CS 450: Operating Systems


Posted: inode filesystem computation practice problem

Since no practice exam containing a sample inode computation is to be found on the new-ish website, I've posted a sample problem to help you prepare for the final exam.

Posted: MP4

MP4: Improving the Filesystem has been posted!

Posted: MP3

MP3: Synchronization with Semaphores has been posted!

Posted: midterm exam topics list

Please use this list of topics as a study guide for the midterm exam.

Fixing "default: Warning: Connection timeout. Retrying..."

A number of students have reported being stuck at the "default: Warning: Connection timeout. Retrying..." message when doing a "vagrant up". Most have been able to fix this by enabling the Intel processor virtualization option in their BIOS. A number of laptop vendors (notably Lenovo and Sony, as far as I've been able to tell) have the setting off by default. To access your BIOS you'll usually hit the Esc or F1 key during the boot sequence --- look for a setting labeled "virtualization" or "Vanderpool". Turn it on, reboot, and try "vagrant up" again.

xv6 machine problem 1 posted

The first xv6 machine problem is now available. I'll do a quick demo in class, but please read the writeup and get started asap!

Assignment 1 scores posted

You'll find your scores posted on Blackboard. It appears, unfortunately, that the system swallowed up my comments, so I'm working on getting those inserted back in. Please check back or just e-mail me if you'd like detailed feedback sooner.

Assignment 1 is out

The first assignment is live — please submit your PDF via Blackboard by Saturday, May 23rd (by end of day).


This schedule is tentative and may be updated:

May 18

May 20

May 25

May 27

June 1 - June 3

June 8

June 10-15

June 17

June 22

June 24


Please note:

  1. Tanenbaum-Torvalds Debate (30 points)

    • Due: May 23 (via Blackboard)
  2. Machine problem 1 (xv6): Adding a system call (30 points)

    • Due: June 7 (via BitBucket --- see the writeup for submission details)
  3. Machine problem 2 (xv6): Kernel threads (50 points)

    • Due: June 14 (via BitBucket)
  4. Machine problem 3: Synchronization with Semaphores (45 points)

    • Due: June 28 (via Blackboard)
  5. Machine problem 4 (xv6): Improving the Filesystem (30 points)

    • Due: June 28 (via BitBucket)



Primary reference materials

Source code repositories

Simulators / Emulators

Supplementary materials

Sample Exams / Problems