== USEFUL INFORMATION FOR INSTRUCTORS (ALL SEMESTERS - PLEASE READ!)== #In the '''lab 1 instructions for SSD''', students are instructed to download the image to their windows machine (i.e. Downloads), then create a '''VM template, then edit it with instructions:'''<br><br><span style="background-color:yellow;">In this setup dialog box, click the options tab and then click the Advanced option at the bottom of the list. On the right-hand side, click the checkbox to enable the option to Boot with EFI instead of BIOS.<br>Then click on the Hardware tab, and then select the CD/DVD (IDE) device and select in the right-side select the radio button for the use ISO Image file. Click the Browse button and specify the path of your downloaded Centos7 Full install DVD (most likely file is contained in your Downloads folder). Click Processors, and click the check-box to enable Virtual Intel VT-X/EPT or AMD-V/RVI. When finished, click on the OK button. </span><br><br>Many students have done this for more than 3-4 semesters with their SSDs. Generally no problems encountered. '''Occasionally, students do not follow instructions and forget to set virtualisation for host VM with would affect nested VMs using KVM in lab2...'''. Examples: Can't edit Grub boot file, VMs cannot be installed properly in KVM, Installed VMs in KVM cannot be started, etc.<br><br>The instructions are there. '''I usually do install with students for lab1 Investigation 1 with students (only time I do lab with students) to help them get on the right track'''.<br><br># Subject: RE: '''How to allow students to obtain free VMware Workstation 12 Pro for use at home''' (eg. SSDs)<br><br>'''*** REQUIRED FOR INSTRUCTORS TO DO THEMSELVES - NO ONE WILL DO THIS FOR YOU ***'''<br><br>Students are entitled to free licensed version of VMware Workstation 12 Pro.<br>It is available for ALL OPS235 / OPS335 students, but particularly useful for students that have SSD drive and want to work from home of notebook computer. You, as an instructor NEED to send Clive (e-mail:<br>clive.beetge@senecacollege.ca) with just usernames (can be done via Blackboard or moodle) students. I recommend you also post an announcement for your student like this:<br><br><blockquote>''"All OPS235/OPS335 students in my course is allowed a free version of VMware Workstation 12 Pro for their personal use. This particularly useful for students that have Solid State Drives and want to work on OPS235 labs at homeusing VMware Workstation 12 Pro. I have e-mailed the administrator your seneca userid, and you should be getting an email with a long subject line.<br><br>WARNING: Check your quarantine and spam filters to see if this email gets trapped since spam filters may automatically trap suspicious emails with long subject lines.<br><br>Open that e-mail to obtain your VMware Workstation 12 Pro software and registration key.<br><br>FYI<br>Insructor's Name"''</blockquote><br><br>'''NOTE:''' If students cannot access this information from their email, and if Clive has created their accounts, they can use the link and following instructions to obtain their program:<br>https://e5.onthehub.com/WebStore/Welcome.aspx?ws=d529a1f1-b430-e511-940e-b8ca3a5db7a1&vsro=8<br><br># It is possible to run VMware VMs from the command line using the following steps <syntaxhighlight lang="bash">Create a directory for links to your VMware VMs# mkdir ~/links# cd links # ln -s /path/to/VMs/file.vmx Use vmrun to start/stop/list/getGuestIPAddress/listProcessesInGuest# vmrun | less# vmrun -T ws start ~/links/name-of-CentOS-VM-link.vmx [gui|nogui]# vmrun list# vmrun -T ws getGuestIPAddress ~/links/name-of-CentOS-VM-link.vmx# ssh user@address-got-from-line-above# vmrun -T ws -gu <guest-user> -gp <guest-password> listProcessesInGuest ~/links/name-of-CentOS-VM-link.vmx</syntaxhighlight>In case you get an error message about Guest Additions not being installed, you have to rerun <code>vmrun installTools ~/links/name-of-CentOS-VM-link</code> and, during the Guest Additions installation, choose yes to automatic kernel modules (default during installation is no), see: [ [https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2050592 Known issue about Guest Additions not being loaded despite being installed] ] and [ [https://www.vmware.com/pdf/vix162_vmrun_command.pdf (PDF) manual for vmrun ] ] for additional information.# When updating packages if you abort suddenly, then you might end up with a broken package database. ## In that case, you can fix a broken yum package system using the following blog post: [ [https://wphosting.tv/how-to-fix-duplicate-packages-in-yum/ How to fix duplicate packages in yum] ].<br>Good to know and include somewhere (OPS235 future content update).## This might another set of steps to follow:<syntaxhighlight lang="bash"># yum-complete-transaction# yum check | tee /tmp/yum-check.log # yum update --skip-broken# package-cleanup --problems# package-cleanup --dupes# package-cleanup --cleandupes# yum install initial-setup initial-setup-gui gnome-initial-setup# yum update# reboot</syntaxhighlight><br /><br /># VMware on Linux requires Secure Boot to be disabled on the Linux host otherwise VMware cannot run CentOS VMs: [ [https://communities.vmware.com/message/2461448#2461448 Comment #5 talks about disabling Secure Boot to make VMware on Linux boot VMs] ]. =Current : Summer 2018 Semester=# '''A quick note about replacing firewalld with iptables: ''I've found that disabling firewalld isn't always enough.'' ''' Certain processes and packages can re-enable firewalld automatically and without notice. When this happens, though firewalld and iptables are both set to start with the system, firewalld takes precedence. Iptables will never start up. This can cause problems for students, as firewalld can interfere with some of our labs and they assume firewalld is disabled at this point. I recommend we amend Lab 1 to instruct students to fully remove firewalld from their systems. I also recommend checking status of firewalld be part of your troubleshooting toolbox when helping students with strange issues. --Chris Johnson = Winter 2018 Semester =# It appears that doing yum update after May 2018 reintroduces the GRUB issue mentioned in '''#3''' of '''Fall 2017''' below for removable HDD on HP machines. A possible solution, since the one proposed in the earlier solution does not work, might be (to be confirmed whether the solution linked to here resolves the issue) https://noobient.com/post/165797742756/fixing-the-efi-bootloader-on-centos-7 = Fall 2017 Semester= # '''Network glitch corrected by Mehrdad where network install (URL copy from Belmont) hung up install due to missing software repository'''.<br>'''Cause''': due to firewall protocol system implementation in Spring/Summer, it blocked the "yum" protocol, and now has been <u>'''fixed'''</u> system-wide.<br><br>'''FYI:''' '''Murray Saul''' verified that the fix worked by successfully created a VM via network install.<br><br># <span style="color:red;">'''ATTENTION:'''</span> Mehrdad mentioned that possibly in the next semester (or eventually), the belmont server URLs will be removed. The alternative (and eventual replacement) that affects OPS235/OPS335 is: mirror.senecacollege.ca/centos/7/os/x86_64/<br>Therefore, this corrections should be made for OPS235 and OPS335 labs for the Winter 2018 startup prior to classes.<br><br># <span style="color:red;">'''ATTENTION:'''</span> Verify your CentOS release version using '''rpm -qa centos-release'''. If it is '''1708''' <u>and</u> you are using a '''removable hard drive''' with boot issues then do the following: copy '''grubx64.efi''' from [http://mirror.centos.org/centos/7/os/x86_64/EFI/BOOT/ CentOS EFI/BOOT site here] into your /boot/efi/EFI/BOOT directory of your hard drive. To get to that directory of your hard drive you would need to boot from a live CentOS USB or CD/DVD and mount the /boot partition of your HDD. Try to do this yourself, otherwise ask for help from the lab tutor or instructor. You would also need to refresh your grub configuration using help from [https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html-single/System_Administrators_Guide/index.html RedHat], [https://wiki.centos.org/HowTos/Grub2 CentOS] and [http://www.gnu.org/software/grub/manual/grub.html Grub] or use the following [[File:grub.cfg]] for help. This directory tree is known to work<br><br><syntaxhighlight lang="bash">/boot/efi/EFI/├── BOOT│ ├── BOOTX64.EFI│ ├── fbx64.efi│ ├── grub.cfg <=== NEW: MUST BE PRESENT (create using grub2-mkconfig -o filename)│ └── grubx64.efi <=== NEW: MUST BE PRESENT (get using link CentOS EFI/BOOT in text above)└── centos ├── BOOT.CSV ├── BOOTX64.CSV ├── fonts │ └── unicode.pf2 ├── grub.cfg ├── grubenv ├── grubx64.efi ├── mmx64.efi ├── shim.efi ├── shimx64-centos.efi └── shimx64.efi</syntaxhighlight><br><br># In Lab2 (both versions), change from downloading raw image file (.img) to qcow2 file, and call it sample_test_image to get student to launch and login a sample version for exposure for future practical tests.<br><br># For next semester add in procedure for SSDs to create a duplicate image file for c7host in case the original is corrupted. Should also include warning about properly unmounting SSD device prior to removing from computer<br><br> = Winter / Summer 2017= # There seems to be a procedure that works if you are booting Centos7 from your removable SATA drive in your labs and it doesn't connect to the Internet...<br>Note: If you cannot connect, you should see on the top right-hand corner before you login such as: '''<span style="font-size:1.5em;font-family:monospace;">[...]</span>'''<br>This means there is no Internet connection.<br><br>If that is the case, perform the following steps:<br><ol type="a"><li> Quickly press the power button (do not hold it down!). This should put it in suspend mode. You can confirm it is in suspend mode if the blue power light is flashing.</li><li>Wait a few seconds, then press the power button again. This will go out of suspend mode. You can confirm is is not in suspend mode if blue power light is solid (not flashing).</li><li>In a few seconds, the symbol on the top right-hand side should appear like: <span style="border-color:black;border-width:2px;border-style:solid;"> &nbsp; &nbsp; </span>.<br>This symbol means that you can connect to the Internet.</li></ol><br><br># A problem with kernel panic discussed on this thread and is on going as of Jan 10, 2017 (solved but Mark F. is facing difficulties after performing an aborted upgrade on my centos1-like VM which I was using for teaching ULI101. This solution doesn't help Mark but the advice given on this thread might be relevant to some). Here is link: [ [https://www.centos.org/forums/viewtopic.php?f=47&t=51911&start=10 Kernel panic at restart after so update] ]<br /><br /># We keep (but rename to something more appropriate) the existing HDD option in OPS235 labs because some students are requesting to install CentOS on their laptop (dual boot or single boot) and so continue doing the lab with all 3VMs on the laptop itself. So no VMs inside a VM stuff for them, except maybe name the labs from external HDD to 'using your own laptop' or some such.<br /><br /># In case a yum update goes wrong and the advice given by the next run of yum update does not work in making the VM boot into GNOME, then try the following: '''yum install initial-setup initial-setup-gui gnome-initial-setup'''. You might have to reboot and agree to the license conditions at firstboot. <br /><br /># Nested virtualization is incredibly slow if the host VM (VMware c7host) is using the default number of processor cores (1). Since all processing is done under c7host, it is safe to share all of your cores with Windows and VMware (c7host).<br /><br /> =Fall 2016=

== Lab 5 == #Suggestion suggestion (received from a student:) ==

Create a virtual disk /dev/vda in centos2 in Lab 5 and use that virtual disk (vda) instead of /dev/sda (so use '''fdisk /dev/vda ''' instead of using '''fdisk /dev/sda'''). This makes Lab 5 easier to handle accidental corruption students might make while doing that lab thereby destroying their centos2. This might require Lab 5 checker script to be tweaked to work with /dev/sdavda.