LabMan Examples
Lab Configuration
An example computer lab with minimal equipment and optional external validation host is presented below to give a general idea of how UT-LabMan-controlled computer labs are set up and operate. These are:
Some number of end-user workstations, say 5 Microsoft Windows XP and 5 Apple Macintosh G5 workstations. The UT-LabMan Client software will be installed on these.
A non-public PC is required to run the UT-LabMan Server software, the central component of the system. Many lab administrators choose this to be a Microsoft Windows Server OS, so it can also support file sharing and workstation disk maintenance operations. However this can be any Windows NT-class client or server OS (NT 4, 2000, Server 2003, XP).
The UT-LabMan Console is used to monitor and control the computer lab. It can be run on the Server computer, or from any staff PC.
To support the optional waiting list features, two computers are required. One is a minimal Windows PC running Windows 98 to be the sign-in station. The other is a minimal Macintosh computer to display the workstation assignments information.
The optional external validation system is for validating against a central institutional validation host. At UT-Austin, you can validate against the central UT-EID or campus printing system (PRS) hosts. At other institutions, only validation hosts supporting the rexec (rsh) protocol are currently supported. These include Unix/Linux or VMS (with MultiNet) hosts. (Please contact us if you use other validation schemes.)
Sample Lab Setup
When setting up a lab from scratch, the lab admin first goes through a process of creating a map representing the physical layout of the lab. This layout will be displayed on the Console and WaitList components. Next, one or more workstation groups are to be defined. Groups let you assign names, properties and behaviors to subsets of lab workstations. Most groups have descriptive names that appear on workstation displays ("PC", "Macintosh", "Scanner PC", etc.).
This lab is to have general-use, high-end graphics with scanner, and short time-limit or "Express" workstations. The lab admin has set up UT-LabMan workstation groups to enforce this using the Supervisor Console. Full details for setting up the UT-LabMan system are described in the Administrator's Guide.
User Experience
A user entering the computer lab can walk to any available workstation and log in. Available workstations identify themselves with large text such as "Workstation PC5 is an available Express PC."
- If all the workstations appear occupied, the user should go to the UT-LabMan WaitList sign-in computer, ideally located near the entrance of the lab. Here the user can select a UT-LabMan group and see its available stations, or sign on to its waiting list. The account is checked for validation.
- If a station of the requested type is currently available, the user is notified there. If not, the user should go to a waiting area and watch the UT-LabMan Assignments display.
- When an assignment is made to a workstation, the UT-LabMan Assignments screen displays the user's login ID, the assigned station's name, and the amount of time remaining before the assignment expires. The screen of the assigned station will also display this information and not allow others to log in.
When a user attempts to log in to a workstation, several validation checks occur:
- The UT-LabMan Client first checks with the UT-LabMan Server to see if this user has an overriding Local or Staff account (that is, one that is defined on this lab's UT-LabMan Server).
- If not, and an external host is specified, the client will attempt to validate the user against the external host.
- If either validation is successful, the UT-LabMan Server checks that the user isn't on its revoked user list before allowing the user to finally log in.
- Once the user successfully logs in, the UT-LabMan server records the information in the station and user log files, updates its statistics and status displays, and marks the station as "in use".
If a user restarts a workstation prior to logout, the workstation will be automatically re-assigned back to that user. This prevents the current user from losing the workstation to someone on the waiting list if for example the computer crashes. However, if the current user does not log back in, the reassignment will time-out and automatically log the user out.
When a user logs out, the client informs the UT-LabMan Server and then optionally runs third-party disk clean up software and/or other scripted commands to restore the hard drive contents to their original configuration. This may also involve restarting the workstation.
Once this process completes, the UT-LabMan Server assigns the next waiting user to the workstation. If there are no users waiting for such a station, the client is made available for anyone to log in.
Note that the above description represents only a sample configuration. The UT-LabMan software lets you change much the behavior described above. Additional features are also available, such as the ability to restrict access to departmental users full- or part-time.
