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Unix Directory Setups, Course Support Models, Administration

The ACMS Help Desk is available to assist instructors and TAs in all facets of using ACMS instructional facilities.

Two Course Setup Models

ACMS provides two distinct models for class account set-ups.  Wherever possible, students are given accounts that match their OCE or personal account.

Model 1: Course-specific accounts

This model is used mainly by engineering courses utilizing space on ACMS Unix-based hosts.  Each student is given a special purpose account for the class. The accounts are named after the class (subject, course number, and semester), with two extra letters appended to the end to make each student's account name unique. For example, me10fxx could be a student account for MAE 10 during the fall semester.

Under this model, an instructor has a high level of control over the accounts, including the ability to switch user (SU) to student accounts without using a password.  More details: Course-Specific Models.

Model 2: Open Computing Environment (OCE)

Eligible students open a personal OCE account which they are expected to use for all OCE compatible classes in which they are enrolled. The account receives allocations of computer time and disk space for each OCE compatible class. Any leftover computing resources may also be used for extra-curricular purposes.

The OCE account is named after the student: usually the first initial of their first name followed by up to the first seven letters of their last name (e.g. jdoe).

The SU authority which allows an instructor to "switch user" to a student's account without a password is not available under the OCE model. In contrast with course-specific accounts set up under the traditional model - in which each account is designated for one class and one class only - students use their OCE accounts for multiple classes. In order for the students to manage and control the account and its files to complete assignments for various classes, OCE accounts must remain fairly autonomous. Instead, the prepfile mechanism provides the instructor with a means to tailor the student's shell environment and to broadcast messages for the class. The Turn It In program addresses the issue of homework collection.  Additional resources:

OCE Course Set-up

Account limits

Accounts have limits on various resources.

Processor Time and Connect Time

On Unix systems, accounts are allocated a number of Computing Units (CUs) each week. The processor time and the connect time (from login to logout) that students use is charged against their weekly allocation of CUs at a rate of one CU per hour of connect time, one CU per hour of processor time on a workstation, and 10 CUs per hour of processor time on a server.

If the student runs out of CUs, the account is suspended until the next allocation (Friday morning). This rarely happens in the case of instructional accounts because the course related allocations are fairly generous.

There are mechanisms to limit the amount of processor time individual jobs consume on Unix systems. These mechanisms help stop runaway jobs (for example, resulting from an infinite loop in a program) and protect the student from the resulting depletion of Computing Units.

Disk Space

Accounts have disk space limits (quotas).

Instructors should contact the ACMS Accounts Office to request quota increases for a class or specify instructions on their Cinfo request. In most cases increases can be easily accommodated, but may be more difficult for large classes. Sometimes it is necessary to check the accounts of students who are running out of space to make sure that space is not being wasted by such things as core files, executable files that are no longer needed, or recreational files unrelated to the course.

See also Quotas.