Virtual Exam

Work in Progress or Draft only

Please read the documentation of virtual exam

The way the virtual exam white listed software (etc/vx.conf) will be rewritten early in Term 1 to better cope with software changes on CSE computers.

Useful scripts

• ~give/stable/bin/prac_install_vx <from_prac> <to_prac>

  • set up a standard virtual exam environment

  • if <from_prac> != <to_prac>

    • copy <from_prac> from virtual directory if exists

    • copy <from_prac> from gaol directory otherwise

  • else

    • copy <from_prac> from gaol directory

• priv passwd
  • change the vxN (eg vx6) password before and after the exam with this script
  • add the class account public key to the exam account (eg cs2521exam)

• priv chown <path_wildcard>

  • change work directory ownership from 90<uid> to the exam account to access students' files

  • after changing ownership, students can't start the exam. so, do this only after the exam has finished.
• ~give/stable/bin/vx-conf-product.pl
  • strace the command
  • feed the output of strace to this script
  • add vx.conf files as arguments
  • script will output files that are missing from the config files
• dpkg-query, apt-cache depends
• find files needed by gcc

  apt-cache depends --recurse --no-pre-depends --no-recommends --no-suggests --no-conflicts --no-breaks --no-replaces --no-enhances gcc | egrep -v '^ ' | xargs dpkg --listfiles | egrep -v '^($|/lib|/bin$|/usr($|/bin$|/(lib|share)))'| sort | uniq | less

Tips

• when the exam crashes after you authenticated with your zid, check the stderr.log file under <exam_account>/var directory. Look at the latest directories.

  marimba % ls -lt ~/var | head -5
  total 988
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 13 06:59 marimba-25528
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 12 20:49 wagner-7800
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 12 20:33 vx4-45795
  drwxr-xr-x 2 cs9024exam cs9024exam 4096 Feb 12 18:39 vx4-34624

• after changing ownership of the work directories (to exam account), you can't start the exam with the same work directories.
  • create a new toplevel work directory.

    cd ~/exams/18s2supp
    mv work work.19dec
    mkdir work
    chmod 1777 work

  • or remove the student's work directory

    cd ~/exams/18s2supp/work
    priv chown z5555555
    rm -r z5555555