HW10
released: 04/21, 9:00
due: 04/27, 23:59

Answer the following questions.
Submit your answers to Canvas assignments. There is an entry for this homework.


1. Redo logging (4 points)

Read notes Week14b about the five steps of redo logging.
fs was running one transaction, mkdir("/tmp/a", 0777), and then crashed.

Questions:

 1.a The crash happened when mkdir was doing step3 ("write to journal").
     Later, fs finishes a recovery. Does "/tmp/a" exist in fs? Why?


 1.b The crash happened when mkdir was doing step5 ("checkpointing").
     Later, fs finishes a recovery. Does "/tmp/a" exist in fs? Why?



2. Undo logging (4 points)

Read notes Week14b about the four steps of undo logging.

Questions:

  2.a Does step2 have to wait for step1? Why?


  2.b Does step4 have to wait for step3? Why?



3. Authentication (1 point)

Please write down an example of authentication in real-world non-CS scenarios.




4. Feedback (1 point)

This is to gather feedback. Any answer, except a blank one, will get the piont.

  3.a  Please state the topic or topics in this class that have been least clear to you.

  3.b  Please state the topic or topics in this class that have been most clear to you.