CAS Computing Services
How does a computer teaching lab work?
Computer teaching labs in the College of Arts and Sciences are developed with the following guiding principles in mind:
- Every computer in the lab should have the same software on it so that any student can sit down at any machine and be able to complete their assignments.
- Every computer in the lab should look exactly the same and have everything in exactly the same spot to support the goal above.
- Every computer in the lab should go back to exactly the way it was after a student is done with it.
- No personal files should ever be stored on the hard disk of a lab computer and all temporary files or user profiles created on a lab machine should be removed at the end of every user session.
How do we do it?
First off, every computer in the lab is exactly identical. This makes it possible for us to set up one machine exactly the way we want it, then copy that configuration to every other machine in the lab. Departments cannot buy additional machines down the road because they won't be exactly the same as the original machines; breaking the lab management model.
Secondly all lab computers use the UVM online directory to authenticate those attempting to use them. This does two things: a) we are sure that our resources are used by those entitled to them and b) we have a record of who was using a particular machine at a particular time in case there are problems, legal or otherwise.
Lastly we use software to "refresh" the computers back to the way they originally were when the student first sat down. The methodology for doing this varies but in general a "master" disk image exists somewhere, either on the local hard disk or on the network, and the machine compares itself against that master image, reversing any changes to the machine. This is why changes to the lab configuration are extremely labor intensive: not only do we need to make sure that x change works as intended but we then have to copy this revision out to every other computer in the lab. This can take up to an hour and a half per computer.
This is a game of trade offs: in order to gain administrative control of these machines and thereby make the lab a reliable and consistent environment that is easy to teach in, we must sacrifice some flexibility.
Last modified September 12 2012 03:30 PM