== USEFUL INFORMATION FOR INSTRUCTORS (ALL SEMESTERS - PLEASE READ!)== # In the '''N.B. - On "TODO list"lab 1 instructions for SSD''' - , students are instructed to download the image to their windows machine (i.e. Downloads), then create a '''LAB 1 - Picture under part 2VM template, then edit it with instructions:''' <br><br><span style="background- The picture called color:yellow;"Partition Verification" shows a LVM >In this setupdialog box, but 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 ask specifically are there. '''I usually do install with students for a standard partition setuplab1 Investigation 1 with students (only time I do lab with students) to help them get on the right track'''.<br><br># Subject: RE: '''FIXED BUT REQUIRES VERIFICATION THAT FIX WORKEDHow 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 ***'''LAB 1 <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- Investigation 3 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- Part 2 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- Questions 21mail to obtain your VMware Workstation 12 Pro software and registration key.<br><br>FYI<br>Insructor's Name"'' - Not important but</blockquote><br><br>'''NOTE:''' If students cannot access this information from their email, and if Clive has created their accounts, report3they can use the link and following instructions to obtain their program:<br>https://e5.bash script uses 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="cat 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 ~/rootlinks/installname-of-CentOS-VM-link.log 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> installation_reportand, during the Guest Additions installation, choose yes to automatic kernel modules (default during installation is no), see: [ [https://kb.html"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 file 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 /roottmp/installyum-check.log does not exist on centos7 # 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 =#'''NA 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.BIptables will never start up. On List This can cause problems for Murray Saul 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 work on during nonfully remove firewalld from their systems. I also recommend checking status of firewalld be part of your troubleshooting toolbox when helping students with strange issues. --contact periodChris Johnson = Winter 2018 Semester =# It appears that doing yum update after May 2018 reintroduces the GRUB issue mentioned in ''' - "tweak" #3''' of '''lab2check2.bashFall 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 provide additional checks including xml dumps be confirmed whether the solution linked to home directory for all VMs and reminder 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 script Belmont) hung up install due to back those items to USB keymissing software repository'''. Also should check if <br>'''centos2Cause''' : due to firewall protocol system implementation in Spring/Summer, it blocked the "yum" protocol, and now has been <u>'''fixed'''</ for 8 GB and /home for 2GBu> system-wide.<br><br>'''FYI:''' '''Murray Saul'''verified that the fix worked by successfully created a VM via network install.<br><br>#qcow <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 used in ops335 not ops235: 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. It wouldn<br><br># <span style="color:red;">'''ATTENTION:'''</span> Verify your CentOS release version using '''rpm -qa centos-release'''t allow students to run the automated scripts. I read somewhere that xfs can mess up If it is '''1708''' <u>and</u> you are using a '''removable hard drive''' with LVM which we talk about in lab5boot issues then do the following: copy '''grubx64. For next time, I will efi'''add in requirement in lab2 signoff 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 students show 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 all VMs 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/etcBOOT 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</fstab syntaxhighlight><br><br># In Lab2 (both versions), change from downloading raw image file (.img) to qcow2 file, and call it sample_test_image to ensure ext4 fs'''get student to launch and login a sample version for exposure for future practical tests. Perhaps checking script can be modified <br><br># For next time semester add in procedure for SSDs to check create a duplicate image file for that..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= #It would There seems to be nice a procedure that works if you are booting Centos7 from your removable SATA drive in your labs and it doesn't connect to rearrange the content for lab5 to Internet...<br>Note: If you cannot connect, you should see on the top right-hand corner before you login such as: '''discuss df <span style="font-h and space concerns 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"><uli>firstQuickly 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.</uli><li>Wait a few seconds, then flow into LVMpress the power button again. This would provide 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 better few seconds, the symbol on the top right-hand side should appear like: <span style="flowborder-color:black;border-width:2px;border-style:solid;" > &nbsp; &nbsp; </span>.<br>This symbol means that you can connect to reinforce student understandingthe 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'''. Shell script at end would remain at end t help Mark but the advice given on this thread might be relevant to show how to use crontab to automate (flagsome) space issues.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/>#Good idea We keep (but rename to '''expand shell script check for ALL something more appropriate) the existing HDD option in OPS235 labsbecause 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. Student would be required to show same information PLUS So no VMs inside a VM stuff for them, except maybe name the results labs from running the checking shell script'external HDD to 'using your own laptop'or some such.<br/><br/>#Good idea to 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: '''review study questions at end of each labyum install initial-setup initial-setup-gui gnome-initial-setup''' . You might have to see if they are applicable reboot and agree to each labthe license conditions at firstboot.<br/><br/>#Would be neat 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 '''create prezi slide shows for each lab preparation share all of your cores with Windows and VMware (for classc7host)'''. This would be <br /><br /> =Fall 2016= # Lab 1: Unusual problem of network not showing up in sync with OPS335 coursec7host VM. Online slides can be exported to PDF files Happened because I had not enabled a second network adapter in VMware Workstation Pro (use Team as wellthe type).<br><br>#Would Change all VM sizes to be helpful at least 20GB because some (lab 2 VMs) still say 15GB and they cause problems during installation for a script or program to check all links in all CentOS 7.2<br><br># Keep consistent lab1 checking scripts for ALL OPS235 instructors (OPS335This semester was exception for Mark F., etc) WIKIs due to check caching problem showing older partitions for non-working linksprevious semester). This would allow course overseer <br><br># I think in future (based on scripting questions I gave on midterm) that we will need to run just prior add to the start questions section of the semester and labs something to do with shell scripting - even a simple walk-through. This can be incorporated into the startup checklistfuture quizzes.<br><br>#Some students note different vg name VMware gets odd naming for interfaces, for example ifconfig in VMware on CentOS 7 I get this (like centos instead of centos_centos2among other network setup). Solution The problem is to get students to issue vgs to obtain vg namethey've switched from the interface naming. Should investigate why this There is happening to prevent (ega workaround in CentOS FAQ: https://wiki. shell script check at end of a lab)centos.org/FAQ/CentOS7<code>eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 </code><br><br>#Check I noticed that some students have a different volume group name for centos2 than centos_centos2<br>I suspect it is that students didn'''mailx''' package t follow instructions when installed (lab5 example) creating the centos2 VM by specifying the correct hostname: centos2<br>This could be corrected by including centos2 being checked for OPS235 to see why correct hostname in lab2 checking script, but not sending mail time to demo do that script for this semester.<br><br># Add youtube video on how LVM works for a lower threshold point lab5 notes<br><br># Check learning outcomes and topic outline match for file space usage.OPS235 course<br><br>#Method For OPS235 Assignment #2, remove references to better explain in lab7 tunnelling via local ports chkconfig command (eg. show some command of available portsdeprecated), etc) should use systemctl status service- example:name<br><br>   == CentOS 7 VM (VMware) Known Issues ==HP Z230 machines on campus# Not getting network interface in CentOS (VMware network configured to using NAT). Solved (sometimes) by adding another network interface and setting that interface to VMnet8# USB failure from Windows host. Could this be due to bad USB cable, but one student reported Windows on HP Z230 automatically unmounts the USB drive while the VM was running thereby freezing CentOS in VMware == Lab 5 suggestion (received from a student) == Create a virtual disk /dev/vda in centos2 and use that virtual disk (vda) instead of /dev/sda (so use '''fdisk /dev/vda''' instead of using '''sysctl net.ipv4.ip_local_port_rangefdisk /dev/sda'''<br>net).ipv4This makes Lab 5 easier to handle accidental corruption students might make while doing that lab thereby destroying their centos2.ip_local_port_range This might require Lab 5 checker script to be tweaked to work with /dev/vda. == Lab 7 Issue == 32768 61000<br>(But where does that fit in  Some students could only get their labs to work with using 20808?)the browser after they did this: iptables -I INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT == Assignment 2 ==