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[[Category:OPS235]]
{{Admon/caution|THIS IS AN OLD VERSION OF THE LAB|'''This is an archived version. Do not use this in your OPS235 course.'''}}
= LAB PREPARATION =
'''In this lab, you will create three virtual machines'''. This also gives you an opportunity to experiment with different ways of installing CentOS.
<br><br>
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|width="10%" | [[Image:harddrive.png|thumb|left|85px|<b>Removable Hard Disk Pack</b> (SATA)]]
# Open a web-browser, and open the OPS235 Lab #2 WIKI.
# Open a shell terminal.<br><br>'''WARNING:''' You must perform a '''yum update''' on your '''c7host''' machine before proceeding with the next steps.<br><br># You will need to download an image file for the Centos7 LIVE DVD by issuing the following command (best works while at Seneca):<br><b><code><span style="color:#3366CC;font-size:1.2em;">wget http://belmont.senecac.on.ca/centos/7/isos/x86_64/CentOS-7-x86_64-LiveGNOME-15031511.iso</span></code></b><br><br># Install the virtualization software by issuing the command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">yum install qemu-kvm qemu-img virt-manager libvirt libvirt-python \<br>python-virtinst libvirt-client virt-install virt-viewerbridge-utils</span></code></b> <br><br> {{Admon/important|Restart your Host Machine|You must restart your '''c7host''' machine after installing the virtualization program above. If you fail to do this, you may experience virtualization network problems!}}
::This will install many applications (including):
<ol>
<li value="5">Start the virtualization service: <b><code><span style="color:#3366CC;font-size:1.2em;">service libvirtd start</span></code></b></li>
<li>The firewall configuration is altered by the addition of the virtualization software. Restart Centos7 uses firewalld for firewall, but we will be switching back to using iptables. Issue the following series of command to install iptables and restart the firewall so that these changes become active: <br><br> <b><code><span style="color:#3366CC;font-size:1.2em;">systemctl stop firewalld</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">systemctl mask firewalld</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">yum install iptables-services</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">systemctl enable iptables</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">systemctl start iptables</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">service iptables restartsave</span></code></b><br><br></li>
</ol>
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== Part 1: Installing from a Downloaded Image (Centos7 LIVE CD) ==
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|{{Admon/tip|Perform Downloads and Network installs at Seneca|'''It is recommended to perform this lab in one of Seneca College's labs'''. This lab uses servers which are on the Seneca network and which are not available from other locations (such as your home). If you attempt this lab from another location, adjust the belmont.senecac.on.ca URLs to point to another mirror server -- note that you may need to change the directory name as well as the server name. The installation of the '''centos3''' virtual machine <u>must</u> be done at Seneca.}}
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{{Admon/important|Removing and Recreating VMs|If for some reason the user wants to remove a Virtual Machine, they can right-click the VM, and select delete in the Virtual Machine Manager. It is recommended to '''"delete the image file" in the remove VM dialog box when removing and then recreating a VM'''. Note: If you fail to properly remove the VM image file, it may affect the hard disk size for the new VM (i.e. use the old smaller size. Make certain to remove that VM image file prior to recreating the VM.|'''}}
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{{Admon/important|Restart your Host Machine Again|You must restart your '''c7host''' machine again, prior to creating your virtual machines. If you fail to do this, you may experience virtualization network problems!}}
:'''VM Details:'''
:: '''VM Name(and hostname):''' centos1
:: '''Boot media:''' LIVE CD Image
:: '''Installation source:''' Downloaded Centos7 LIVE CD image (http://belmont.senecac.on.ca/centos/7/isos/x86_64/CentOS-7-x86_64-LiveGNOME-15031511.iso):: '''VM Image Pathname:''' /var/lib/libvirt/images/centos1.img
:: '''Memory:''' 2GB
:: '''Disk space:''' 10GB
:: '''File System (root partition):''' ext4
:: '''CPUs:''' 1
# In the Virtual Machine Manger, click on the icon to ''Create a Virtual Machine'' in the upper-left corner:
# A window will appear with the title ''New VM''. There are five steps to be completed; click Forward after each step:
# '''Step 1 of 5:'''Select '''Local install media''' and click '''Forward'''.
# '''Step 2 of 5:''' Select '''Use ISO Image''', click the '''Browse''' button, and then the '''Browse Local''' button. Navigate to the location of the downloaded Centos7 LIVE CD image, select the image file and click '''Open'''. When finished, click Forward to proceed. If an error message appears regarding search permissions, just click '''yes''' to proceed.
# '''Step 3 of 5:''' Set the memory to '''2048 MB''' and the number of CPUs to '''1'''
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<ol>
<li value="1513">Enable SSH access to your virtual machine with these commands (semi-colon allows commands to be run in sequence):<br /> <b><code><span style="color:#3366CC;font-size:1.2em;">service sshd start; chkconfig sshd on</span></code></b></li> <li>Find out the IP address of your virtual machineand the name of your Ethernet network adaptor: <b><code><span style="color:#3366CC;font-size:1.2em;">ifconfig eth0</span></code></b> </li> <li>Enter the following command on your virtual machine to create a firewall exception to allow ssh traffic into the machine:<br /> <b><code><span style="color:#3366CC;font-size:1.2em;">iptables -I INPUT -p tcp -s0/0 -d0/0 --dport 22 -j ACCEPT</span></code></b></li> <li>If you are logged in as root, logout to your regular user account.</li><li>Confirm that you can ssh to your virtual machine from the host (your main CentOS installation): <b><code><span style="color:#3366CC;font-size:1.2em;">ssh c7host_IPaddressregularuserid@IPaddress</span></code></b> (where c7host_IPaddress '''regularuserid''' is your regular user login id, and '''IPaddress''' is the dotted-quad address '''IP_ADDRESS''' of your c7host machine'''centos1''' VM!).</li><li>Make certain to '''disable SELinux for centos1''' (refer to lab1)</li><li>Adjust your screen-saver settings and run a '''yum update''' on your centos1 VM before proceeding to ''Part 2''</li></ol>
'''Answer the Investigation 1 observations / questions in your lab log book.'''
== Part 2: Installing from the a Network =={| width="40%" align="right" cellpadding="10"|- valign="top"|colspan="2"|{{Admon/important|Authenticate to the network|The rest of this lab uses network access.''' Be sure to authenticate to the network using your browser before proceeding'''.}}|}
:'''VM Details:'''
:: '''VM Name(and hostname):''' centos2
:: '''Boot media:''' Network installation
:: '''Installation sourceURL:''' http://belmont.senecac.on.ca/centos/7/os/x86_64/:: '''VM Image Pathname:''' /var/lib/libvirt/images/centos2.img:: '''Memory:''' 1024MB2048MB
:: '''Disk space:''' 20GB
:: '''CPUs:''' 1
'''Answer the Investigation 2 observations / questions in your lab log book.'''
== Part 3: Installing from the a Network using a Kickstart File ==
:'''VM Details:'''
:: '''VM Name(and hostname):''' centos3
:: '''Boot media:''' Network installation
:: '''Installation sourceURL:''' http://belmont.senecac.on.ca/centos/7/os/x86_64/:: '''Kickstart locationFile URL:''' http://matrix.senecac.on.ca/~andrew.smith/ops235/centos7-kickstart-v01.cfg:: '''VM Image Pathname:''' /var/lib/libvirt/images/centos3.img:: '''Memory:''' 1024MB2048MB
:: '''Disk space:''' 15GB
:: '''CPUs:''' 1
# Create the VM as you did with the ''centos2'' virtual machine, specifying a network install as before, but specify the kickstart location under the "options section" for network install. What do you think is the purpose of this kickstart file?
# Observe the installation. How is it different from booting from an optical disca downloaded image?# Complete the installation. Record the time taken to install, and compare this to the time taken by the previous installations.<br><br>If the during the installation, you see the message at the bottom '''Pane is Dead''', click the '''Virtual Machine''' menu at the top, select '''Shut Down''' -> '''Force Off''', '''right-click''' on '''centos3''' in the ''virtual manager'' window and select '''Delete'''. Redo the VM setup for a new instance of the ''centos3'' VM.
# What happens when the installation is finished?
# Take a look at the kickstart file (eg. view url in a webj-browser) to determine the root password as well as the name and password for the first user account.!
# Boot the virtual machine and log in (use the user ID and password information from the previous step). Compare the experience to the first time you booted the other virtual machines. Record this information in the '''table contained in Investigation 4'''.
# Repeat the steps as you did to '''Answer start the Investigation 1 observations / questions in your lab log book.SSH service''', '''set iptables to accept connections via ssh''', '''test connections between centos3 and c7host''', and '''disable SELinux'''(refer to lab1). == Part 4: Updating the VMs == {| width="40%" align="right" cellpadding="10"|# Remember that centos3 is text- valign="top"|colspan="2"|{{Admon/caution|Never Shutdown Computer During Upgrade|Your computer based interface only (hostno graphics). To recover from a blank screen, vmspress a key (like the SPACE key) are at their most vulnerable when you perform an update. Always plan ahead for appropriate time prior to performing an updatereturn to the screen display. Shutting down your computer while performing an update may cause your computer not to boot! You have been warned!!!}}|}# In each VMRecord the time taken to install, run and compare this command: <b><code><span style="color:#3366CC;font-size:1to the time taken by the previous installations.2em;">yum update</span></code></b># Record your findings in the answers to these questions Installation Comparison chart in your log book:#* How long did it take to run on each VM? How many packages were updated?#* Why does it take longer in some VMs than others?lab2 logbook.
=INVESTIGATION 2: MANAGING VIRTUAL MACHINES=
|colspan="2"|{{Admon/note|Manage virtual machines from the host|The commands used to manage virtual machines must be executed on the host (your disk pack) and not inside a virtual machine.}}
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# Start the '''centos1''' virtual machine, and stop the '''centos2''' and '''centos3''' virtual machines.# Switch to the '''c7host ''' machine, and open a shell terminal.# Enter these admin commands into your '''c7host ''' machine and note the result:
:: <b><code><span style="color:#3366CC;font-size:1.2em;">virsh list</span></code></b>
:: <b><code><span style="color:#3366CC;font-size:1.2em;">virsh list --all</span></code></b>
|colspan="2"|{{Admon/note|Virtual Machine Does not Shutdown from Command|If the Virtual machine fails to shutdown from the <code>virsh shutdown</code> command, then you can go to the '''Virtual Machine manager''' and '''halt''' or '''shutdown''' within the VM itself, then you can click the '''PowerOff''' button in the VM window. You'll want to avoid a forced shutdown since those are equivalent to yanking the power cord out of the wall on a physical machine!|}}
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<ol><li value="4">Now, shut-down your centos1 VM normally, and close the centos1 VM window.</li><li>Switch to your terminal and issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">virsh start centos1</span></code></b></li><li>Using the appropriate command check to see if your centos1 VM is now running.</li><li>There are other commands that can be used (such as '''suspend''', or '''shutdown'''). The "shutdown" command may not always work since it relies on the guest handling a particular ACPI event. Why do you think it is useful to have commands to manipulate VMs?</li><li>Since this is a text-based version of Linux, you do not need to turn off the screen-saver.</li></ol>
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# Shut down all of the virtual machines.
# Change to the directory <b><code>/var/lib/libvirt/images/</code></b>. Note the size of the files in this directory. What do these files contain?# Make a compressed backup of the <code>'''centos3.img</code> ''' file to your home directory with this command: <b><code><span style="color:#3366CC;font-size:1.2em;">gzip < centos3.img > ~YourUserId/centos3.img.backup.gz</span></code></b><br />(Note: Make certain to use the redirection signs "<" and ">" properly in the command!)# Compare the size of the compressed and original files(hint: use '''ls -lh''').If file is very large (like 15GB), you didn't compress it and you need to remove that file and perform the previous step until you get it right!
# Start the '''''centos3''''' VM.
# '''Make certain that you are in your VM and <u>not</u> in your main system!'''
# >Wreck <u>only</u> your centos3 system! Try this command inside the centos3 virtual machine:<b><code><span style="color:#3366CC;font-size:1.2em;">rm -rf /*</span></code></b>(ignore error messages).# Shut down the centos3 VM. If you tried to start the centos3 VM, it would not boot since all system files have been removed!</li>
# Restore the original image from the backup in your home directory by typing this command: <b><code><span style="color:#3366CC;font-size:1.2em;">gunzip < ~YourUserId/centos3.img.backup.gz > centos3.img'''</span></code></b>
# Restart the VM. Is it working normally?
# Create compressed backups of your other virtual machines(ie. '''centos1''' and '''centos2''').</li>
# You should make a copy of the xml configuration file in case you "wipe" and re-install the host machine, and want to add a restored VM backups to the virtual machine manager list. We will demonstrate using the centos3 xml configuration file, and prove that a "clone" can be added to your list.Please perform the following step:
# Execute the following command: <b><code><span style="color:#3366CC;font-size:1.2em;">virsh dumpxml centos3 >centos3.xml</span></code></b># Examine the file <b><code><span style="color:#3366CC;font-size:1.2em;">centos3.xml</span></code></b>. What does it contain? What format is it in?<br><br># Make We will now learn how to download a compressed image file and xml configuration file and add it as a copy of VM to the virtual manager menu.# Issue the following commands:<ul><li><b><code><span style="color:#3366CC;font-size:1.2em;">centos3wget http://cs.xmlsenecac.on.ca/~murray.saul/ops235/practical1.img.gz</span></code></b> called <code/li>centos3a.xml</codeli>.# Edit the file <b><code><span style="color:#3366CC;font-size:1.2em;">centos3awget https://scs.senecac.on.ca/~murray.saul/ops235/practical1.xml</span></code></b>, making the following changes:<br><br></li></ul>::* Change the name (in <ol><li value="17">Copy these files to the file, not the file name) to '''centos3a/var/lib/libvirt/images'''::* Change at least one of directory and decompress the hexadecimal characters in the UUID. Do not change the length of the UUID. Valid hexadecimal characters are 0-9 and a-f.::image</li><li>Make certain your present working directory is:'''/var/lib/libvirt/images'''</li><li>Issue this the command: <b><code><span style="color:#3366CC;font-size:1.2em;">virsh define centos3apractical1.xml</span></code></b>:::Issue the command <b/li><codeli><span style="colorWhat happened in the virtual manager window? To remove a VM entry in the Virtual Manager window, simply issue the command:#3366CC;font-size:1'''virsh undefine vm_name''' (without the '''.2em;">virsh list --allxml''' file extension)</spanli></codeli>Launch the VM to see if it boots-up</bli> and record any changes.:::Issue the command: <bli><code><span style="color:Can you log into this VM? Perhaps your instructor will give you a clue in week #3366CC;font-size:17...2em >;"p<br>virsh undefine centos3a</spanbr></codeli></bol>
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<ol>
<li value="1722">List all of the virtual machines again, and note any changes. </li> <li>For the remainder of these labs, it is assumed that you will backup <u>'''both'''</u> the images and xml configuration files for <u>'''all'''</u> Virtual machines, when asked to backup your virtual machines. It is also highly recommended to backup these files to an external storage device (eg. USB key) in case the host machine gets "wiped" and you need to rebuild your HOST machine and then restore your Virtual Machines...</li>
<li>Answer this question in your log book:</li>
</ol>
::* In order to fully back up a virtual machine, what information should be saved in addition to the virtual machine image?
<ol><li value="24">A previous OPS235 student graciously created a shell script that you can download and run to check to see how you performed this lab (to see if you are on the right track).<br>Simply issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">wget http://matrix.senecac.on.ca/~murray.saul/ops235/lab2check2.bash</span></code></b> and run on your '''c7host machine'''.<br><br>'''If the shell script indicates any major errors, please inform your OPS235 instructor or lab assistant to advise what to do'''.<br><br></li></ol>
'''Answer the Investigation observations / questions in your lab log book.'''
<code style="color:#3366CC;font-family:courier;font-size:.9em;margin-left:20px;">
<br>
#!/bin/bash # Forces script to run in the bash shell
# backupVM.bash<br># Purpose: Creates system info report<br>#<br># USAGE: ./report.bash<br>#<br># Author: *** INSERT YOUR NAME ***<br>
# Date: *** CURRENT DATE ***
if [ $HOME PWD != "/root" ] # only runs if logged in as root's directory<br>then<br> echo "You must be logged located in as /root." >&2<br> exit 1<br>fi
</code>
<br>
if [ "$answer" = "y" ] # Backup all VMs if answer is yes<br>
then<br>
for num in 1 2 3 # Determinant loop for 3 arguments: 1, 2, and 3<br>
do<br>
echo "Backing up VM #$num"<br>
gzip < /var/lib/libvirt/images/centos$num.img > /root/centos$num.img.backup.gz<br>
<br> echo "VM #$num BACKUP DONE"<br>
done<br><br>
elif [ "$answer" = "n" ]<br>
read -p "Which VM should be backed up? (1/2/3): " numanswer<br>
until echo $numanswer | grep "^[123]$" >> /dev/null # Look for match of single digit: 1,2, or 3<br>
<ol>
<li value="7">Save, set permissions, and then run that shell script to backup centos1. Confirm that this script did backup this image to root's home directory</li><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/vm-start-text.bash<br>https://scs.senecac.on.ca/~murray.saul/vm-stop-text.bash</span></code></b><br><b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">https://scs.senecac.on.ca/~murray.saul/vm-start.bash<br>https://scs.senecac.on.ca/~murray.saul/vm-stop.bash</span></code></b></blockquote></li><li>Try to understand what these Bash Shell scripts do.</li><li>#You have completed lab2. Proceed to Completing The Lab, and follow the instructions for "lab sign-off".</li></ol>
'''Answer all observations / questions in your lab log book.'''
= LAB 2 SIGN-OFF (SHOW INSTRUCTOR) =
= Preparing for = Practice For Quizzes , Tests, Midterm & Final Exam ==
# What is the name of the CentOS installation program?