Changes

:* '''Correctly install the CentOS 7 FULL INSTALL DVD''' (not LIVE DVD) on your removable hard disk. * '''Record installation characteristics of CentOS 7 FULL INSTALL''' in a chart (contained in lab2 logbook chart) to compare with other installation methods performed in lab2. * '''Verify correct settings''' prior to proceeding with host installation stages.

:* '''Verify correct settingsObtain Linux server information after installation''' prior to proceeding with host installation stagescreate a software asset report for later access.

:* '''Obtain Disable Linux server information after installationKernel security enhancements''' to create allow easier internal networking connections (to be reactivated in a software asset report for later accesslab).

:* Observe that '''Disable Linux Kernel security enhancementsBash Shell Scripts can automate routine tasks''' to allow easier internal networking connections (to be reactivated in a later lab).

==Minimum Required Materials / Lab Preparation=={|cellpadding="15" width="100%"

| [[Image:blank-cd.png|thumb|left|100px75px|<b>CentOS 7</b>FULL INSTALL DVD]]

| [[Image:harddrive.png|thumb|left|100px75px|<b>Removable Hard Disk Pack</b> (SATA)]]

|[[Image:ubs-key.png|thumb|left|100px75px|<b>USB key</b><br>(for backups)]]

|[[Image:log-book.png|thumb|left|75px60px|<b>Lab Log Book</b><br>(labs 1 & 2)]]

|width="40%" |{{Admon/tip|Access to Instructions for Lab1|Since you will performing a full install on your computer, you cannot use that computer to simultaneously view instructions while you perform the full install. Here are some suggestions to make this process easier:<ul> <li>'''Printout Lab1 instructions''' at home prior to performing Lab1</li> <li>'''Use a smart-phone, notebook, or netbook computer to view lab instructions''' (highly recommended)</li><li>If lab space availability is not an issue, '''use another computer termimal to view lab instructions''' while performing install</li><li>'''Follow step-by-step instructions from your OPS235 instructor''' (if demonstrated by instructor)</li></ul>|

==My Toolkit (CLI Reference)== {|width="100%" cellpadding|- valign="5" width="50%top"

|<u>Networking</u> 

|<u>Miscellaneous</u> [http://unixhelp.ed.ac.uk/CGI/man-cgi?grep grep]<br>

{{Admon/important |You're supposed For the next 3 investigations, you will learn how to use this install your Centos Full DVD onto your removable hard drive only for this course| But if you really need disk. You will customize your install to use it for two courses, and the professor for the other setup several separate partitions:<ul><li>'''/''' (The "root" partition)</li><li>'''/home''' (Store regular user accounts)</li><li>'''/var/lib/libvirt/images''' (probably windowsstore virtual machine images to be created in lab2) </li><li>'''swap''' course will allow it - ask partition (Virtual Memory)</li></ul> Make certain to record your professor observations of this install in the comparison chart for help with partitioning'''c7host''' in your lab2 logbook.}}

   ::'''<u>Host Machine Details:</u>''' ::*'''Name:''' c7host::*'''Boot media / Installation:''' CentOS7 Full Install DVD::*'''Memory:''' 16GB::*'''Disk space:''' 250GB (or higher)::*'''CPUs:''' 1 {| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{Admon/important |You're supposed to use this hard drive only for this course| But if you really need to use it for two courses, and the professor for the other (probably windows) course will allow it - ask your professor for help with partitioning.}}|- valign="top"|[[Image:lab2-logbook.png|thumb|right|100px|'''comparison chart''' in lab2 logbook.]]|[[Image:installation_summary.png|thumb|right|500px400px|The <b>'''Installation Summary ''' screen</b> provides flexibly when configuring to install on your computer. ]]|} # Refer to this listing of installation screenshots if you need a reference:<br>[ [http://matrix.senecac.on.ca/~murray.saul/ops235/installation/ installation screenshots] ]<br>

# Restart '''Newer computer models''' are labelled '''HP Z230'''.<br><br>'''NOTES:'''<ul><li>If you are using the '''<u>newer</u>''' model, allow the computerto boot up (<u>without</u> pressing F10 key) to boot from DVD.</li><li>Refer to the comparison chart in lab2 lab logbook, and fill in various installation information for '''c7host''press ' while you perform the function key F10installation (such as time it took to perform a full install, installation options, press ENTERetc).<br><br></li></ul><ol> <li value="6">Power on the computer again, and specify after booting from the CD, select from the device to installation menu: '''Install Centos7'''.<br><br>Note: If you experience unreadable display after you bootinto your installed system, you can redo the install, but select from the install menu: ''<u>Troubleshooting</u>'' and then select ''<u>Install in Basic Graphics Mode</u>'' (eg. DVD drive)<br><br></li> <li>Next, you will be prompted for a language. In the first screen, select language '''English''' with subselection '''English-Canada''' and then click the '''Continue''' button on the bottom right-hand screen.</li>

:: <li>The '''NOTE:Install Summary''' Refer should now appear. This screen allows the installer to customize their Centos7 system prior to installation.</li> <li>Configure the comparison chart in lab2 lab logbook, and fill in various following installation information for settings from the ''Install Summary Screen'c7host''' while :<br><br><b>DATE & TIME:</b><ul><li>Click on the Map to select Toronto area (you perform may also select from the drop-down menu section)</li><li>Click the <b>DONE</b> button at the top-left corner to finish and return to the Installation Summary screen.</li></ul><br><b>NETWORK & HOSTNAME:</b><ul><li>Select the default Ethernet connection and click the button on the top right-hand side to change the setting from <b>OFF</b> to <b>ON</b>.</li><li>At the bottom left-hand corner type the installation hostname: <b>c7host</b> (such as time all lowercase letters)</li><li>Review your settings, then click the <b>DONE</b> button at the top-left corner to finish and return to the Installation Summary screen.</li></ul><br><b>SOFTWARE SELECTION:</b><ul><li>Select the software packages labelled: <b>Gnome Desktop</b></li><li>Click the <b>DONE</b> button at the top-left corner to finish and return to the Installation Summary screen.</li></ul><br></li> <li>Although the Centos installtion program can provide suggestions on how to partition your hard disk, you will be customizing partitions for your hard disk. This custom partitioning is important since it took to will have consequences on future labs that you perform a full install, installation options, etc(especially for lab2).<br><br>Proceed to '''Part 2''' to customize your partitions.</li></ol>

{|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/tip|Mount Points and Linux File System Types|Similar to other Operating Systems like windows '''fat''' / '''vfat''' / '''ntfs''' file system types, it is good to know a few common file system types in Linux for comparison:<br><ul><li><b>xfs:</b> &nbsp; Newer filesystem (fast transfer rates for large files, Journaling)</li><li><b>ext4:</b> &nbsp; Newer filesystem supporting large files and Journaling (used in for this lab)</li><li><b>ext2:</b> &nbsp; Stable filesystem popular for databases (no journaling)</li></ul>|}}|-|[[Image:partition_verification.png|thumb|right|500px550px|Take time Carefully verify partition mount-names and sizes prior to confirm that your partitions are correct before proceeding with install. Check [http://matrix.senecac.on.ca/~murray.saul/ops235/installation/ installation screenshots] link for verification. ]]<ol>|} <li>If you get a warning with something like "This device may contain data" - it#From the installation summary screen, click '''Installation Destination'''s probably your new hard drive and you can safely use it.</li> <li>Select #In the installation destination screen, select the destination option: '''I will configure partitioning'''and then click 'Create Custom Layout''Done'', we don't want to use the default setup now. #The manual partitioning screen should appear.#If you are using a have used your hard drive that contains partitions from a disk for previous course Linux (previous version of LinuxCentos)distributions, delete all partitions prior to proceedingyou should remove them. Click on the distribution, and for each partition, select the partition and click the remove button (minus sign) and confirm deletion.</li> #<lispan style="background-color:yellow">On your drive you Change the option '''New mount points will need use the following partitions. These may be primary partitions or logical drives.<br>Remember that the sizes are recorded in MB (eg. 20 GB = 20000 MB) and you should multiply GB by a factor of 1024 partition scheme''' from '''LVM''' to get the correct size (eg. '''20 GB x 1024 = 20480 MB<u>Standard Partition</u>'''(you will not be using LVM for your c7host machine)<br/span> If .#Before you have more space than 250GB available - you can add proceed with creating partitions, let's see the extra space in equal parts partitions that we need to /home and /var/lib/libvirt/images</li> create for our host computer:<ul><li>Primary Partitions (ext4): <ul> <li>'''20GB30GB''' for '''/''' (i.e. "root")</li> <li>'''30GB40GB''' for /home</li> <li>'''100GB''' for '''/var/lib/libvirt/images''' </li> </ul> </li> <li>Swap Partition: <ul> <li>'''8GB16GB''' (Note: "swap" must be selected from the drop down menu)</li> </ul></li> </ul><br>'''NOTE:''' Remember that the sizes are recorded in MB (eg. 30 GB = 30000 MB) and you should multiply GB by a factor of 1024 to get the correct size.<br> (eg. '''30 GB x 1024 = 30720 MB''')<br><br>#We will now create the root (/li) partition. '''Click on the add button (plus) sign'''.<br> #In the '''Add a New Mount Point''' screen, select '''/''' as the mount-point (either by typing or selecting from drop-down menu), and enter '''30720''' in for partition size and click '''Add Mount Point''' button. # You will return to the previous dialog box.<br><lispan style="background-color:yellow">For the '''/''' partition, change the file-system type from '''xfs'''Take time to carefully verify '''ext4''' and make certain that the Device Type is set to Standard Partition (<u>not</u> LVM). You need to repeat this procedure for the ''/home'' and ''/var/lib/libvirt/images partitions'' as well)</span>.#Repeat the same steps above for the '''/home''' partition informationand '''/var/lib/libvirt/images''' partition. For example, if You need to type the pathname ''/var/lib/libvirt/images '' partition since it does not appear in the drop-down menu.#Recheck each of the created partitions, and make certain that the file-system type is set to ''ext4'' and the Device Type is misspelledset to ''Standard Partition''.#Finally, add a swap partition (Mount Point: swap) for '''16 GB'''.#Check that your partition settings are correct (you would need can ask your instructor or lab monitor to redo lab1!.confirm), and then click '''Done''' (possibly '''<u>twice</liu>''') in order to proceed<br><br> <lispan style="background-color:yellow">Record briefly in '''NOTE:''' If there is an error message associated with your lab logbook what created partitions , you created of what size and what device names were assigned may need to them (add a '''/devboot/sda1efi''' partition (as a new mount). The capacity should be: 2954MB (i.e. 2, etc954 MB).)Once finished, click '''Done'''.</lispan><br> <libr>After confirming partition settings, #A Summary of Changes screen will appear to show the partitioning operations that will be created. Click the '''Accept Changes''' and click next and select '''write changes to diskBegin Installation'''in the Installation Summary screen to proceed with the installation. The #Start timing your host machine installation program will create and format the partitions.</li> </ol>

== Part 3: Complete Completing the Installation ==[[Image:install_completed.png|thumb|right|500px|This screen indicates that installation is complete. You should remove the install DVD and confirm Centos7 boots from your removable hard drive. ]]<ol> <li>Accept the default settings to create the Bootloader and click next.</li> <li>Make certain that '''Desktop''' applications have been selected, and accept the default settings in the '''additional repositories''' section (at the bottom), then proceed. You may look at what's available if you choose "Customize now" but you don't need to customize the software installed at this point.</li> <li>Add in your lab logbook a brief description of the term "software repository" and what its major purpose serves (what you think it does). We will not add any existing repositories since we are not currently connected to the Internet. Therefore, we will customize the repositories later.</li> <li>'''Proceed with the installation. This may take some time'''. Record in your lab log-book the <u>general</u> steps in the installation process (displayed in the dialog box).</li> <li>When installation is complete, a screen will confirm completion, and will then ask the user to remove the DVD, and reboot the computer. Write in your lab log-book the time it took to perform this DVD install.</li> <li>Remove the Installation DVD, and click '''Reboot'''.</li>

<li>Remember to press F10 when restarting {|width="40%" align="right" cellpadding="10"|- valign="top"|[[Image:completed.png|thumb|right|500px|This screen indicates that installation is complete. You should remove the computer, install DVD and select the your SATA drive to boot confirm Centos7 boots from your removable hard drive.</li>]]|} <li>When #During the system startsinstallation process, a one-time setup program you will run required to add create a '''root password''' (for administration access) and create a '''regular user accounts, account'''. Click on '''Root Password''' and enter your root password. Think of an appropriate password and record that password somewhere in case you forget! An indicator will appear to set date show you how secure your password is. Retype your root password and time.click '''Done''' (you may have to click Done <u>twice</liu>if your password is not considered to be a strong password). <li>Create #You need to create a regular user account for yourself using the same . This account will be used to graphical log into your host machine. It is never recommended to graphically log into a graphical Linux/Unix system as root. It is better to log into a regular user ID account, then run a command to login as root (you will learn how to do this later in this lab).#Click '''User Creation''' and enter your learn account'''full name''', '''username''', and create an appropriate '''password''' (and confirm password). Click '''Done''' to finish (click twice if password is not considered to be a suitable strong password).#<span style="background-color:yellow">Remember to record this host installation information in the '''installation comparison chart''' in the lab2 logbook</lispan>. #When installation is complete, you will notice a message at the bottom of the screen stating: '''CentOS is now successfully installed and ready for you to use!'''#Click the Reboot button. Your DVD will <liu>briefly</u>Set or open in the DVD drive bay. Make certain to remove this installation DVD so that Centos will boot from your hard drive.#After the system reboots, a boot menu should briefly appear, then prompt the user to accept the License Information (this is only a one-time and date defaultoccurrence). Normally<br> In order to accept the license agreement, you would want to enable issue the following keystrokes:<br><br>'''Network Time Protocol1''', but since we will be experimenting with followed by ENTER (to select the networking turned off in later labs, license agreement prompt<br>'''leave it disabled2'''.followed by ENTER (to accept the license agreement)</libr> '''c''' followed by ENTER (to save the selection)<libr>Accept all other defaults '''c''' followed by ENTER (you can ignore a second time to continue booting into the Kdump featuresystem)<br><br>#The system should then graphically prompt the user to login with their regular user account. Finish Click on your '''regular user account name''' and '''enter your regular user password'''.<br><br>#The last phase of the post-installation customization process should now run:<ul><li>Confirm English as the default input source and then login to your computer account that you createdclick '''Next'''.</li> <li>Proceed to Investigation 2Skip the creation of online accounts by clicking '''Next'''.<li>Start using your installed Linux system by clicking '''Start Using CentOS Linux'''.</li></ul><br> #Stop timing your installation and note the amount of time that your installation took to perform. Also take the time to fill in the c7host section of the installation comparison chart in your lab2 logbook.#Open a web-browser and check to see if you can connect to the Internet.</olbr><br>

=INVESTIGATION 2: OBTAINING HOST MACHINE SYSTEM INFORMATION=Your system automatically enables a '''screen-saver''' application which is a useful security tool to prevent unauthorized viewing of information on a terminal after a certain amount of inactivity.

After switching user notice and make note of the change in your shell prompt. Also note the difference in output for the <codeol>whoami</codeli value="14"> andProceed to Investigation 2 to obtain basic information from your newly installed Centos Host machine.<code/li>pwd</codeol> commands.

'''Whenever this is required, make a note of it, Answer Investigation 1 observations (all parts and determine why superuser privilege is requiredquestions) in your lab log book.'''

In some documentation, you may see the command <code>su -</code> used in place of <code>su</code>. The dash argument causes <code>su</code> to go through the steps that would normally be performed when the root user logs in, including (1) running the startup scripts (such as<code>/etc/profile</code> and <code>/root/.bash_profile</code> and (=INVESTIGATION 2) changing to the root user's home directory (<code>/root</code>).: OBTAINING HOST MACHINE SYSTEM INFORMATION=

# The With older (ancient) versions of Linux, a user once may have been allowed to login to their graphical Linux system using '''root''' as their user-name of and their root password. This has been determined to be a security risk and that option has been removed with many or all Linux operating systems.#Therefore, from this point onwards, you will be logging into your regular user account instead and issuing a command to login as the ''root'' user. #Refer to the Information box regarding how to access the admin account from the command line.#Issue the installation log file is command <b><code><span style="color:#3366CC;font-size:1.3em;">su </span></code></b> Issue the '''pwd''' and '''whoami''' commands to confirm your directory pathname. When finished logout of this account.#Issue the command <b><code><span style="color:#3366CC;font-size:1.3em;">su - </span></rootcode></installb> Issue the '''pwd''' and '''whoami''' commands to confirm your directory pathname.logWhat do you notice are the main differences between using '''su''' versus using '''su -'''?# An installation log file called <b><code><span style="color:#3366CC;font-size:1.2em;">/var/log/anaconda/packaging.log</span></code> -- It </b> has been created to record the installation of your c7host machine. This file is an ASCII file (how can you be sure?) which can be viewed with the <b><code>'''less'''<span style="color:#3366CC;font-size:1.2em;">more</span></code></b> command.

:: <codeb>'''grep ________________ ________________ | wc -l'''</code><ol> <li valuespan style="3color:#3366CC;font-size:1.2em;">Using the <code>rpm<grep -i packaging /code> command: you can also use the following commands to list all the installed packages, and the total number of packages installed:<var/li><log/ol>:: <code>'''rpm -q -a'''<anaconda/code>:: <code>'''rpm -q -a packaging.log | wc -l'''</codespan>:: </code>'''rpm -qa | wc -l'''</codeb>

<li value="48">The <code>'''-q'''</code> option means queryIssue that command displayed above. Does it work? If not, and the <code>'''-a'''</code> option means all (what account do you think you should be in other words, query all installed software packages). Did ? When you get the same number of packages from command working record this important information regarding commands and the above two methods?admin account in your lab logbook.</li> <li>Some of the files on your system were installed with the software packages, and some were created by system activity (for example, by creating your Learn account and by logging in). If you know the package name (from Using the <code>install.logrpm</code>), command: you can also use the following commands to list all the files that were installed from packages, and the package by using the following commandtotal number of packages installed:</li>

:: <b><code><span style="color:#3366CC;font-size:1.2em;">rpm -q -a'''</span></code></b>::<b><code><span style="color:#3366CC;font-size:1.2em;">rpm -q -a | wc -l package_name'''</span></code><br /b>::<b><code><span style="color:#3366CC;font-size:1.2em;">(where rpm -qa | wc -l'''package_name''' represents the name of the ''application'' or ''package'')</span></code></b>

<li value="610">This combines the The <code>'''-q'''</code> (option means query) option with , and the <code>'''-la'''</code> option means all (list filenamesin other words, query all installed software packages) option. Did you get the same number of packages from the above two methods?</li> <li>You can pipe Some of the files on your system were installed with the software packages, and some were created by system activity (for example, by creating your Learn account and by logging in). If you know the outupt through <code>'''wc -l'''</code> to count package name (from the number of lines:</li></ol>:: <code>'''rpm -ql package_name| wc -l'''packaging.log</code><ol> <li value="8">Using what ), you learned in steps 3, 4, and 7, get a count of can list all the total number of files that were installed from the package by all of using the software packages on your system.following command:</li>

<ol><li value="12">Issue the following command to obtain the total number of files installed for gedit:<br><br></li></ol>::<b><code><span style=Part2" pointer-events:none;cursor:default;color: Obtaining System and Network Information==#3366CC;font-size:1.2em;">rpm -ql gedit | wc -l</span></code></b>

<livalue="13">To find out the name that Using what you have assigned to your Linux systemlearned in steps 3, 4, enter the command: <code>'''hostname'''</code></li><li>To find out the kernel version of your GNU/Linux workstation and the date it was created7, enter get a count of the command: <code>'''uname -rv'''</code></li><li>To find out total number of files installed by all of the system processes running software packages on your GNU/Linux workstation, enter the command: <code>'''ps -ef'''</code>system.</li><li>To capture How can you explain why this number is a lot larger than the list total number of all the system processes to a file called <code>'''pspackages installed? Record your answer in your lab logbook.lst'''</code>, enter the command: <code>'''ps -ef > ps.lst'''''</code></li>

{|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/important|Pathname for USB Stick|The default mount location has been changed in linux distributions newer than CentOS. So while we will get '''/media/usb-device-name''', in newer distributions you'll see '''/run/media/userloginid/usb-device-name'''}}|}#To find out the name that you have assigned to your Linux system, enter the command: <b><code><span style="color:#3366CC;font-size:1.2em;">hostname</span></code></b>#To find out the kernel version of your GNU/Linux workstation and the date it was created, enter the command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">uname -rv</span></code><ol/b>#To find out all the system processes running on your GNU/Linux workstation, enter the command: <li valueb><code><span style="13color:#3366CC;font-size:1.2em;">Copy ps -ef</span></code></b>#We will now collect networking information for your installed system.#To check the network configuration settings obtained from the DHCP server, run the following commands, describing the installation output in your log file book:::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">ifconfig</span></code></b>::: <b><code>'''<span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">route -n</span></rootcode></installb>:::<b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.log'''2em;">nslookup</span></code> and </b> (at the file ''nslookup'ps.lst''' to a USB memory keyprompt, or enter the word '''scpserver''' and record the output. Type exit to your matrix account as a backupleave nslookup).<ol><li value="8">Find the following information in the output of the above commands:</li></ol>::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">MAC address<li/span></code></b>View of the section below to learn about and perform an update on your fresh CentOS install ethernet network interface:::<b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">Subnet mask</span></code></b>::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">The IP address </span></code></b> (you may have assigned to find spare time to perform this install if you are running short on lab timeby the DHCP server)::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1. '''Do 2em;">The default gateway<u/span>not</ucode></b>::: <b> proceed to Investigation 3 without performing an update'''<code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">The DNS nameserver</lispan></code></b><ol><livalue="9">Run the commands <b><code><span style="color:#3366CC;font-size:1.2em;">hostname</span></code></b>The CentOS software is updated frequently to add features, fix bugs<b><code><span style="color:#3366CC;font-size:1.2em;">uname -rv</span></code></b>, and upgrade security<b><code><span style="color:#3366CC;font-size:1. Perform a system update to get the latest versions of the packages installed2em;">ps -ef</span></code></b>, <b><code><span style="color:#3366CC;font-size: Start the Firefox web browser, turn off popup window blocking (select ''Edit1.2em;">ifconfig</span></code></b>Preferences'', then select the Content tab and uncheck <b><code><span style="color:#3366CC;font-size:1.2em;">route -n</span></code></b> redirecting the box output to Block Popups), then login add to SeneNET. Open a terminal and type file in root's home directory called <b><code>su<span style="color:#3366CC;font-size:1.2em;">system.txt</span></code> to start a shell as root</b>. Enter </li><li>Copy the command installation log file <code>yum update'''/var/log/anaconda/packaging.log'''</code> This will download and install all of the packages that have been updated since the installation DVD image was createdfile '''system. If you complete this command at Seneca it should run quite fast as Seneca College hosts txt''' to a CentOS Repository mirror (a copy of all of the current CentOS packagesUSB memory key, on or '''scp''' to your matrix account as a local web server)backup.</li></ol>

# Your system may not be automatically connected to Seneca's network. Locate the network icon (on top right-hand panel). Click on that icon, and select '''system eth0'''# Open a web-browser and log into Seneca's wired network. You will need to perform this set every time you start a new session with your computer to perform future labs.#Open a shell terminal.#To check the network configuration settings obtained from the DHCP server, run the following commands, describing the output in your log book==Part 1:#* '''ifconfig'''#* '''route -n'''#* '''nslookup''' (at the > prompt, enter the word "server" (do not type the quotes) Disable SELinux and record the output. Type exit to leave nslookup).# Find the following information in the output of the above commands:#* '''MAC address''' of the ethernet network interface#* '''Subnet mask'''#* '''The IP address''' assigned to you by the DHCP server#* '''The default gateway'''#* '''The DNS nameserver'''Perform Software Updates==

{|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/important|SELinux|SELinux stands for '''Security-Enhanced Linux'''Answer . It is a component that helps to better secure the system to protect against intrusion (hackers). SELinux is enabled upon the Investigation 3 observations default install of CentOS. SELinux can be a good thing, if you take care of it and know how it works. For this course it is strongly recommended that you '''disable SELinux by default''' because we won't have the time to reconfigure it every time the labs make it necessary.}}|}# Disabling SELinux is quite simple, just edit the file '''/ questions etc/selinux/config''' and set SELINUX to '''disable<u>d</u>'''.# Add additional text regarding disabling SELinux.#The CentOS software is updated frequently to add features, fix bugs, and upgrade security. Perform a system update to get the latest versions of the packages installed: Start the Firefox web browser, turn off popup window blocking (select '''Edit''', '''Preferences''', then select the '''Content''' tab and uncheck the box to '''Block Popups'''), then return to your web-browser, load a page, and when prompted, login to SeneNET. #Make certain that you have at least 30 minutes available in your lab log book-time prior to performing a system update. Never abort a system update since it may damage your system files and render your host mahcine inoperable!#Open a terminal and type <b><code><span style="color:#3366CC;font-size:1.2em;">su</span></code></b> to start a shell as root. Enter the command <b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">yum update</span></code></b> This will download and install all of the packages that have been updated since the installation DVD image was created. If you complete this command at Seneca it should run quite fast as Seneca College hosts a CentOS Repository mirror (a copy of all of the current CentOS packages, on a local web server).'''

==Part 12: Disable SELinuxAutomating Routine Tasks (Shell Scripting)==

{|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/importanttip|SELinuxBash Shell Scripting Tips:|SELinux stands for <br><ul><li>'''SecurityShe-Enhanced Linuxbang line: #!/bin/bash'''<br><br>Shell scripts have evolved of the past 40 years. It To avoid running a newer shell script on an older shell, it is a component that helps recommended to better secure force running the system shell script in the correct shell. In order to protect against intrusion do this, on the first line at the very beginning of the shell script, you add the '''#!''' (hackers'''# as in "shhhh" - a comment''', and''' ! is referred to as "bang" run a commmand''': in this case, '''run the command: /bin/bash'''). SELinux You can issue the Linux command '''which bash''' to get the correct location. If there is enabled upon no bash shell on that machine, the shell script will not run (as a precaution - the Linux admin will know how to make a fix to the default install shell script if required).<br> </li><li>'''Variables:'''<br><br> There are 3 types of variables that can be used in shell scripting: '''ENVIRONMENT''' (eg. $USER), '''user-defined''' ($varName), and '''positional parameters''' (eg. $1, $2... containing arguments after shell script or by using set command (eg. '''set $(ls)''' ). Using dollar sign ('''$''') in front of CentOSvariable expands the value assigned.<br><br></li><li>'''Command Substitution:'''<br><br>A very useful trick to take output from a command to be used as an argument for another command. SELinux Examples include:<br>'''file $(ls)'''<br>'''set $(ls);echo $#;echo $*'''<br>'''echo "hostname: $(hostname)"'''<br><br><li>'''Logic Control Flow Statements:'''<br><br>The '''test''' command can be used to see if a good thingcondition is true or false<br>(i.e. test $USER &#61; "root") . The '''$?''' special shell variable stores the result (zero if true, non-zero if false). Square brackets '''[ ]''' can be used to represent the test command with the condition <u>inside</u> the brackets (spaces separating brackets).Can use '''if you take care of it and know how it works''' / '''if-else''' / '''if-elif-else''' statements with brackets. The '''exit''' command can be used to terminate the shell script with a false value. <br><br>'''<u>Examples</u>'''<br><br>''if [ $USER &#61; "root" ]''<br>''then''<br>&nbsp;''echo "You must be root" >&amp;2''<br>&nbsp;''exit1''<br>''fi''<br><br># For this course it is strongly recommended that you number comparison: use:<br># -gt,-ge, -lt, -le, -eq, -ne<br><br>''if [ $age -gt 65 ]''<br>''then''<br>&nbsp;''echo "retire"''<br>''else'disable SELinux by default'<br>&nbsp;'' because we wonecho "don't retire"''<br>''fi''<br><br>''if [ $grade -gt 79 ]''<br>''then''<br>&nbsp;''echo "You get Good Mark"''<br>''elif [ $grade -gt 49 ]''<br>''then''<br>&nbsp;''echo "You pass"''<br>''else''<br>&nbsp;''echo "You fail"''<br>''fi''<br></li></ul>}}|}You may have the learned about creating and running Bash Shell Scripts in your ULI101 course. Shell scripts help Linux users and system administrators to automate repetitive tasks to become more efficient and to help them save time . You will be reviewing and building a basic Bash Shell script to reconfigure it every generate information reports for your newly-installed Linux host machine. Take time to view Shell Scripting Tips which are located on the labs make it necessaryright-hand side.}}

# Disabling SELinux is quite simpleIf you require <u>'''additional practice'''</u> in creating shell scripts and using the vi text editor, just edit run the file commands in your '''Matrix''' account: <ul><li>'''/etchome/selinuxmurray.saul/configvi-tutorial'''</li><li>'' and set SELINUX to disabled'/home/murray.saul/scripting-1'''</li></ul>

==Part 2Perform the following steps in your '''c7host''' machine: Automating Routine Tasks (Shell Scripting)==

= COMPLETING THE LAB / INSTRUCTOR SIGN-OFF =[[Image:lab1_signoff.png|thumb|right|500px|Students should be prepared with a'''ll required commands (system information) displayed Answer the Investigation 3 observations / questions in a terminal (or multiple terminals) prior to calling the instructor for signoff'''.]]'''Check off the following items before asking your instructor to check your lab:log book.'''

= LAB 1 SIGN-OFF (SHOW INSTRUCTOR) =[[Image:lab1_signoff.png|thumb|right|500px|Students should be prepared with '''all required commands (system information) displayed in a terminal (or multiple terminals) prior to calling the instructor for signoff'''.]]'''Arrange evidence (command output) for each of these items on your screen, then ask your instructor to review them and sign off on the lab's completion:'''

* Can login with your ::<span style="learncolor:green;font-size:1.5em;" account name>&#x2713;</span> Output of '''lsblk''' command showing correct partition names and sizes* Has the package count* Has correct ::<span style="color:green;font-size partitions for::* 1.5em;">&#x2713;</span> Contents of '''root /etc/fstab''' (20GB), file confirming partitions file types are '''ext4'''::<span style="color:green;font-size:1.5em;">&#x2713;</homespan> Correct ''' (30GB), IP address'''swapand ''' (8GB):* MAC address'''::<span style="color:green;font-size:1.5em;">&#x2713;</var/lib/libvirt/imagesspan> ''' Default route (100GBgateway)''':* Hint: Can issue <span style="color:green;font-size:1.5em;">&#x2713;</span> '''lsblkDNS name server IP Address''' or ::<span style="color:green;font-size:1.5em;">&#x2713;</span> Contents of your '''blkidmyreport.bash'''shell script* Has the correct IP address and MAC address* Find out the default route (gateway)* IP ::<span style="color:green;font-size:1.5em;">&#x2713;</span> proof of the DNS name server'''yum update''' performed on c7host* Name and contact information ::<span style="color:green;font-size:1.5em;">&#x2713;</span> '''SELinux''' is disabled on your disk pack'''c7host'''* Lag Logbook (::<span style="color:green;font-size:1.5em;">&#x2713;</span> '''lab1) notes filled-''' <u>and</u> '''first column of Comparison Chart inlab2'''.

= ADDITIONAL PRACTICE = Practice For Quizzes, Tests, Midterm &amp; Final Exam ==

# How many users were created automatically on your system (do not count your learn accountregular, admin)?# What is List 2 ways that you can access your learn root account's UID and GID?# What is your learn accountthe difference between the commands '''su''' and '''su -'''s home directory ?