% CST8207 Week 10 Notes – Midterm #2 Analysis, Permissions, Software and Package Management % Ian! D. Allen – – [www.idallen.com] % Winter 2015 - January to Apil 2015 - Updated Sun Mar 22 22:54:02 EDT 2015 Readings, Assignments, Labs, Tests, and ToDo ============================================ - Read (at least) these things (All The Words): 1. [Week 10 Notes HTML] – this file – **Read All The Words** 2. [Unix Modes and Permissions, whoami, id, groups, ls -l, chmod] 3. [Permissions masking with umask, chmod, 777 octal permissions] 4. [Unix/Linux Software Package Management: yum, rpm, and tar] 5. [List of Commands You Should Know] 6. [Video Tutorials on Lynda.com] - Create your [lynda.com] account and watch [Unix for Mac OS X Users] - **4. Ownership and Permissions 34m 58s** - Who am I? 4m 3s - `whoami` - Unix groups 1m 52s - `groups` - File and directory ownership 6m 41s - `ls -la, chown, sudo` - File and directory permissions 4m 27s - `rwx` notation - Setting permissions using alpha notation 6m 49s - `chmod` - Setting permissions using octal notation 3m 49s - The root user 1m 57s - sudo and sudoers 5m 20s Assignments and Lab work this week ---------------------------------- Check the due date for each assignment and put a reminder in your agenda, calendar, and digital assistant. - Read All The Words, Do, and then Submit via Blackboard: - Bonus (optional) [Assignment #04 HTML] – the VIM text editor (extended due date again) - [Assignment #08 HTML] – CentOS virtual server installation - Bonus (optional) [Assignment #09 HTML] – Midterm #2 corrections - There is a checking program available to check your file format for this bonus assignment, but only people who Read All These Words will know about it. Wrong format means no marks. - [Assignment #10 HTML] – setting permissions, mode, umask - Really do **Read All The Words**. You don’t get a second chance to get it right. - Work on the above assignments in your lab period; ask questions. - [Worksheet #08 ODT] – Linux file system permissions (modes) - This Worksheet is a prerequisite for the next assignment. - [Worksheet #08 PDF] – Linux file system permissions (modes) - [Worksheet #08 HTML] – Linux file system permissions (modes) - `chmod, ls -lid, umask` Tests and quizzes ----------------- For full marks, read the [Test Instructions] (all the words) before your final exam. 1. All Quizzes are open until the Final Exam, then they are closed. - Quizzes are random samples and thus do not cover all of the questions in the practice test PDF file. Do the PDF file to be fully prepared. 2. Final Exam: 180 minutes; Tuesday April 21 11am to 2pm in room C144 - Take a bathroom break before you sit down for three hours! - A draft third set of practice questions is posted. See [Practice Tests and Answers]. - The final exam emphasizes material after the second midterm test, but it covers the whole course and therefore includes material from **all** the practice question sets. Midterm Test #2 Analysis ------------------------- 90/107 people wrote the second midterm test. - Number of students who entered their own name incorrectly on the mark-sense form (usually by shortening it): `5/90` *(Your mark is zero until you fix your form.)* - Number of students who had a missing, incorrect, or unrecognized test version number on the mark-sense form: `7/90`. *(Your mark is zero until you fix your form.)* - Number of students who got question `#45` wrong even though the answer was given in the **Test Instructions** printed at the top of the test: `4/84` - Class scores for 89 students: 100 100 100 97.8 97.8 97.8 97.8 97.8 95.6 95.6 95.6 93.3 93.3 91.1 91.1 88.9 88.9 88.9 88.9 86.7 86.7 86.7 86.2 84.4 84.4 84.4 84.4 84.1 82.2 82.2 82.2 82.2 82.2 82.2 81.9 80 77.8 77.8 77.6 75.6 75.6 75.6 75.6 73.3 73.3 73.3 71.1 68.9 66.7 66.7 66.7 64.4 64.4 64.4 62.2 62.2 62.2 60 60 58.5 57.8 55.6 55.6 55.6 53.3 53.3 48.9 46.7 44.4 40 38.8 35.6 35.6 33.3 28.9 26.7 26.7 24.4 24.4 24.4 20 20 20 17.8 11.1 0 0 0 0 0 #-89: Pass 66 (74.2%) Fail 23 (25.8%) #- 36 A (40.4%) 13 A- 8 A 15 A+ #- 11 B (12.4%) 1 B- 7 B 3 B+ #- 12 C (13.5%) 5 C- 3 C 4 C+ #- 7 D ( 7.9%) 0 D- 5 D 2 D+ #- 23 F (25.8%) 20 F- 1 F 2 F+ #- 90% - 100% 15 *************** #- 80% - 90% 21 ********************* #- 70% - 80% 11 *********** #- 60% - 70% 12 ************ #- 50% - 60% 7 ******* #- 40% - 50% 4 **** #- 30% - 40% 4 **** #- 20% - 30% 9 ********* #- 10% - 20% 1 * #- 0% - 10% 5 ***** - You can see the errors in [Midterm Test #2 PDF]. From the Class Notes link on the Course Home Page ================================================= - Review last week. Did you do everything assigned last week? From the Classroom Whiteboard/Chalkboard ======================================== - We do permissions this week. Know your **minimal** permissions for each action from [Worksheet #08 HTML]. - Some draft practice questions for the final exam are posted. See [Practice Tests and Answers]. - [Assignment #10 HTML] is ready. Real Sysadmin Work ================== - [VMware sued for failure to comply with Linux license] - *VMware has been accused of violating Linux’s open-source license, the GPLv2, in its ESXi product line.* - [The Future of Linux Storage] - *Facebook, of course, runs on Linux. To be exact, Facebook runs the 3.10 and 3.18 Linux kernels on an internal distribution, which is based on CentOS.* - The [Future of VIM] - [NSA hunts System Administrators] - The full documentation on basic commands (better than `man` pages): - Google propels Linux to the top - Five-year-old passes Microsoft Certified Professional exam: - Studying for a Linux Certification Exam : - [How to fix any computer] Install a differnet browser – be a better employee -------------------------------------------------- **Analysis:** People Who Use Firefox Or Chrome Make Better Employees *In the world of Big Data, everything means something. Now Joe Pinsker reports that Cornerstone OnDemand, a company that sells software that helps employers recruit and retain workers, has found after analyzing data on about 50,000 people who took its 45-minute online job assessment, that people who took the test on a non-default browser, such as Firefox or Chrome, ended up staying at their jobs about 15 percent longer than those who stuck with Safari or Internet Explorer. They also tended to perform better on the job as well. Chief Analytics Officer Michael Housman offered an explanation for the results in an interview with Freakonomics Radio: “I think that the fact that you took the time to install Firefox on your computer shows us something about you. It shows that you’re someone who is an informed consumer,” says Housman. “You’ve made an active choice to do something that wasn’t default.” But why would a company care about something as seemingly trivial as the browser a candidate chooses to use? “Call centers are estimated to suffer from a turnover rate of about 45 percent annually (PDF), and it can cost thousands of dollars to hire new employees,” says Pinsker. “Because of that, companies are eager to find any proxy for talent and dedication that they can.”* Why the modern world is bad for your brain ------------------------------------------ *In an era of email, text messages, Facebook and Twitter, we’re all required to do several things at once. But this constant multitasking is taking its toll. Here neuroscientist Daniel J Levitin explains how our addiction to technology is making us less efficient.* Locked out of the Course Linux Server I --------------------------------------- Someone local tried to log in to the CLS with the `root` account and got their IP address locked out: Mar 14 21:47:21 Failed password for root from 70.24.165.106 Mar 14 21:47:33 Failed password for root from 70.24.165.106 Mar 14 21:47:46 Failed password for root from 70.24.165.106 Mar 14 21:47:56 Failed password for root from 70.24.165.106 Mar 14 21:48:01 Failed password for root from 70.24.165.106 Mar 14 21:48:04 Failed password for root from 70.24.165.106 Mar 14 21:48:06 Failed password for root from 70.24.165.106 Mar 14 21:48:16 refused connect from bas2-clarkson16-1176020330.dsl.bell.ca (70.24.165.106) I told you not to do that. Read All The Words. Locked out of the Course Linux Server II ---------------------------------------- Someone else local tried to log in to the CLS with the `root` account and got their IP address locked out: Mar 18 20:47:07 Failed password for root from 70.54.60.28 Mar 18 20:47:16 Failed password for root from 70.54.60.28 Mar 18 20:47:28 Failed password for root from 70.54.60.28 Mar 18 21:33:29 refused connect from orlnon0604w-lp130-01-1177959452.dsl.bell.ca (70.54.60.28) I told you not to do that. Read All The Words. Attacks on the Course Linux Server ---------------------------------- - Count the attacks: `fgrep -c "refused connect" /var/log/auth.log` - Another way to count the lines (less efficient): `fgrep "refused connect" /var/log/auth.log | wc` - Only show the last 10 lines: `fgrep 'refused connect' /var/log/auth.log | tail` - See the current list of *evil* host IPs: `less /etc/hosts.evil` * * * * * ![Bye Bye Data – rm -rf *] ![Read All The Words by Alex and Colin] ![Take Notes in Class] -- | Ian! D. Allen - idallen@idallen.ca - Ottawa, Ontario, Canada | Home Page: http://idallen.com/ Contact Improv: http://contactimprov.ca/ | College professor (Free/Libre GNU+Linux) at: http://teaching.idallen.com/ | Defend digital freedom: http://eff.org/ and have fun: http://fools.ca/ [Plain Text] - plain text version of this page in [Pandoc Markdown] format [www.idallen.com]: http://www.idallen.com/ [Unix Modes and Permissions, whoami, id, groups, ls -l, chmod]: 500_permissions.html [Permissions masking with umask, chmod, 777 octal permissions]: 510_umask.html [Unix/Linux Software Package Management: yum, rpm, and tar]: 520_package_management.html [List of Commands You Should Know]: 900_unix_command_list.html [Video Tutorials on Lynda.com]: 910_lynda_index.html [lynda.com]: http://algonquincollege.com/onlineresources/mobileStudent/lynda.htm [Unix for Mac OS X Users]: http://www.lynda.com/Mac-OS-X-10-6-tutorials/Unix-for-Mac-OS-X-Users/78546-2.html [Worksheet #08 ODT]: worksheet08.odt [Worksheet #08 PDF]: worksheet08.pdf [Worksheet #08 HTML]: worksheet08.html [Test Instructions]: 000_test_instructions.html [Practice Tests and Answers]: PRACTICE_TEST_README.html [Midterm Test #2 PDF]: midterm2.pdf [VMware sued for failure to comply with Linux license]: http://www.zdnet.com/article/vmware-sued-for-failure-to-comply-with-linuxs-license/ [The Future of Linux Storage]: http://www.zdnet.com/article/linux-storage-futures/ [Future of VIM]: https://github.com/neovim/neovim/wiki/Introduction [NSA hunts System Administrators]: https://eff.org/r.yby9 [How to fix any computer]: http://theoatmeal.com/blog/fix_computer [Bye Bye Data – rm -rf *]: data/rm-rf.jpg "Bye Bye Data -- rm -rf *" [Read All The Words by Alex and Colin]: ian_algonquin2014_read_all_the_words.jpg "Photo by Alex Lemoine and Colin Hough" [Take Notes in Class]: data/remember.jpg "Take Notes in Class" [Plain Text]: week10notes.txt [Pandoc Markdown]: http://johnmacfarlane.net/pandoc/