Changes

In this lab, you are going to help identify potential problems such as not properly compressing VM image files when backing up VMs, or forgetting your root password. You will also learn to conserve hard 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 applications (i.e. programs).

#Creating *Learn to troubleshoot some common problems after installing VMs*Create and using extract '''archive ''' files (tar and tar.gz)#Compiling software packages from source code#*Install applications using various methods:::*Decompressing source code '''Download''', '''decompress''' and archivefile from the Internet, and compiling then '''compile source code''' in order to install an application.::*Use '''yum ''' utility to install software from '''local source programs ''' (on DVD drive)::*Use '''yum ''' utility to install software from '''repositories ''' (online storage areas):*Learn how to '''add repositories''' (online software storage areas) to install less common applications.<olul><li value="4">Demonstrating Demonstrate the use of Bash Shell scripts to automate routine tasks(generate a customized software report)</li></olul>

==Minimum Required Materials / Lab Preparation==

[http://linuxmanpagesman7.comorg/linux/man-pages/man1/tar.1.php html tar]<br>

[http://linuxmanpagesman7.comorg/linux/man-pages/man1/make.1.php html make]

|width="40%" |{{Admon/tip|Online Linux Command Review|The following links tutorial will allow you to practice Linux commands that you learned from ULI101learn essential shell scripting skills:<ul> <li>Bash Shell Scripting ContinuedBasics - Part 4 (The sed Utility): [ ]<br>'''/home/murray.saul/scripting-4'''</li></ul>|

= INVESTIGATION 1: ARCHIVING FILES TROUBLESHOOTING AFTER VM INSTALLS & BACKUPS ={| width="50%" align="right" cellpadding="10"|- valign="top"|[[Image:grub1.png|thumb|right|600px|Press '''e''' at Grub Boot Menu to edit]]|}There are a few "classic problems" that students can encounter with their virtual machines and their host machine after performing lab2. Although all OPS235 students may not encounter these problems, it is good to be aware of what a potential problem may look like, and know how to solve that problem.  '''A few common problems are:''' *I Can't boot into Graphical Mode on my '''c7host''' machine*I Forgot My '''Regular User''' Password*I Forgot My '''root''' Password*I Can't Start My Virtual Machine*I Can't start my Host machine   '''Troubleshooting consists of 3 basic elements:''' *'''Asking Questions''' (eg. what was done recently prior to problem?)*'''Eliminating''' what the problem '''IS NOT'''*'''Tenacity''' and '''patience''' (ability to focus on finding the cause of the problem)   If you cannot log graphically into your machine (first 3 common problems), there is a trick to boot your system into '''single-user''' mode. This mode does not provide networking, graphics, or logging in as other regular users, but can connect to a text-based interface as the '''root''' user. This method will only work if a GRUB (<u>'''Gr'''</u>and '''<u>U</u>'''nified <u>'''B'''</u>oot-loader) password has not been set, or that you haven't forgotten the GRUB password.   '''Steps to Boot into "Single-User Mode":''' {| width="50%" align="right" cellpadding="10"|- valign="top"|[[Image:grub2_1.png|thumb|right|600px|Add the boot option '''single''' and then press '''ctrl-x''' to boot into single user mode]]|}#Boot-up your '''centos1''' VM. '''when the Grub Boot menu appears''', press the letter <b><code><span style="color:#3366CC;font-size:1.2em;">e</span></code></b> (for "edit").#Using your arrow keys, scroll to next screen to '''linux''' or '''linux-efi''' command and type the word <b><code><span style="color:#3366CC;font-size:1.2em;">single</span></code></b> as an argument after '''quiet''' (see diagram for reference) and then press <b><code><span style="color:#3366CC;font-size:1.2em;">ctrl-x</span></code></b> to boot.#The system should boot into text-based mode. Enter your '''root''' password.#One thing to look at is partition space usage. Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">df -h</span></code></b>#If you notice 0% free space in the '''/''' partition, then there is a problem. This most likely is caused by not following steps to create a <u>compressed</u> copy of the VM image. If that is the case, locate the large image backup and remove it. Do NOT remove the image in ''/var/lib/libvirt/images'' directory!#You can use the '''passwd''' command to reset your '''regular user''' password (eg. <b><code><span style="color:#3366CC;font-size:1.2em;">passwd regularuserid</span></code></b>). You can press '''ctrl-c''' if you wish to abort (i.e. not change password).#To restart in graphical mode, simply enter the command <b><code><span style="color:#3366CC;font-size:1.2em;">reboot</span></code></b>. :Unfortunately, this method does not work if you forgot your '''root''' password (To reset your root password, refer to procedure below).  '''Steps to Reset Root's Password:''' {| width="50%" align="right" cellpadding="10"|- valign="top"|[[Image:grub2_3.png|thumb|right|600px|Add '''rw init=/sysroot/bin/sh''' as shown and then press '''ctrl-x''' to boot into single user no root password mode]]|}#The procedure to reset root's password is different than shown above. Press <b><code><span style="color:#3366CC;font-size:1.2em;">e</span></code></b> at the Grub boot menu.#Using your arrow keys, move to '''linux''' or '''linux-efi''' command and replace the argument '''ro''' with the argument <b><code><span style="color:#3366CC;font-size:1.2em;">rw init=/sysroot/bin/sh</span></code></b> (see diagram for reference) and then press <b><code><span style="color:#3366CC;font-size:1.2em;">ctrl-x</span></code></b> to boot.#The system should boot into text-based mode without prompting for root's password.#Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">chroot /sysroot</span></code></b><br><br>#Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">passwd root</span></code></b> in order to change your root password (press '''ctrl-c''' if you wish to abort - i.e. not change password).#To restart in graphical mode, simply enter the command <b><code><span style="color:#3366CC;font-size:1.2em;">reboot</span></code></b>.

 '''Catastrophic Boot Problems:''' :Not being able to start your '''c7host''' due to '''Kernel Panic''' or some sort of '''catastrophic disk failure''' is not as easy to fix. You might be able to boot from your '''Centos LIVE DVD, open a terminal and mount the partition''' via command line and look for possible problems (setup files like '''/etc/fstab'''). '''Lab5''' will discuss more about mounting and the /etc/fstab file. The "worst-case scenario" would be to purchase a new hard disk, '''perform lab1 completely, perform lab2 to install and set-up virtualization software''', then '''restore your VM image and xml file backups''' (eg. decompressing images, issuing virsh define commands for .xml files). That is why consistently '''performing backups of ALL of your VMS at the end of each lab is absolutely essential! You have been warned!''' = INVESTIGATION 2: ARCHIVING FILES = ==Part 1: Creating a File Archive==={{Admon/note|Use centos3|Perform these steps in the '''centos3''' virtual machine.}}

#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>'''#*<b><code><span style="color:#3366CC;font-size:1.2em;">tar cvf /tmp/archive1.tar .</span></code></b>

{| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{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.}}

<li value="4">What do the options '''c''', '''v''', and '''f ''' mean?</li>

<li>Compress the file using <code>'''gzip</code>''':

<li><b><code><span style="color:#3366CC;font-size:1.2em;">gzip /tmp/archive1.tar</span></code></b></li>

<li>Make sure you're still in <code>'''/usr/share/doc/sudo*</code> ''' and then create a compressed archive:

<li><b><code><span style="color:#3366CC;font-size:1.2em;">tar cvzf /tmp/archive2.tgz .</span></code></b></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>

{{Admon/note|#Remain in your centos3 VM|Perform these steps in the '''centos3''' virtual machineVM.}}#Create the directory <code>'''/tmp/extract1</code>'''#Change to the <code>'''/tmp/extract1</code> ''' directory.#Move the file '''archive1.tar.gz ''' to your current directory.

#*<b><code><span style="color:#3366CC;font-size:1.2em;">gunzip archive1.tar.gz</span></code></b>

#*<b><code><span style="color:#3366CC;font-size:1.2em;">tar xvf archive1.tar</span></code></b>

#Compare <code>'''/tmp/extract1/README</code> ''' and <code>'''/usr/share/doc/sudo*/README</code>'''. Are they exactly the same? Why?#Create the directory <code>'''/tmp/extract2</code>'''#Move the file '''archive2.tgz ''' to the <code>'''/tmp/extract2</code> ''' directory.

#*<b><code><span style="color:#3366CC;font-size:1.2em;">tar xvzf /tmp/extract2/archive2.tgz</span></code></b>#Note that this time a separate <b><code><span style="color:#3366CC;font-size:1.2em;">gunzip</span></code></b> command was not needed. 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?

'''Answer the Investigation Part 2 observations / questions in your lab log book.'''

===Part 3: Practical Application - Compiling Source Code from Archive File==={| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{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}}

# Part is to be performed in your '''centos2''' VM.# Issue the following command to install a basic set of development tools and libraries:<br /><b><code><span style="color:#3366CC;font-size:1.2em;">yum groupinstall "Development Tools" "Development Libraries"</span></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}}b><br><br>

<li value="3">Go to the directory <code>'''/tmp</code>'''</li> <li>Use the <b><code><span style="color:#3366CC;font-size:1.2em;">wget</span></code></b> 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><b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">wget http://cdot.senecac.on.ca/software/nled/nled_2_52_src.tgz</span></code></b></li>

<li>Extract the files. Change to the newly-extracted directory (<b><code><span style="color:#3366CC;font-size:1.2em;">/tmp/nled-2.52</span></code></b>)</li> <li>Check to see if there is a file named <b><code><span style="color:#3366CC;font-size:1.2em;">configure</span></code></b>. 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 <b><code><span style="color:#3366CC;font-size:1.2em;">Makefile</span></code></b> or <b><code><span style="color:#3366CC;font-size:1.2em;">makefile</span></code></b>. If so, type the command:

<li><b><code><span style="color:#3366CC;font-size:1.2em;">make</span></code></b></li> <li>Did the command work? Why? Use the <b><code><span style="color:#3366CC;font-size:1.2em;">yum</span></code></b> command to install the package '''gcc'''. What do you think the package ''gcc'' does?</li>

<li>Reissue the <b><code><span style="color:#3366CC;font-size:1.2em;">make</span></code></b> command. Where you successful? What does <code>make</code> do?</li> <li>Issue the command as root: <b><code><span style="color:#3366CC;font-size:1.2em;">yum list ncurses</span></code></b>. What do you see? Issue the command at root: <b><code><span style="color:#3366CC;font-size:1.2em;">yum search ncurses</span></code></b>. What do you observe?</li> <li>In this case, you need to install the ncurses development libraries as well. Issue the following command as root: <b><code><span style="color:#3366CC;font-size:1.2em;">yum install ncurses-devel.x86_64</span></code></b>. Now issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">make</span></code></b></li>

<li><b><code><span style="color:#3366CC;font-size:1.2em;">make install</span></code></b></li>

<li>If the command <code>make install</code> does not work (how can you tell? What command did you learn from ULI101 to confirm that this command cannot be run from the command line?), copy the <b><code><span style="color:#3366CC;font-size:1.2em;">nled</span></code></b> program manually:

<li><b><code><span style="color:#3366CC;font-size:1.2em;">cp nled /usr/local/bin</span></code></b></li>

<li>Test Run <b><code><span style="color:#3366CC;font-size:1.2em;">nled</span></code> </b> from the current directory to make sure that it works. To exit this application, press '''ESC''', then type the letter '''q''' at the command prompt as the bottom left-hand corner and then press '''ENTER'''.</li> <li>Why did copying the nled executable to '''/usr/local/bin ''' allow the nled command to be run by name anywhere in the command prompt?</li>

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

=INVESTIGATION 23: Using the Yum Command for Local & Repository Installs=

RPM maintains a database of installed software. This information is very useful to system administrators. In the previous lab you queried that database using RPM == Manage Software and Repositories with the -q argument. When you query the RPM database, you can separately specify::* Do an <u>operational task</u> on one or more packages (like installing or removing a package), using a '''select-option''':* What <u>information</u> you want about those packages, using a '''query-option'''Yum ==

(Perform investigations 1 {| width="40%" align="right" cellpadding="10"|- 3 in your host machine (c6host)valign="top"|colspan="2"|{{Admon/note|Internet Connection|In order for yum to work you require a connection to the Internet. Establish this connection by using the browser to log into SeneNET}}

|}# Using information from Perform this section in your '''c7host''' machine.#Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum install elinks</span></code></b>#Now issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum info elinks</span></code></b>#How can you tell if the elinks package has been installed?#To remove the elinks package issue the man page for command: <b><code>rpm<span style="color:#3366CC;font-size:1.2em;">yum remove elinks</span></code></b># Verify that the elinks package has been removed. Also verify that the application called: '''xchat''' is not installed.# Place your Centos7 Full Install DVD into the DVD drive of your hostmachine.# View the contents of the DVD drive using the file manager application (called '''nautilus'''). Change to the Packages subdirectory. What does this subdirectory contain?# Use a graphical file manager to view the contents of the DVD in your machine.<br><br>'''TIP:''' If you are having problems locating pathname to your DVD, open a terminal, login as '''root''', issue the command: '''mount''', fill and look for a path-name containing your Centos Install DVD and use that path-name when required later in this informationsection.<br><br># Open a shell terminal and use the Linux command '''cd''' to change to the '''Packages''' sub-directory (hint:similar path-name as USB, but use '''Centos 7 x86_64/Packages''' and use '''quotes''' " " around full path-name since there are spaces within the pathname).

== Part 2: How do you :* '''yum localinstall''' (install rpm files located from the machine via downloads to hard-drive, DVD, etc)::* '''yum install''' (install and remove software with RPM? ==applications from an online repository)

<ol> <li value="11">Within the '''Packages''' subdirectory of the '''Centos7 Full Install DVD''', locate the '''rpm''' file that contains the '''xchat'''Answer application (note the full path-name of the Investigation 2 observations file). What do you think is the purpose of the numbers also contained in the filename?</ questions in your lab log bookli> <li>Issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">yum localinstall "full_pathname_to_xchat_rpm_file"</span></code></b></li> <li>Verify that the '''xchat''' command has been installed.</li></ol>

{| width="40%" align= Part 3: How do you install and remove software with ''yum''? "right" cellpadding="10"|- valign="top" |colspan="2"|{{Admon/notetip|IRCs: A Great Tool for Linux Administrators|Although Search Engines (like Google) are a system administrator's good friend, Internet Connection|In order Relay Chats (IRCs) are also a great tool for yum system administrators to help obtain information. Many website offer information on how to work you require a connection connect to the InternetIRCs (both nodes (eg. FreeNode) and irc channel (eg. #linux). Establish this connection by using the browser <br><br><u>'''A few tips to log into SeneNETconsider with IRCs'''</u>:<ul><li>Do your Homework (read docs first!)</li><li>Ask specific questions</li><li>Not all chats are friendly</li><li>Be patient when asking questions (use courtesy)</li><li>The advise is free (you get what you pay for!)</ul>}} # Change to your home directory.|}

<li value="214">Issue 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 install elinksrepolist</codespan> and answer </code>y</codeb> to the question about installation. <ol type="a"/li> <li>Where did Take a few moments to view the contents of the file. Do you see which repositories are used by the '''yum'' get ' command? Write down the elinks software?repositories in your lab logbook.</li> <li>Why could ''yum'' install elinks when rpm couldn't?View the following link to see a general listing of repositories:<br>[ [http://wiki.centos.org/li> <AdditionalResources/ol> Repositories Available Repositories for Centos] ].</li> <li>Issue an RPM query to verify that elinks is installed. Record To add this repository, issue the command in your lab log:<br><b><code><span style="color:#3366CC;font-size:1.3em;">wget https://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-book6.noarch.rpm</span></code> </lib> <libr>Issue Or if you receive a error message, try the command: <br><b><code><span style="color:#3366CC;font-size:1.3em;">yum remove elinksinstall epel-release</span></code> </b></li> <li>Issue an RPM query to verify that elinks is no longer installedTo enable the repository in yum, issue the following command:<br><b><code><span style="color:#3366CC;font-size:1. Record this command in your lab log3em;">yum install epel-release-7-book6.noarch.rpm</span></code></b></li> <li>Issue this 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 info cupsclean all</span></code></b></li></olli>::* Based on To verify that you have added the resultrepository, do you think that cups is a useful package for your system? If not, try removing it.can issue the command: <b><olcode> <li valuespan style="8color:#3366CC;font-size:1.3em;">yum repolist</span></code></b></li><li>Unused and unneeded software can present a security risk and ties up disk space needlessly. Find '''at least 4 other packages ''' to remove on your c7host machine(for example: games, '''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>

= INVESTIGATION 3=Automating Routine Tasks (Shell Scripting)=={|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/tip|Bash Shell Scripting Tips:|<br><ul><li>'''The Here Document'''<br><br>A neat little trick involving a special type of redirection of stdin ( '''&lt;&lt;''' ) that allows input to be redirected to a command from within the command. '''The name relates to where the stdin is contained: LOOKING AHEAD =not in a file, but "here in the command itself"'''. A character (like '''+''') is used to mark the boundary of stdin. It is important that the ending boundary only contains a line with that matching character (eg '''+'''); otherwise the stdin will continue to be read! This command is a convenience way to display multiple lines on that screen, but this command can be used with any Linux command that accept stdin.<br><br><u>'''Examples''' (try at the shell prompt)</u><br><br>''cat &lt;&lt;+<br>This is a test message<br>This is the second line<br>+''<br><br>''mail -s "test message" youremailaddr &lt;&lt;+<br>This is a test message<br>I hope you like it.''<br>+<br><br>''tr [a-z] [A-Z] &lt;&lt;+<br>i like ops235<br>i love scripting.<br>+''<br><br></li><li>'''Using sed to Manipulate Text'''<br><br>The Linux command '''sed''' stands for <u>'''S'''</u>treaming <u>'''Ed'''</u>itor which is an effective way to manipulate a text file, output sent from a command, or from within a "here document". This command can manipulate matching text on a variety of criteria (such as line number, regular expression match, etc). Commands can then be used for manipulation such as omitting, printing, substituting, adding, inserting, etc. The sed option -n suppresses display of text so the print (p) command can be used; otherwise, the text will be displayed (with edits via the sed command instructions). Results of text manipulation with sed can be stored in a variable using command substitution, or redirected to a file. NEVER redirect the stdout from a sed command to the same input file (or the input file will be destroyed)! <br><br></li><li>'''<u>Examples''' (try at the shell prompt)</u><br><br>''sed 's/&#124;/ /g' &lt;&lt;+<br>I&#124;like&#124;weekends!<br>+''<br><br>''sed 's/$/\n/g' &lt;&lt;+<br>This text<br>should be<br>double-spaced!''<br>+<br><br></li></ul>}}|}

We will continue the discussion of with using Bash Shell Scripts shell scripts to help automate routine tasks for create a Software Information Report that manipulates output generated by the Linux system administrator'''rpm''' command. In lab1, you were exposed The '''sed''' and '''awk''' commands are very useful tools in shell scripting to downloading and running Bash Shell Scripts for demonstration purposesmanipulate text. Before showing you demos for In this lab, you should learn a few more "shell scripting tricks" in case you need we will be using ''sed'' to allow the user to create your own set of tools for task automationselect certain portions from the rpm command (options -qi).

if [ $#Click on the following link to run an online tutorial showing you some additional shell scripting techniques: [ link -ne 1 ].<br>#It is recommended to practice creating Bash Shell Scripts as you proceed throughout this course.then<br>#Let's look at some demos involving managing VMs with shell scripts. Issue the following &nbsp; echo "Your command:<blockquotemust have a application-name as argument" >&2<bbr><code><span style=&nbsp; echo "pointerUSAGE: $0 [application-events: none;cursor: default;color:#3366CC;name]">wget https://scs.senecac.on.ca/~elizabeth.kopiec/backupVM.bash&2</spanbr>&nbsp; exit 1</codebr>fi</bbr></blockquotebr>&#Set the appropriate permissions and run this Bash Shell script.#Verify that the backup of your virtual machine occurred 35; Create report title (hint: issue ls command echo with -e option allows newline \n character to verify the date and time of creationbe used).#Use the <bbr><code>wget</code></b> command to download, study, and run the following shell scripts onecho -line:<blockquote><b><code><span style=e " pointer-events:none;cursor:default;color:#3366CC;\nSOFTWARE PACKAGE INFORMATION REPORT">https:/root/scs.senecac.on.ca/~murray.saul/vm-startpackage-textinfo.bashtxt <br>https://scs.senecac.on.ca/~murray.saul/vmecho -stop-text.bash</span></code></b><br><b><code><span style=e " pointer-eventsDate:none;cursor$(date +'%A %B %d, %Y (%H:default;color%M:#3366CC;%p)')\n\n ">https:> /root/scs.senecac.on.ca/~murray.saul/vmpackage-startinfo.bashtxt<br>https://scs.senecac.on.ca/~murray.saul/vm-stop.bash</span></code></b></blockquote>#Try to understand what these Bash Shell scripts do.#You have completed lab2. Proceed to Completing The Lab, and follow the instructions for "lab sign-off".

'''Answer all observations </ questions code><ol><li value="6">Save your editing session, but remain in your lab log bookthe text editor.</li><li>The code displayed below uses a trick called the "Here Document" to redirect stdin from within the command (a quick way to display output on the screen). The read command will store the different information report items as words (separated by a space). The sed command used to convert the spaces to pipes (|) and stored into another variable. This allows the sed command to use extended regular expressions to print rpm elements that match those various patterns to be added to the report. Add the following code</li></ol><br><code style="color:#3366CC;font-family:courier;font-size:.9em;">&#35; Clear screen and use Here Document to display select on report items to read into variable<br>clear<br>cat &lt;&lt;+<br>Available Package Information Items:<br><br>Name<br>Summary<br>Version<br>License<br>Source<br>URL<br>+<br>read -p "Enter word(s) shown above separated by spaces: " choice<br><br>&#35; Convert spaces to pipe symbol (|)<br>processedChoice=$(echo $choice | sed 's/ /|/g'')<br><br>&#35; Use sed with extended regular expressions to only print those matching report elements<br>rpm -qi $1 | sed -r -n "/($processedChoice)/ p" &gt;&gt; /root/package-info.txt<br><br>cat &lt;&lt;+<br>File "/root/package-info.txt" has been created<br>+<br></code>

<ol><li value= "8">Save, set permissions, and then run that shell script for the application '''gedit'''. Did it create that report? Try running the script without an argument - What did it do? <li>Use the <b><code>wget</code></b> command to download, study, and run the following shell scripts on-line:<blockquote><b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">https://scs.senecac.on.ca/~murray.saul/packageInfoGraphical.bash</span></code></b></blockquote></li><li>Try to understand what this Bash Shell script does.</li><li>You have completed lab3. Proceed to Completing The Lab, and follow the instructions for "lab =sign-off".</li></ol>

{{Admon'''Answer Investigation 3 observations /important|Time for a new backup!|If you have successfully completed this questions in your lab, make a new backup of your virtual machineslog book.}}'''

'''Notes:'''= LAB 3 SIGN-OFF (SHOW INSTRUCTOR) =# rpm command options# yum command options# How to use pvs/vgs/lvs/df/pvcreate/vgextend{{Admon/lvextend# Answer to important|Time for a new backup!|If you have successfully completed this question "What is the license lab, make a new backup of the nautilus package?"your virtual machines as well as your host machine.}}

'''Arrange evidence for each proof of these items the following on your the screen, then ask your instructor to review them and sign off on the lab's completion:'''# elinks application removed on the host (disk pack - main system c6host).# Unnecessary/unused packages have been deleted (list at least 4, and show that they are no longer installed).# Fresh backup of the virtual machines.

<ol><li><span style="color:green;font-size:1.5em;">&#x2713;</span> '''centos3''' VM:<blockquote><ul><li> '''Archived''' files created</li></ul></blockquote></li><li><span style=Preparing "color:green;font-size:1.5em;">&#x2713;</span> '''c7host''' Machine:<blockquote><ul><li> '''Four unnecessary packages removed'''</li><li> '''xchat''' package installed</li><li> '''One repository added''' for Quizzes=yum</li><li>Creation of your bash shell script called '''packageInfo.bash'''</li></ul></blockquote><li><span style="color:green;font-size:1.5em;">&#x2713;</span> '''Lab3''' log-book filled out.</li></ol>

#What is the advantage purpose of disabling services such as bluetoothbooting into single-user mode?#List steps in order to boot into single-user mode

#How What does yum do you use <code>service/init/chkconfig</code> to:that rpm does not?#*show/set current runlevelList the steps to install a package via rpm command.#*list servicesList the steps to determine detailed information regarding an install package via rpm and yum commands.#*stop List the steps to remove a servicepackage via rpm command.#*start List the steps to install a servicepackage using the yum command.#*Why is it important List the steps to learn how to manage services?remove a package using the yum command.#*Why is it important to stop certain services?