Difference between revisions of "OPS235 Lab 5 - Fedora17"

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[[Category:OPS235]]{{Draft}}
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[[Category:OPS235]]
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=OPS235 Lab 5 - Archiving Files, Compiling Software Packages from Source, Managing Services=
+
 
 +
{{Admon/caution|Draft Lab|This lab has NOT been released for regular distribution. When the lab is ready to be released, this caution banner will disappear.}}
 +
 
 +
=Archiving Files, Compiling Software Packages from Source, Managing Services=
 
[[Category:OPS235]][[Category:OPS235 Labs]]
 
[[Category:OPS235]][[Category:OPS235 Labs]]
  
Line 6: Line 9:
 
==Overview==
 
==Overview==
  
−
* In this lab, you are going to help conserve disk space by learning how to compress and decompress files that are stored your computer server. In addition, you will alternative methods of how to install programs (via git, and decompressing zipped tarball archives and then compiling source code).
+
* 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").
 
* 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").
−
 
  
 
==Objectives==
 
==Objectives==
Line 19: Line 21:
  
  
−
==Required Materials (Bring to All Labs)==
+
== Required Materials (Bring to All Labs) ==
  
−
* '''Fedora 16 LIVE CD''' - You can burn this onto a CD-R in the Open Lab
+
* Fedora 17 LIVE CD
−
* '''Fedora 16 x_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).
+
* Fedora 17 x86_64 Installation DVD
−
* '''SATA Hard Disk''' (in removable disk tray)
+
* SATA Hard Disk (in removable disk tray)
−
* '''USB Memory Stick''' (minimum 64M)
+
* USB Memory Stick
−
* '''Lab Logbook (Lab5 Reference Sheet)''' (to make notes and observations).
+
* Lab Logbook
  
 
==Prerequisites==
 
==Prerequisites==
Line 41: Line 43:
 
|- valign="top"
 
|- valign="top"
 
|
 
|
−
*[http://linuxmanpages.com/man8/tar.8.php tar]
+
*[http://linuxmanpages.com/man1/tar.1.php tar]
−
*[http://linuxmanpages.com/man8/giz.8.php gzip]
+
*[http://linuxmanpages.com/man1/gzip.1.php gzip]
−
*[http://linuxmanpages.com/man8/gunzipiz.8.php gunzipzip]
+
*[http://linuxmanpages.com/man1/gunzip.1.php gunzipzip]
−
*[http://linuxmanpages.com/man8/make.8.php make]
+
*[http://linuxmanpages.com/man1/make.1.php make]
−
*[http://schacon.github.com/git/git.html git]
 
 
|
 
|
 
*[http://www.linuxcertif.com/man/1/systemctl/ systemctl]  
 
*[http://www.linuxcertif.com/man/1/systemctl/ systemctl]  
Line 56: Line 57:
 
* [http://www.centos.org/docs/2/rhl-gsg-en-7.2/s1-zip-tar.html archiving with tar, gzip, gunzip]
 
* [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]
 
* [http://www.tuxfiles.org/linuxhelp/softinstall.html Compiling Software from Source Code]
−
* [http://schacon.github.com/git/everyday.html Using git]
 
 
* [[init vs systemd]]
 
* [[init vs systemd]]
−
 
  
 
==Archiving Files / Compiling Software from Source Code==
 
==Archiving Files / Compiling Software from Source Code==
Line 69: Line 68:
 
{{Admon/note|Use fedora3|Perform these steps in the '''fedora3''' virtual machine.}}
 
{{Admon/note|Use fedora3|Perform these steps in the '''fedora3''' virtual machine.}}
  
−
#Boot up your '''fecora3''' VM.
+
#Boot up your '''fedora3''' VM.
 
#Change your working directory to <code>/usr/share/doc/sudo*</code>
 
#Change your working directory to <code>/usr/share/doc/sudo*</code>
 
#Use the tar (tape archiver) command to create an archive file named <code>/tmp/archive1.tar</code>
 
#Use the tar (tape archiver) command to create an archive file named <code>/tmp/archive1.tar</code>
Line 94: Line 93:
 
</ol>
 
</ol>
  
 +
'''Answer the Investigation 1 observations / questions in your lab log book.'''
  
 
===Investigation 2: How do you restore files from an archive?===
 
===Investigation 2: How do you restore files from an archive?===
Line 113: Line 113:
 
#Repeat the previous command, leaving out the option "z". Does it work? Why?
 
#Repeat the previous command, leaving out the option "z". Does it work? Why?
 
#Compare the <code>README</code> file in this directory with the original file. Are they exactly the same?
 
#Compare the <code>README</code> file in this directory with the original file. Are they exactly the same?
 +
 +
'''Answer the Investigation 2 observations / questions in your lab log book.'''
  
  
Line 118: Line 120:
  
 
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...
 
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.}}
 
{{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.
 
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.
  
−
# Issue the following command to install a basic set of development tools and libraries:<br /><br /> <code>yum groupinstall "Development Tools" "Development Libraries"</code>.
+
#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}}
 
{{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}}
  
−
#Go to the directory <code>/tmp</code>
+
<ol>
−
#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.
+
  <li value="3">Go to the directory <code>/tmp</code></li>
−
#*<code>wget http://cdot.senecac.on.ca/software/nled/nled_2_52_src.tgz</code>
+
  <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.
−
#Extract the files. Change to the newly-extracted directory (<code>/tmp/nled-2.52</code>)
+
    <ul>
−
#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><code>wget http://cdot.senecac.on.ca/software/nled/nled_2_52_src.tgz</code></li>
−
#Check to see if there is a file named <code>Makefile</code> or <code>makefile</code>. If so, type the command:
+
    </ul>
−
#*<code>make</code>
+
  </li>
−
#What does <code>make</code> do?
+
  <li>Extract the files. Change to the newly-extracted directory (<code>/tmp/nled-2.52</code>)</li>
−
#Some software distributed as source code can automatically install itself. Try this command:
+
  <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>
−
#*<code>make install</code>
+
  <li>Check to see if there is a file named <code>Makefile</code> or <code>makefile</code>. If so, type the command:
−
#Most but not all source code archives include the capability of installing themselves this way.
+
    <ul>
−
# If the command <code>make install</code> does not work (how can you tell?), copy the <code>nled</code> program manually:
+
      <li><code>make</code></li>
−
#*<code>cp nled /usr/local/bin</code>
+
    </ul>
−
#Test <code>nled</code> to make sure it works.
+
  <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 observations / questions in your lab log book.'''
  
−
===Investigation 4: Using git===
+
==Managing Run-Levels and System Services==
  
−
{{Admon/note|Use fedora3|Perform these steps in the '''NAME''' virtual machine.}}
+
===Investigation 4: How do we Manage Runlevels?===
  
−
#Insert Lab investigation instructions here.
+
{{Admon/note|Use fedora2|Perform these steps in the '''fedora2''' virtual machine.}}
  
−
==Managing System Services==
+
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>
  
−
===Investigation 5: How do we Manage Runlevels and System Services?===
+
'''Answer the Investigation 4 observations / questions in your lab log book.'''
  
−
{{Admon/note|Use fedora2|Perform these steps in the '''fedora2''' virtual machine.}}
+
=== Investigation 5: How do we Manage System Services? ===
  
−
{{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, we will learn how to control services, and turn off those that we think are not necessary.}}
+
{{Admon/note|Remain in your fedora2 VM|Perform these steps in the '''fedora2''' virtual machine.}}
  
−
#Determine your current runlevel using the <code>runlevel</code> command.
+
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'''.}}
−
#Change to the appropriate startup directory 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 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'' 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 off.
 
  
−
You can find out some basic information about a particular service by querying <code>rpm</code> for information about the package that installed the service file in <code>/etc/rc.d/init.d</code>. For example, to find out about the <code>cups</code> service, execute: <code>rpm -qif /etc/rc.d/init.d/cups</code>
+
<ol>
−
}}
+
  <li>Issue the following Linux command:
 +
      <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>
  
 +
'''Answer the Investigation 5 observations / questions in your lab log book.'''
  
 
==Completing the Lab==
 
==Completing the Lab==
Line 191: Line 223:
 
Arrange evidence for each of these items on your screen, then ask your instructor to check each item:
 
Arrange evidence for each of these items on your screen, then ask your instructor to check each item:
  
−
#[ ] <code>/tmp/fstest</code> filesystem counted with files copied to it.
+
# Compressed files: <code>/tmp/archive1.tar.gz</code> and <code>/tmp/archive2.tgz</code>
−
#[  ] <code>nled</code> is installed
+
#<code>nled</code> application is installed
−
#[  ] Correct services are disabled
+
#Lab5 notes how to use systemctl commands
−
#[  ] <code>/lab5</code> has an entry in <code>/etc/fstab</code>
+
#VMs backed-up
  
−
==Preparing for the Quizzes==
+
==Preparing for Quizzes==
  
 
#What is the advantage of disabling services such as bluetooth?
 
#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 difference between a .tgz file and a .tar.gz file? What do these stand for?
−
#How do you ensure that a filesystem is mounted every time the system is started?
+
#What is the purpose of a repository?
−
#How is creating and using a filesystem in a file different from creating and using a filesystem in a block device (such as a partition)?
 
 
#What is source code?
 
#What is source code?
 
#How do you build software from source code?
 
#How do you build software from source code?
 
#Which is preferred: installing from an RPM file, or installing from source code? Why?
 
#Which is preferred: installing from an RPM file, or installing from source code? Why?
−
#How do you use <code>chkconfig</code>?
+
#How do you use <code>systemctl</code> to:
−
#The startup directory for each runlevel contains symbolic links. Where are the targets of the symbolic links?
+
#*list runlevel
−
#When you use the menu option System>Administration>Services, what program is run?
+
#*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?
 +
 
  
 
{{Admon/important | Backup your work |Backup your disk images for fedora2 and fedora3 Virtual Machines.}}
 
{{Admon/important | Backup your work |Backup your disk images for fedora2 and fedora3 Virtual Machines.}}

Latest revision as of 19:48, 3 January 2014


Stop (medium size).png
Draft Lab
This lab has NOT been released for regular distribution. When the lab is ready to be released, this caution banner will disappear.

Archiving Files, Compiling Software Packages from Source, Managing Services


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").

Objectives

  1. To create and use archive files (tar and tar.gz)
  2. Compiling software packages from source code
  3. Install an application from software development repositories using the bit utility
  4. Customising file-system start-up


Required Materials (Bring to All Labs)

  • Fedora 17 LIVE CD
  • Fedora 17 x86_64 Installation DVD
  • SATA Hard Disk (in removable disk tray)
  • USB Memory Stick
  • Lab Logbook

Prerequisites

  • Completion and Instructor "Sign-off" of Lab 4: OPS235 Lab 4


Linux Command Online Reference

Each Link below displays online manpages for each command (via http://linuxmanpages.com):

Archiving Utilities: Service Management Utilities:


Resources on the web

Additional links to tutorials and HOWTOs:

Archiving Files / Compiling Software from Source Code

Archive files are often used to contain source code for software; in this lab you will also be compiling software from a source code archive.

Note.png
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.

Investigation 1: How do you create an archive file?

Note.png
Use fedora3
Perform these steps in the fedora3 virtual machine.
  1. Boot up your fedora3 VM.
  2. Change your working directory to /usr/share/doc/sudo*
  3. Use the tar (tape archiver) command to create an archive file named /tmp/archive1.tar
    • tar cvf /tmp/archive1.tar .
Important.png
Warning!
Don't miss the . at the end of the tar commands below! It specifies what should go into the archive: the contents of the current directory.
  1. What do the options c, v, and f mean?
  2. Record the archive file size.
  3. Compress the file using gzip:
    • gzip /tmp/archive1.tar
  4. Record the archive file size after compression.
  5. Make sure you're still in /usr/share/doc/sudo* and then create a compressed archive:
    • tar cvzf /tmp/archive2.tgz .
  6. What does the z option do?
  7. Compare the sizes of /tmp/archive1.tar.gz and /tmp/archive2.tgz. Why are they so close in size?

Answer the Investigation 1 observations / questions in your lab log book.

Investigation 2: How do you restore files from an archive?

Note.png
Remain in your fedora3 VM
Perform these steps in the fedora3 virtual machine.
  1. Create the directory /tmp/extract1
  2. Change to the /tmp/extract1 directory.
  3. Move the file archive1.tar.gz to your current directory.
  4. Unzip the first archive you created:
    • gunzip archive1.tar.gz
  5. Extract the files from the first archive:
    • tar xvf archive1.tar
  6. Are all the files there?
  7. Compare /tmp/extract1/README and /usr/share/doc/sudo*/README. Are they exactly the same? Why?
  8. Create the directory /tmp/extract2
  9. Move the file archive2.tgz to the /tmp/extract2 directory.
  10. Extract the files from the second archive:
    • tar xvzf /tmp/extract2/archive2.tgz
  11. Note that this time a separate gunzip command was not needed. Why?
  12. Repeat the previous command, leaving out the option "z". Does it work? Why?
  13. Compare the README file in this directory with the original file. Are they exactly the same?

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...

Note.png
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.

  1. Boot up your fedora2 VM.
  2. Issue the following command to install a basic set of development tools and libraries:
    yum groupinstall "Development Tools" "Development Libraries"
Note.png
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
  1. Go to the directory /tmp
  2. Use the wget command to download the "tar ball" that contains the source code for the NLED text editor. wget is a command-line tool to download files from the web using the http or ftp protocols.
  3. Extract the files. Change to the newly-extracted directory (/tmp/nled-2.52)
  4. Check to see if there is a file named configure. If so, run it; if not, skip this step. (Most but not all source code archives contain this file)
  5. Check to see if there is a file named Makefile or makefile. If so, type the command:
    • make
  6. What does make do?
  7. Some software distributed as source code can automatically install itself. Try this command:
    • make install
  8. Most but not all source code archives include the capability of installing themselves this way.
  9. If the command make install does not work (how can you tell?), copy the nled program manually:
    • cp nled /usr/local/bin
  10. Test nled to make sure it works.

Answer the Investigation 3 observations / questions in your lab log book.

Managing Run-Levels and System Services

Investigation 4: How do we Manage Runlevels?

Note.png
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.

  1. Issue the following Linux command:
    • systemctl list-units --type=target
  2. Note the target labelled graphical. Now trace the chain of links starting at /etc/systemd/system/default.target - what's it ultimately pointing to?
  3. Issue the following commands to switch the default mode (also known as target, formerly runlevel):
    • rm /etc/systemd/system/default.target
    • ln -s /lib/systemd/system/multi-user.target /etc/systemd/system/default.target
  4. Restart your fedora2 VM. What happens?
  5. Log into your regular user account.
  6. Issue the following Linux command:
    • startx
  7. What happens?
  8. Log-off your graphical system. You should return to your shell prompt.
  9. Issue the following commands:
    • rm /etc/systemd/system/default.target
    • ln -s /lib/systemd/system/graphical.target /etc/systemd/system/default.target
  10. Reboot your fedora2 VM. What Happens?

Answer the Investigation 4 observations / questions in your lab log book.

Investigation 5: How do we Manage System Services?

Note.png
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.}}

  1. Issue the following Linux command:
    • systemctl list-units --type=service
  2. Note the services that are currently running.
  3. Refer to the tutorial (init vs systemd ) to learn how to use the systemctl command to stop the service named iptables
  4. Issue the systemctl command to verify that this service has stopped.
  5. 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
  6. Reboot and confirm that it's no longer running.

Answer the Investigation 5 observations / questions in your lab log book.

Completing the Lab

Arrange evidence for each of these items on your screen, then ask your instructor to check each item:

  1. Compressed files: /tmp/archive1.tar.gz and /tmp/archive2.tgz
  2. nled application is installed
  3. Lab5 notes how to use systemctl commands
  4. VMs backed-up

Preparing for Quizzes

  1. What is the advantage of disabling services such as bluetooth?
  2. What is the difference between a .tgz file and a .tar.gz file? What do these stand for?
  3. What is the purpose of a repository?
  4. What is source code?
  5. How do you build software from source code?
  6. Which is preferred: installing from an RPM file, or installing from source code? Why?
  7. How do you use systemctl 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?


Important.png
Backup your work
Backup your disk images for fedora2 and fedora3 Virtual Machines.
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