Changes

=LAB PREPARATION=Purpose / Objectives of Lab 4=={| width="40%" align="right" cellpadding="10"|- valign="top"|[[Image:users.png|thumb|right|150px|System administrators are required to add, remove and modify user accounts.]]|[[Image:on-off.png|thumb|right|135px|In order to perform maintenance, system administrators need to know how to stop and start services for a Linux system. ]]|}

<u>Main objectivesObjectives</u>:

:* Add a virtual hard disk and expand your vmAdminister '''s existing file system using LVM:* Administer (add, remove, modify) users ''' on a Linux system.:* Save time while adding new users using a template of '''start-up files'''.:* Create and manage '''groups ''' on a Linux system.:* '''Start and Stop services ''' on a Linux system.:* Display the '''status of running services ''' on a Linux system.  

{|cellpadding="15" width= Required Materials (Bring to All Labs) =="40%"

|width==Prerequisites=="10%" | [[Image:harddrive.png|thumb|left|85px|<b>Removable Hard Disk Pack</b> (SATA)]]

* Completion and Instructor |width="Sign-off10%" of Lab 2: |[[OPS235 Lab 3 Image:ubs- CentOS6key.png|thumb|left|85px|<b>USB key</b><br>(for backups)]]

|width==Linux Command Online Reference==Each Link below displays online manpages for each command (via "10%" |[[httpImage://linuxmanpageslog-book.compng|thumb|left|70px|<b>Lab4 Log Book</ http://linuxmanpages.comb>]]):

|} ==My Toolkit (CLI Reference)== {|width="10050%" cellpadding="515"|'''LVM Information Utilities:'''|'''LVM Management Utilities:'''|'''Additional Utilities:'''

|width="10%" |<u>User Management:</u>*[http://linuxmanpagesunixhelp.comed.ac.uk/man8CGI/vgs.man-cgi?useradd+8.php vgsuseradd]<br>*[http://linuxmanpagesunixhelp.comed.ac.uk/man8CGI/lvs.man-cgi?userdel+8.php lvsuserdel]<br>*[http://linuxmanpagesunixhelp.ed.comac.uk/man8CGI/pvs.man-cgi?usermod+8.php pvsusermod]<br>*[http://linuxmanpagesunixhelp.ed.comac.uk/man8CGI/vgdisplay.man-cgi?groupadd+8.php vgdisplaygroupadd]<br>*[http://linuxmanpagesunixhelp.com/man8/lvdisplayed.8ac.php lvdisplay]*[http:uk/CGI/linuxmanpages.com/man8/pvdisplay.man-cgi?groupdel+8.php pvdisplaygroupdel]|width="10%" |<u>Managing Services</u>*[http://wwwunixhelp.ed.centosac.org/docs/5uk/htmlCGI/Deployment_Guideman-en-US/s1-system-config-lvm.html system-config-lvmcgi?chkconfig+8 chkconfig] (Tutorial)<br>*[http://linuxmanpagesunixhelp.ed.comac.uk/man8CGI/lvextend.man-cgi?service+8.php lvextendservice]<br>*[http://linuxmanpageswww.dsm.fordham.comedu/man8cgi-bin/resize2fs.8man-cgi.php resize2fspl?topic=systemctl systemctl]<br>|width="10%" |<u>Miscellaneous</u>*[http://linuxmanpagesman7.comorg/man8linux/lvcreate.8.php lvcreate]*[http:man-pages/man5/linuxmanpagespasswd.5.comhtml /man8etc/lvreduce.8.php lvreducepasswd]<br>*[http://linuxmanpagesman7.comorg/man8linux/pvcreate.8.php pvcreate]*[http:man-pages/man5/linuxmanpagesgroup.5.comhtml /man8etc/vgextend.8.php vgextendgroup]<br>|*[http://linuxmanpagesman7.comorg/man8linux/mount.8.php mount]*[http:man-pages/man5/linuxmanpagesshadow.5.comhtml /man8etc/umount.8.php umountshadow]<br>*[http://linuxmanpagesarchive.com/man8/useraddlinuxfromscratch.8.php useradd]*[http:org/blfs-museum/linuxmanpages1.com0/man8/userdel.8BLFS-1.php userdel]*[http:0/postlfs/linuxmanpagesskel.comhtml /man8etc/usermod.8.php usermodskel]<br>*[http://linuxmanpages.com/man8/groupaddzenit.8senecac.php groupadd]*[http://linuxmanpageson.comca/man8wiki/groupdel.8index.php groupdel/Init_vs_systemd init vs systemd]

# Look at the <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/passwd </span></code></b> file.

# Read about the file: http://man7.org/linux.die.net/man-pages/5man5/passwd .5.html

#Perform this part in your '''centos1''' VM.# Read the man page for the <b><code><span style="color:#3366CC;font-size:1.2em;">useradd </span></code></b> command.# Create a new user account for each of your pod mates, using three fictitious users (make-up their learn account name as a user nameuserids and full names. Give each user of these newly-created users a password.# Grep the <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/passwd </span></code></b> file for each of the new users.#* What is the '''home ''' directory of each user?#* What '''group ''' is each user in?#* What else do other information can you know about each userprovide regarding these users?#* Where are the '''passwords ''' stored?# Look at the man page for '''/etc/shadow ''' using the command : <b><code><span style="color:#3366CC;font-size:1.2em;">man 5 shadow</span></code></b>#* Grep the <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/shadow </span></code></b> file for each of the new users.

# Create two new dummy users, <b><code><span style="color:#3366CC;font-size:1.2em;">ops235_1 </span></code></b> and <b><code><span style="color:#3366CC;font-size:1.2em;">ops235_2</span></code></b>.

#* How does the operating system determine which files are created in a new home account? The answer can be found here: <br>http://www.linuxhowtos.org/Tips%20and%20Tricks/using_skel.htm

#* Create a new file in this directory with the following command: <b><code><span style="color:#3366CC;font-size:1.2em;">touch foo</span></code></b>#* Create a new user named <b><code><span style="color:#3366CC;font-size:1.2em;">foobar</span></code></b>, with the option to automatically create a home directory.

{{Admon/note|Use centos3|Perform these steps in the '''centos3''' virtual machineAnswer the Part 2 observations / questions in your lab log book.}}# Add your matrix account user to '''centos3'''.

{{Admon/note|Use centos1|Perform these steps #Remain in the your '''centos1''' virtual machineVM for this section.}} # Read the man page for the <b><code><span style="color:#3366CC;font-size:1.2em;">groupadd </span></code></b> and <b><code><span style="color:#3366CC;font-size:1.2em;">groupdel </span></code></b> commands.# Note which option allows you to set the Group ID number ('''GID''') when you create a new group.# Examine the file <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/group</span></code></b>

#* Add a new group named <b><code><span style="color:#3366CC;font-size:1.2em;">ops235 </span></code></b> with a GID of <b><code><span style="color:#3366CC;font-size:1.2em;">600</span></code></b>.#* You are angry The management at your organization have concerns regarding some irresponsible users on your system.#** Add a new group named idiots'''investigation'''.#** Look at '''/etc/group ''' and note the GID of idiotsgroup called '''investigation'''.#** What GID is given to a new group if if you do not specify it?#** Your anger In the file, add those users to the end of the concerned group (separate each user-name with a comma).#** Those individuals have explained their actions to management and the crisis has subsidedbeen resolved. Delete the idiots '''investigation''' group.#** Look at '''/etc/group ''' again and note the change.

Be sure to record your '''Answer the Part 3 observations / questions in your lab noteslog book.'''

== Part 4: Deleting users / Modifying Users ==

{{Admon#Remain in your '''centos1''' VM for this section.# Read the man page for the '''userdel''' command. Note which option automatically removes the users home directory when that user is deleted.# Delete the user '''ops235_1''' using the command <b><code><span style="color:#3366CC;font-size:1.2em;">userdel ops235_1</note|span></code></b># Delete the user '''ops235'''_2 using the same command with the option which removes the home directory of the user.# Check the contents of the /home directory. What do you notice?# Check the contents of the <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/group</span></code></b> file. What do you notice?# Read the man page for the usermod command. Note which options change the user's full name, primary group, supplementary groups, and shell.# Create a new user account called '''noobie''' for the employee: '''"Really Green"''' . Assign a password for that newly created user.# Management has indicated that this employee be on on probation for 3 months. Use the '''usermod''' command to set the account for noobie to expire in 3 months from this day as part of the security policy of this organization.# Add each of your new users to the group ops235 (in other words, add ops235 to each user as a supplementary group).# Examine <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/group</span></code></b>. What has changed?# Use centos1|Perform these steps the '''usermod''' command to change the full name of the user account '''noobie''' from '''"Really Green"''' to '''"Outstanding Employee"'''. Examine the result of running that command in the <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/passwd</span></code></b> file. What has changed?# Use the '''usermod'centos1'' command to extend the use of their account for 5 years as of today.# Be sure to record your observations in your lab notes. ''' virtual machineAnswer the Part 4 observations / questions in your lab log book.}}'''

# Delete =INVESTIGATION 2: Managing System Services and Run-levels= Many students may think that the user ops235_1 using the command <code>userdel ops235_1</code>following topic is small and "not a big deal". Those students may say, '''"How hard is running and stopping services?"''' # Delete The process may not be hard, but knowing how to stop, start, restart and check the user ops235_2 using status of services is absolutely critical to a Linux server. '''Aside from learning to trouble-shoot problems''' by checking the same command with the option which removes the home directory status of the userrunning services, '''understanding how to manage services is critical to help protect a Linux server from penetration''' (this term is referred to as "'''Hardening a system'''"). Sometimes it is "what we don't know" that can harm us.# Check the contents One key element in hardening a computer system is to disable non essential networkng services to allow IDSs ('''Intrusion Detection Systems''') to focus on a narrower range of the /home directorypolicy violations. A Debian-based penetration testing distribution called '''Kali''' (formerly referred to as '''"BackTrax"''') allows sysadmins and security professionals to identify vulnerabilities in their computer systems, and thus improve (harden) their systems against penetration. What do you notice?# Check Learning to monitor the contents of status, enable and disable networking services underlies the /etc/group file'''Backtrax''' motto:<br><br>'''''"The quieter you are, then more you will hear. What do you notice?.."'''''<br><br>

{{Admon#Use your '''centos2''' VM for this part.<ol> <li value="2">Use the '''man''' pages to learn about the '''service''' command.</note|li><li>Issue the following Linux command: <ul> <li><b><code><span style="color:#3366CC;font-size:1.2em;">service --status-all</span></code></b></li> </ul> </li> <li>Note the services that are currently running.</li> <li>Use centos1|Perform these steps the command <b><code><span style="color:#3366CC;font-size:1.2em;">service iptables stop</span></code></b> to stop the service named '''iptables'''</li> <li>Run a command to verify that the '''iptables''' service has stopped.<br><br>'''NOTE:''' Although the service command seems to work, it is <u>'''deprecated'''</u> (i.e. "out-dated:). It has been replaced by using the [http://zenit.senecac.on.ca/wiki/index.php/Init_vs_systemd#systemd_Command_Usage systemctl] command. This is a command based upon a newer method of starting and managing system services called [http://zenit.senecac.on.ca/wiki/index.php/Init_vs_systemd systemd] (which replaces init - the "initialization table"). This method allows services to run more independently of each other, so that a service may be stopped without other dependent services to be stopped as well.<br><br>The most common '''systemctl''' commands are shown below (it is optional to include the filename extension '''.service''' after the service-name):<ul><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl list-units --all'''</span> &nbsp; (get a listing of all service names. Can pipe to grep to list service you are interested in )</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl status service-name'''</span> &nbsp; (Confirm status of a service - running or not-running)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl stop service-name'''</span> &nbsp; (stop a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl start service-name'''</span> &nbsp; (start a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl restart service-name'''</span> &nbsp; (restart a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl enable service-name'''</span> &nbsp; (enable service so service runs upon system startup)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl disable service-name'''</span> &nbsp; (disable service so it does NOT run upon system startup)<br><br></li></ul></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.<br>To turn it off permanently we need to use the '''systemctl''' command:<b><code><span style="color:#3366CC;font-size:1.2em;">systemctl disable iptables</span></code></b><br>(the '''chkconfig''' command used to be the way to enble/disable services, but is now deprecated).</li> <li>Use the '''systemctl''' command to verify that the '''centos1iptables''' service is no longer running ('''hint:''' issue command, and pipe to grep "'''iptables''' virtual machine").}} <li>Reboot and confirm that it's no longer running.</li></ol>

# Read the man page for the usermod command'''Answer Part 1 observations / questions in your lab log book. Note which options change the user's full name, primary group, supplementary groups, and shell.''

# Add each of your new users to the group ops235 (in other words, add ops235 to each user as a supplementary group).# Examine <code>/etc/group</code>. What has changed===Part 2: How do we Manage Runlevels?# Use the usermod command to associate each of your pod mates' full name to their user name. With each change, examine their entries in the <code>/etc/passwd</code> file. What has changed?# Be sure to record your observations in your lab notes.===

=INVESTIGATION 2: Managing RunRunning servers in graphical mode will make your system most likely to be penetrated. The X-Levels and System Services=windows framework can be vulnerable to attacks when these servers are connected to the Internet. This is why when you install server versions of Linux, they work in text-based mode only. Desktop versions of Linux are then installed on workstations (working in graphical mode) that connect to the server (for security reasons).

<livalue="2">Issue the following Linux command:

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

<li>Note the difference in output between '''centos2 ''' and '''centos3'''.</li> <li>You can use the <code>'''init</code> ''' command to change the current runlevelrun-level. See a list of runlevels [https://www.centos.org/docs/5/html/5.2/Installation_Guide/s2-init-boot-shutdown-rl.html here]. Use the <code/li>man</codeli> Use the '''man''' command to learn how to use the <code></code>'''init ''' command. Use this command to change the current runlevel run-level in '''centos2 ''' to '''3'''. What happened? What happens after your reboot?</li> <li>Change the default runlevel on centos2 to 3. What happens now after you reboot?</li> <li>Issue the following Linux command:

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

<li>Using systemd requires a different method of setting text mode and graphical mode. You can refer to this link for future reference: [http://fedoraproject.org/wiki/Systemd#How_do_I_change_the_runlevel.3F How to Change the default runlevel for Run-Levels with Systemd]</li><li>Restart your centos2 back to 5 machine, and reboot make certain that it runs in '''graphical''' mode</li> </li>Why would you want to make sure it works.a graphical Linux system run in text-based mode?</li>

=== '''Answer Part 2: How do we Manage System Services? ===observations / questions in your lab log book.'''

We have seen = INVESTIGATION 3: LOOKING AHEAD = ==Automating Routine Tasks (Shell Scripting)=={|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/tip|Bash Shell Scripting Tips:|<br><ul><li>'''The case statement:'''<br><br>The case statement is a control-flow statement that works in a similar way as the if-elif-else statement (but is more concise). This statement presents scenerios or "cases" based on values or regular expressions (not ranges of values like if-elif-else statements). After action(s) are taken for a particular scenerio (or "case"), a break statement (''';;''') is used to "break-out" of the statement (and not perform other actions). A default case (*) is also used to catch exceptions.<br><br><u>'''Examples (try in shell script):'''</u><br><br>''read -p "pick a door (1 or 2): " pick<br>case $pick in<br>&nbsp; 1) echo "You win a car!" ;;<br>&nbsp; 2) echo "You win a bag of dirt!" ;;<br>&nbsp; *) echo "Not a valid entry"<br>&nbsp;&nbsp;&nbsp;&nbsp; exit 1 ;;<br>esac''<br><br>''read -p "enter a single digit: " digit<br>case $digit in<br>&nbsp; [0-9]) echo "Your single digit is: $digit" ;;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; *)&nbsp;echo "not a valid single digit"<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exit 1 ;;<br>esac''<br><br></li><li>'''The getopts function:'''<br><br></li></ul>The getopts function allows the shell scripter to create scripts that accept options (like options for Linux commands). This provides the Linux administrator with scripts that maintaining unneeded provide more flexibility and versatility. A built-in function called '''getopts''packages can be ' (i.e. get command options) is used in conjunction with a '''while''' loop and a security risk''' due case''' statement to carry out actions based on if certain options are present when the unnecessary increase shell script is run. The variable '''$OPTARG''' can be used if an option accepts text (denoted in the complexity getopts function with an option letter followed by a colon. Case statement exceptions use the ''':)''' and '''\?)''' cases for error handling.<br><br>'''<u>Example of getopts</u>''' (try in script and run with options)<br><br>''while getopts abc: name<br>do<br>&nbsp; case $name in<br>&nbsp; &nbsp; a) echo "Action for option \"a\"" ;;<br>&nbsp; &nbsp; b) echo "Action for option \"b\"" ;;<br>&nbsp; &nbsp; c) echo "Action for option \"c\""<br>&nbsp; &nbsp; &nbsp; &nbsp; echo Value is: $OPTARG" ;;<br>&nbsp; &nbsp; :) echo "Error: You need text after -c option"<br>&nbsp; &nbsp; &nbsp; &nbsp; exit 1 ;;<br>&nbsp; &nbsp; \?) echo "Error: Incorrect option"<br>&nbsp; &nbsp; &nbsp; &nbsp; exit 1 ;;<br>esac''<br>done<br><br>}}|} We will now use shell scripting to help automate the task for a Linux adminstrator to create regular user accounts.  #You will be using your system'''c7host''' machine for this section. Similarly#Download, it is also unnecessarily hazardousstudy, and run the following shell script. Issue the command:<br><b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">wget https://scs.senecac.on.ca/~murray.saul/user-create.bash</span></code></b>#Try to understand what these Bash Shell scripts do, and even more sothen run the script as root. After running the shell script, view the contents of the '''/home''' directory to confirm.  Although the '''zenity''' command is a "user-friendly" way to leave unneeded services runningrun shell scripts, Linux administrators usually create shell scripts that resemble common Linux commands. In this investigationlab, we you will learn how to create a shell script using the getopts function to make your shell script behave more like actual Linux commands (including the use of options). Refer to the notes section on the right-hand-side for reference about the '''case''' statement and the '''getopts'''control servicesfunction.  <ol><li value="3">Open a Bash shell terminal and login as root.</li><li>Use the wget command to download the input file called user-data.txt by issuing the command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">wget https://scs.senecac.on.ca/~murray.saul/user-data.txt</span></code></b></li><li>View the contents on the user-data.txt file to confirm there are 3 fields (username, fullname, and turn off those services that we think e-mail address)which are separated by the colon (:) symbol.<li><li>Use a text editor (such as <b><code><span style="color:#3366CC;font-size:1.2em;">vi</span></code></b> or <b><code><span style="color:#3366CC;font-size:1.2em;">nano</span></code></b>) to create a Bash Shell script called: <b><code><span style="color:#3366CC;font-size:1.2em;">createUsers.bash</span></code></b> in /root's home directory.</li><li>Enter the following text content into your text-editing session:</li></ol><code style="color:#3366CC;font-family:courier;font-size:.9em;margin-left:20px;"><br>&#35;!/bin/bash <br><br>&#35; createUsers.bash<br>&#35; Purpose: Generates a batch of user accounts (user data stored in a text file)<br>&#35;<br>&#35; USAGE: /root/createUsers.bash [-i {input-path}] <br>&#35;<br>&#35; Author: *** INSERT YOUR NAME ***<br>&#35; Date: *** CURRENT DATE ***<br><br>if [ $PWD != "/root" ] # only runs if in root's home directory<br>then<br>&nbsp;echo "You must be in root's home directory." >&2<br>&nbsp;exit 1<br>fi<br>if [ "$#" -eq 0 ] # if no arguments after command<br>then<br>&nbsp;echo "You must enter an argument" >&2<br>&nbsp;echo "USAGE: $0 [-i {input-path}]" >&2<br>&nbsp;exit 2<br>fi<br></code><br><ol><li value="6">Save your editing session, but remain in the text editor.</li><li>The code displayed below uses the getopt function set the input file pathname or check for invalid options or missing option text. Add the following code</li></ol><br><code style="color:#3366CC;font-family:courier;font-size:.9em;"><br>outputFlag="n"<br>while getopts i: name<br>do<br>&nbsp;case $name in<br>&nbsp; &nbsp;i) inputFile=$OPTARG ;;<br>&nbsp; &nbsp;:) echo "Error: You need text after options requiring text"<br>&nbsp; &nbsp; &nbsp; &nbsp;exit 1 ;;<br>&nbsp; &nbsp;\?) echo "Error: Incorrect option"<br>&nbsp; &nbsp; &nbsp; &nbsp; exit 1 ;;<br>&nbsp;esac<br>done<br></code><ol><li value="6">Save your editing session, but remain in the text editor.</li><li>The code displayed below uses logic to exit the script if the input file does not necessary exist. Command substitution is used to help reduce security risksstore each line of the input file as a positional parameter. There is one subtle problem here: The full names of the users contain spaces which can create havoc when trying to set each line as a separate positional parameter. In this case the sed command is used to convert spaces to plus signs (+), which will be converted back later. Finally, a '''for''' loop is used to create each account ('''useradd''') and mail the user their account information ('''mail'''). Add the following code:</li></ol><br><code style="color:#3366CC;font-family:courier;font-size:.9em;"><br>if [ ! -f $inputFile ]<br>then<br>&nbsp; echo "The file pathname \"$inputFile\" is empty or does not exist" >&2<br>&nbsp; exit 2<br>fi<br><br>set $(sed 's/ /+/g'$inputFile) # temporarily convert spaces to + for storing lines as positional parameters<br><br>for x<br>do<br>&nbsp; &nbsp; userPassWd=$(date | md5sum | cut -d" " -f1)<br>&nbsp; &nbsp; useradd -m -c "$(echo $x | cut -d":" -f2 | sed 's/+/ /g')" -p $userPassWd $(echo $x | cut -d":" -f1)<br>&nbsp; &nbsp; mail -s "Server Account Information" $(echo $x | cut -d":" -f3) <<+<br>&nbsp; &nbsp; Here is your server account information:<br>&nbsp; &nbsp; servername: myserver.}}senecac.on.ca<br>&nbsp; &nbsp; username: $(echo $x | cut -d":" -f1)<br>&nbsp; &nbsp; password: $userPassWd<br>&nbsp; &nbsp; Regards,<br>&nbsp; &nbsp; IT Department<br>+<br>done<br><br>echo -e "\n\nAccounts have been created\n\n"<br>exit 0<br></code>

<livalue="8">Issue the following Linux command: <ul> <li><code>service --status-all</code></li> </ul> </li> <li>Note the services Save, set permissions, and then run that are currently running.</li> <li>Use the <code>service</code> command to stop shell script for the service named input text file '''iptablesuser-data.txt'''</li> <li>Issue . Did it work? Try running the <code>service</code> command to verify that this service has stopped.script without an argument - What did it do? </li> <li>If you reboot now - the iptables service will be turned back onYou have completed lab4. We don't want it on thoughProceed to Completing The Lab, it causes students headaches. To turn it off permanently we need to use and follow the chkconfig command: <code>chkconfig iptables instructions for "lab sign-off</code></li> <li>Reboot and confirm that it's no longer running".</li></ol>

'''Answer the Investigation 5 3 observations / questions in your lab log book.'''

{{Admon/important|Time for a new backup!|If you have successfully completed this lab, make a new backup of your virtual machinesas well as your host machine. Remember to also make a backup |}} '''Arrange proof of the new second virtual disk drive following on the screen:''' <ol><li><span style="color:green;font-size:1.5em;">&#x2713;</span> '''centos1''' VM:<blockquote><ul><li>Account created on '''centos1'' ' VM</li><li> List contents of '''/etc/group''' file (ops235 group)</li><li>List contents of '''/etc/passwd''' file (created accounts)</li></ul></blockquote><li><span style="color:green;font-size:1.5em;">&#x2713;</span> '''centos2''' VM:<blockquote><ul><li>Display current run- you now have two virtual disks level status on ''centos1'centos2''' VM</li></ul></blockquote></li></li><li><span style="color:green;font-size:1.5em;">&#x2713;</span>'''c7host''' machine<blockquote><ul><li>Creation of your bash shell script called '''createUsers.bash'''</li></ul></blockquote></li><li><span style="color:green;font-size:1.5em;">&#x2713;</span> '''Lab4''', and therefore two image files, and therefore will need two backup fileslog-book filled out.}}</li></ol>

= Preparing for the = Practice For Quizzes , Tests, Midterm &amp; Final Exam ==

# Describe all of the field in <code>'''/etc/passwd'''</code># What is the command to create a VGuser? PV? LVWhat option to create a home directory for that user? # What is the total size command to change the full name of the "main" VG on your systeman already-created user?# How do you create What is the command to delete a LVuser account?# How do you delete an LVWhat option allows for the user's home directory to be removed as well?# How would you add What is the disk partition <code>/dev/sdb7</code> command to your volume create a group "main"?# How would you increase What is the size of the root filesystem by 50 MBcommand (or steps) to include a user in a newly-created group?# What is the purpose of <code>'''/etc/fstabshadow'''</code>?# What is the purpose of <code>'''/etc/shadowskel'''</code>?# What does the term run-level mean?# How to set the run-level of a Linux system to text-based only? How to set to graphical mode?# What is the command to view the status of running services?# What is the command to start a service (like httpd, or sshd)?# What is the command to start a service?# Can a service be stopped and started by issuing just one command?