Changes

=[[Category:OPS235 Lab 5 - Loopback Filesystems, Archives, Compiling from Source=]]

{{Admon/caution | Caution! Draft Lab| This lab has NOT been released for regular distribution. When the lab is under constructionready to be released, this caution banner will disappear.}} =Archiving Files, Compiling Software Packages from Source, Managing Services=[[Category:OPS235]][[Category:OPS235 Labs]]  ==Overview== * 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 (decompressing zipped tarball archives and then compiling source code). * In addition, you will learn about how certain processes (services) work, and how the system administrator can manage these services (i.e. turn "on" and "off").

#Compiling software packages from source code#Customizing Install an application from software development repositories using the bit utility#Customising file-system startupstart-up 

==PrerequisitesLinux Command Online Reference==Each Link below displays online manpages for each command (via [http://linuxmanpages.com/ http://linuxmanpages.com]):

{|width="100%" cellpadding="5"|'''Archiving Utilities:'''|'''Service Management Utilities:'''||- valign="top"|*[http://linuxmanpages.com/man1/tar.1.php tar]*[http://linuxmanpages.com/man1/gzip.1.php gzip]*[http://linuxmanpages.com/man1/gunzip.1.php gunzipzip]* Completion of Labs [http://linuxmanpages.com/man1/make.1-4.php make]|*[http://www.linuxcertif.com/man/1/systemctl/ systemctl]

==Investigation 1: How do you create and use a filesystem in a regular file?Resources on the web==Additional links to tutorials and HOWTOs:* [http://www.centos.org/docs/2/rhl-gsg-en-7.2/s1-zip-tar.html archiving with tar, gzip, gunzip]* [http://www.tuxfiles.org/linuxhelp/softinstall.html Compiling Software from Source Code]* [[init vs systemd]]

{{Admon==Archiving Files /note|Use fedora3|Perform these steps in the '''fedora3''' virtual machine.}}Compiling Software from Source Code==

#Login using your Learn ID#Create an empty file that is exactly 3 MB in size:#*<code>dd if=/dev/zero of=/tmp/fstest bs=1k count=3072</code>#How does this command ensure that the file is 3 MB in size? What is in the file at first?#Create an ext3 filesystem within the newly-created file <code>/tmp/fstest</Archive files are often used to contain source code>. Note the warning message/question that appears#Mount the filesystem (remember to use the loopback optionfor software; refer to Lab 1 if required). Use a mountpoint of your choosing.#Copy the files <code>/etc/services</code> and <code>/etc/protocols</code> to the filesystem mounted in the previous step#Unmount the filesystem#Test your filesystem to this lab you will also be sure that the files <code>/etc/services</code> and <code>/etc/protocols</code> were in fact copied into the filesystem within the file named <code>/tmp/fstest</code>. #How much space is left in that filesystem? (Hint: <code>df -h</compiling software from a source code>)archive.

Make sure that your {{Admon/note|Do not Shut-Down VMs Until Instructed|You will be running all 3 VMs eventually when performing this tutorial, Leave all VMs running until you are instructed to shut them down at the end of this lab notes answer the Investigation 1 question.|}}

===Investigation 21: How do you create an archive file?===

{{Admon/important | Warning! | Don#Boot up your 't miss the '''.fedora3''' at the end of the <code>tar</code> commands below! It specifies what should go into the archive: the contents of the current directoryVM.}}

{{Admon/important | Warning! | Don't miss the '''.''' at the end of the <code>tar</code> commands below! It specifies what should go into the archive: the contents of the current directory.}} <ol> <li value="4">What do the options c, v, and f mean?</li> <li>Record the archive file size.</li> <li>Compress the file using <code>gzip</code>: <ul> <li><code>gzip /tmp/archive1.tar</code></li> </ul> </li> <li>Record the archive file size after compression.</li> <li>Make sure you're still in <code>/usr/share/doc/sudo*</code> and then create a compressed archive:<ul> <li><code>tar cvzf /tmp/archive2.tgz .</code></li> </ul> </li> <li>What does the <code>z</code> option do?</li> <li>Compare the sizes of <code>/tmp/archive1.tar.gz</code> and <code>/tmp/archive2.tgz</code>. Why are they so close in size?</li></ol> '''Answer the Investigation 2 question1 observations / questions in your lab log book.'''

===Investigation 32: How do you restore files from an archive?==={{Admon/note|Use Remain in your fedora3VM|Perform these steps in the '''fedora3''' virtual machine.}}#Create the directory <code>/tmp/extract1</code> and make it #Change to the <code>/tmp/extract1</code> directory.#Move the file archive1.tar.gz to your current working directory (change into that directory).

#*<code>gunzip /tmp/archive1.tar.gz</code>

#*<code>tar xvf /tmp/archive1.tar</code>

#Create the directory <code>/tmp/extract2</code> and make it your current working #Move the file archive2.tgz to the <code>/tmp/extract2</code> directory.

#*<code>tar xvzf /tmp/extract2/archive2.tgz</code>

'''Answer the Investigation 2 observations / questions in your lab log book.'''  ===Investigation 3: How do you build software from source code?=== Now that you know how to create and decompress "zipped tarball archives", we will demonstrate how to install applications from websites containing these types of archives. Although this method is not as "user-friendly" as using the yum or rpm command, this method is useful if the application is NOT contained in regular software repositories...{{Admon/note|Use fedora2|Perform these steps in the '''fedora2''' virtual machine.}} In order to build software from source code, you must have the appropriate software development tools (such as make and gcc) and libraries (such as GTK) installed. The required tools will vary depending on the computer languages used in the software being built. #Boot up your '''fedora2''' 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> {{Admon/note|Installing Development Libraries|In the future, remember the above procedure whenever installing software from source. Sometimes, you need to install additional tools or libraries in order to compile a particular software package}} <ol> <li value="3">Go to the directory <code>/tmp</code></li> <li>Use the <code>wget</code> command to download the "tar ball" that contains the source code for the NLED text editor. <code>wget</code> is a command-line tool to download files from the web using the http or ftp protocols. <ul> <li><code>wget http://cdot.senecac.on.ca/software/nled/nled_2_52_src.tgz</code></li> </ul> </li> <li>Extract the files. Change to the newly-extracted directory (<code>/tmp/nled-2.52</code>)</li> <li>Check to see if there is a file named <code>configure</code>. If so, run it; if not, skip this step. (Most but not all source code archives contain this file)</li> <li>Check to see if there is a file named <code>Makefile</code> or <code>makefile</code>. If so, type the command: <ul> <li><code>make</code></li> </ul> <li>What does <code>make</code> do?</li> <li>Some software distributed as source code can automatically install itself. Try this command: <ul> <li><code>make install</code></li> </ul> </li> <li>Most but not all source code archives include the capability of installing themselves this way.</li> <li>If the command <code>make install</code> does not work (how can you tell?), copy the <code>nled</code> program manually: <ul> <li><code>cp nled /usr/local/bin</code></li> </ul> </li> <li>Test <code>nled</code> to make sure it works.</li></ol> '''Answer the Investigation 3 questionobservations / questions in your lab log book.''' ==Managing Run-Levels and System Services== ===Investigation 4: How do we Manage Runlevels?=== {{Admon/note|Use fedora2|Perform these steps in the '''fedora2''' virtual machine.}} 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=target</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: <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> '''Answer the Investigation 4 observations / questions in your lab log book.''' === Investigation 5: How do we Manage System Services? === {{Admon/note|Remain in your fedora2 VM|Perform these steps in the '''fedora2''' virtual machine.}} 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, we will learn how to '''control services, and turn off those services that we think are not necessary to help reduce security risks'''.}}

==Investigation 4<ol> <li>Issue the following Linux command: How do you build software from source <ul> <li><code?=>systemctl list-units --type=service</code></li> </ul> </li> <li>Note the services that are currently running.</li> <li>Refer to the tutorial ([[init vs systemd]] ) to learn how to use the systemctl command to stop the service named '''iptables'''</li> <li>Issue the systemctl command to verify that this service has stopped.</li> <li>If you reboot now - the iptables service will be turned back on. We don't want it on though, it causes students headaches. To turn it off permanently we need to disable the service. Refer to the tutorial ([[init vs systemd]] ) to learn how to use the systemctl command to disable the service named '''iptables'''</li> <li>Reboot and confirm that it's no longer running.</li></ol>

{{Admon'''Answer the Investigation 5 observations /note|Compiling requires the correct tools to be installed. | In order to build software from source code, you must have the appropriate software development tools (such as make and gcc) and libraries (such as GTK) installed. The required tools will vary depending on the computer languages used questions in the software being builtyour lab log book.}}'''

#Go to ==Completing the directory <code>/tmp</code>#Use the <code>wget</code> command to download the "tar ball" that contains the source code for the NLED text editor.#*<code>wget http://cdot.senecac.on.ca/software/nled/nled_2_52_src.tgz</code>#Extract the files. Change to the newly-extracted directory (<code>/tmp/nled-2.52</code>)#Check to see if there is a file named <code>configure</code>. If so, run it; if not, skip this step. (Most but not all source code archives contain this file)#Check to see if there is a file named <code>Makefile</code> or <code>makefile</code>. If so, type the command:#*make#*{{Admon/important |Software Development Tools Required |You may need to install <code>gcc</code> (GNU C Compiler) and <code>ncurses-devel</code> (Development Library) in order to complete this step successfully. Use <code>yum</code> to install these packages if you get an error message saying the cc command was not found or the ncurses library is not found.}} Lab==

6# Compressed files: <code>/tmp/archive1. Some software distributed as source tar.gz</code can automatically install itself> and <code>/tmp/archive2. Try this command:tgz</code>#<code>nled</code> application is installed#Lab5 notes how to use systemctl commands make install#VMs backed-up

cp nled #What is the advantage of disabling services such as bluetooth?#What is the difference between a .tgz file and a .tar.gz file? What do these stand for?#What is the purpose of a repository?#What is source code?#How do you build software from source code?#Which is preferred: installing from an RPM file, or installing from source code? Why?#How do you use <code>systemctl</usr/local/bincode> to:#*list runlevel#*list services#*stop a service#*start a service#*Why is it important to learn how to manage services?#*Why is it important to stop certain services?

Answer the Investigation 4 question{{Admon/important | Backup your work |Backup your disk images for fedora2 and fedora3 Virtual Machines.}}