/default.target</code></li> <li><code>ln -s /lib/systemd/system/multi-user.target /etc/systemd/system/default.target</code></li> </ul> <li>Restart your fedora2 VM. What happens?</li> <li>Log into your regular user account.</li> <li>Issue the following Linux command: <ul> <li><code>startx</code></li> </ul> </li> <li>What happens?</li> <li>Log-off your graphical system. You should return to your shell prompt.</li> <li>Issue the following commands: How do we Manage Runlevels and System Services <ul> <li><code>rm /etc/systemd/system/default.target</code></li> <li><code>ln -s /lib/systemd/system/graphical.target /etc/systemd/system/default.target</code></li> </ul> </li> <li>Reboot your fedora2 VM. What Happens?===</li></ol>

{{Admon/note|Use fedora2|Perform these steps in the '''fedora2Answer the Investigation 4 observations / questions in your lab log book.''' virtual machine.}}

{{Admon/important| Security Advice | We have seen that maintaining unneeded packages can be a security risk due to the unnecessary increase in the complexity of your system. Similarly, it is also unnecessarily hazardous, and even more so, to leave unneeded services running. In this investigation, === Investigation 5: How do we will learn how to control services, and turn off those that we think are not necessary.}}Manage System Services? ===

#Determine your current runlevel using the <code>runlevel<{{Admon/code> command.#Change to the appropriate startup directory note|Remain in a terminal window. For example, if your runlevel is 4, change to <code>/etc/rc.d/rc4.d</code>#Observe the names of the symbolic links fedora2 VM|Perform these steps in that directory. What is the target (destination) of the links to?# If you are not using the graphical user interface (GUI), use the ''startx'fedora2'' command to start it.#Run the menu option <code>System>Administration>Services</code>. You will then see the Service Configuration screen.#Find the <code>bluetooth</code> service and select customize from the tool bar. and deselect the checkbox for your runlevel from step 1. Quit the app.#Return to the terminal window you used in Step 2. Get a listing of the symbolic links in the startup directory. Is it any different from what you observed previously?#Using the Service Configuration screen, re-enable the <code>bluetooth</code> service. #Check the symbolic links again. What has changed this time?#Run this command:#*<code>chkconfig bluetooth off</code>#Now what has changed in the directory?#Run this command:#*<code>chkconfig bluetooth on</code>#Now what has changed?#Run the command:#*<code>chkconfig --list</code>#What does the output show?#What is the relationship between the Service Configuration tool, the symbolic links in the startup directory, and the <code>chkconfig</code> command?#You can also use <code>chkconfig</code> to set services to be on or off for certain runlevels. For example, to turn httpd on for runlevel 4, we issue the command:#*<code>chkconfig --level 4 httpd on</code>#To turn it off, we type:#*<code>chkconfig --level 4 httpd off</code>#To increase your computer's security, make sure these services are disabled:#*btseed, bttrack, cups, irda, mdmonitor, netfs, nfs, nfslock, pcscd, rpcgssd, rpcidmapd, rpcsvcgssd, sendmail, ypbind.{{Admon/note|Determining Required Services|You should understand that while most services in this list are often not needed, or are needed under circumstances different than those which occur here, there may be situations in which some of them are required, and it may be up to you as an administrator to determine which services are needed, and which should be turned offvirtual machine.}}

You We have seen that maintaining unneeded '''packages can find out some basic information about be a particular service by querying <code>rpm</code> for information about security risk''' due to the package that installed unnecessary increase in the service file in <code>/etc/rccomplexity of your system.d/init.d</code>Similarly, it is also unnecessarily hazardous, and even more so, to leave unneeded services running. For exampleIn this investigation, we will learn how to find out about the <code>cups</code> service'''control services, execute: <code>rpm -qif /etc/rc.d/initand turn off those services that we think are not necessary to help reduce security risks'''.d/cups</code>}}

#[ Compressed files: ] <code>/tmp/fstestarchive1.tar.gz</code> filesystem counted with files copied to itand <code>/tmp/archive2.tgz</code>#[ ] <code>nled</code> application is installed#[ ] Correct services are disabledLab5 notes how to use systemctl commands#[ ] <code>/lab5</code> has an entry in <code>/etc/fstab</code>VMs backed-up

==Preparing for the Quizzes==

#How do you ensure that a filesystem What is mounted every time the system is started?#How is creating and using a filesystem in a file different from creating and using a filesystem in a block device (such as purpose of a partition)repository?

#How do you use <code>chkconfigsystemctl</code>?to:#The startup directory for each *list runlevel contains symbolic links. Where are the targets of the symbolic links#*list services#*stop a service#*start a service#*Why is it important to learn how to manage services?#When you use the menu option System>Administration>Services, what program *Why is runit important to stop certain services?