CST8207 Week 07 Notes
File System, Inodes, Hard links, Disk Usage, Symbolic Links, Midterm 1 Analysis

Ian! D. Allen – www.idallen.com

Winter 2019 - January to April 2019 - Updated 2019-03-04 12:06 EST

1 Readings, Assignments, Labs, Tests, and ToDoIndexup to index

1.1 Read (at least) these things (All The Words)Indexup to index

  1. Week 07 Notes HTML – this file – Read All The Words
  2. File System, Inodes, Links – directories, index nodes (inodes), hard links
  3. Hard links – hard links, file system index nodes (inodes)
  4. Disk Usage – Hard Links, Quotas, Finding Inodes
  5. Symbolic Links – soft links work on directories and across file systems
  6. Next Week: Permissions – permissions, modes, whoami, id, groups, ls -l, chmod
  7. List of Commands – Command names you should know, listed by week
  8. Video Tutorials on Lynda.com – tagged by week number
  9. Linux and Sysadmin News in the World

1.2 Assignments this weekIndexup to index

Check the due date for each assignment and put a reminder in your agenda, calendar, and digital assistant. Just like in the Real World, not all due dates are on the same days or at the same times.

1.3 Lab work this weekIndexup to index

1.3.1 Worksheets

Worksheets are preparation for your assignments. You can’t do the assignments without having done the worksheets first, and you can’t do the worksheets without having first read the Course Notes:

  1. Read the web notes. (Please: Read All The Words)
  2. Do the relevant Worksheet(s).
  3. Do the relevant Assignment(s).

Make notes from the worksheets on how each command works. What do the options used in the worksheets mean, for each command? (See the weekly List of Commands.)

Form a small study group to do the worksheets. Each person tries the example given, and you make sure you all get the same answers. Worksheets are not for hand-in; they are not worth marks; the assignments test your knowledge of the lectures and worksheets.

The worksheets are available in four formats: Open Office (ODT), PDF, HTML, and Text. Only the Open Office format allows you “fill in the blanks” in the worksheet. The PDF format looks good but doesn’t allow you to type into the blanks in the worksheet. The HTML format is crude but useful for quick for viewing online.

Do NOT open the Worksheet ODT files using any Microsoft products; they will mangle the format and mis-number the questions. Use the free Libre Office or Open Office programs to open these ODT documents. On campus, you can get a copy here: Course Introduction: Install Libre Office.

Worksheets #04 and #05 require you to have read Shell GLOB patterns and Shell I/O Redirection:

Worksheet #06 is for the optional VIM Bonus Assignment (extra credit):

Worksheet #08 is for the upcoming Assignment 9.

Worksheets prepare you for the upcoming assignments.

1.4 Upcoming tests and examsIndexup to index

This course has two midterm tests (10%, 15%) and one final exam (40%).

Bring your favourite marker to your test

Follow this link to see all your upcoming Quizzes and Tests. The dates are also posted on the Course Home Page and on Brightspace CST8207.

For full marks, read the Test Instructions (all the words) before your midterm tests.

  1. First Midterm test: Done.
  2. Second Midterm test: 45 minutes; 8am Friday March 22 in your 50-minute lecture class in Week 10.
  3. Final Exam: The date is now posted on ACSIS: Tuesday April 23 from 1pm to 4pm in T119.

Midterm tests take place in your one-hour lecture class, not in your lab period.

2 Midterm Test #1 AnalysisIndexup to index

I spent hours correcting your errors and omissions on your test papers. Many of you lost marks for that. Before your next test, carefully re-read the posted Test Instructions. Penalties go up for making the same errors on the next tests.

Here are some statistics for the first midterm test:

The 88 class scores:

100 100 99 97.8 97.8 97.8 97.8 97.8 97 95.6 95.6 95.6 95.6 95.6 95.6 95.6 95.6 94.8 93.3 93.3 92.7 91.8 91.1 91.1 91.1 88.9 88.9 88.9 88.4 88 88 86.7 86.7 86.7 85.8 85.4 84.4 84.4 84.4 84.4 84.4 84.1 84.1 82.2 82.2 82.2 82.2 80 80 80 80 80 75.4 73.3 73.3 72.6 71.1 71.1 68.9 66.8 66.7 62.2 60.4 60 58.5 56.5 55.6 55 55 53.9 53.3 51.1 51.1 50.6 48.9 45.5 44.4 44.4 44.4 42.1 41.4 40.1 36.6 35.2 31.8 28.9 26.7 13.3


88 students: Pass 74 (84.1%)  Fail 14 (15.9%)
 52 A (59.1%)    16 A-   11 A   25 A+ 
  6 B ( 6.8%)     2 B-    4 B    0 B+ 
  6 C ( 6.8%)     3 C-    0 C    3 C+ 
 10 D (11.4%)     3 D-    5 D    2 D+ 
 14 F (15.9%)     9 F-    4 F    1 F+ 
 90% - 100%  25  *************************
 80% -  90%  27  ***************************
 70% -  80%   6  ******               
 60% -  70%   6  ******               
 50% -  60%  10  **********           
 40% -  50%   8  ********             
 30% -  40%   3  ***                  
 20% -  30%   2  **                   
 10% -  20%   1  *                    
  0% -  10%   0  

Please Read All The Words!

3 Notes from the ClassroomIndexup to index

3.1 Commands UsedIndexup to index

Keep a notebook with a List of Commands in it.

  • You need to write down yourself what each command does.
  • Check the updated list of commands each week.
  • I will check for this list in your lab periods.
  • Bring your notes to class! Stop wasting time looking up commands.

4 BONUS Assignment #06 improves your Midterm #1 markIndexup to index

Bonus (optional) Assignment #06 HTML may be done after you get your marks email and question sheet back for Midterm #1. You can use this bonus work to optionally improve your mark on the first midterm test. See the assignment for details on how this works.

Your midterm test question sheet will be brought to the lab section class that you wrote on your question sheet, if it is a valid lab section. See the Prerequisites of Assignment #06 HTML for details.

5 Searching the course notesIndexup to index

I received an email like the text below from a student who was working on a problem for over two hours:

I have spent almost 2 hours on Task 4.6 and I still can’t find the 100 files. […] I think the problem is searching for warez case-insensitive. I know we learned this before, but I just can’t find it in my notes.

This is not good use of student time for two reasons:

  1. Don’t spend more than 15 minutes on a problem! Your time as a student is valuable. See the Course Introduction: fifteen minute rule
  2. I show you how to search the course notes for keywords in Assignment #05 HTML:

You have a search tool that will find keywords inside the course notes. Please use it and save yourself time.

6 Who is using the VIM editor?Indexup to index

This page may take a minute or two to load; be patient: Who is using the VIM editor?

7 TutoringIndexup to index

Many students find that hiring a personal tutor helps them get through the first term. Financial assistance is available. See the Tutoring heading in the Course Introduction.

8 SSH and HTTP Attacks on the CLSIndexup to index

You are not paranoid if they really are out to get you! See the Week 03 Notes HTML for command pipelines to count the ongoing attacks on the CLS.

David Thomson pointed out this recent CBC report on Chinese hacking:

Your job is important. Read All The Words.

9 Locked out of the CLSIndexup to index

When you are locked out, follow the directions in the notes to get your IP address re-enabled.

Take Notes in Class
| Ian! D. Allen, BA, MMath  -  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/

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