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Maebashi Waterworks Resource Center water tower (another limited resource).

VirtualExam (vx)
2019 upgrade - resource limits

The following resources are limited on a per exam-candidate basis. The default values are shown in parentheses:

  1. Number of CPU's available (2),
  2. Memory available (8000 megabytes), and
  3. PID's (process ID's) available (800).

If the default values are not suitable these can be set on a per exam basis in a file called /home/<exam>/currentexam/etc/vxresource.conf. The file permissions must allow read/execute by all.

Below is an example vxresource.conf file.

# ===============
# vxresource.conf - per candidate exam resource limits
# ===============
#
# Location: /home/<exam>/currentexam/etc
# Pemissions: Must be "chmod a+rx"

CPU_LIMIT=4
MEM_LIMIT=10000
PID_LIMIT=1000

These limits are imposed by /home/virtualexam/bin/vxset_resource_limits which is invoked by vxgaolsetup-userhome just before the exam's etc/startup file is run.

Note: CPU limits are imposed by setting scheduler CPU affinity. This may be practically impossible to check inside a gaol if the taskset program is not available.