This appendix is intended for any person responsible of maintaining the system hardware and installation. It describes various tasks that should periodically be done to ensure smooth operation of the system.
The CAN-8 system is designed to operate in a client-server environment.
The server software typically runs on Windows NT (workstation or server),
Windows 2000 (workstation or server), Windows XP and windows 2003.
using the Intel based platform. The client software may run on either
Windows 95/98, Windows NT, Windows 2000 and Windows XP.
In order to operate, both the client and server machines must have TCP/IP loaded and properly configured. The server system may be placed behind a firewall if UDP ports 17180-17190 are left open to access the server or if the firewall is configured to redirect these packages from it's outside IP address to the CAN-8 server.
The CAN-8 server process provides its own security between client stations and itself. This includes login authentication, user management and enforcement of single logins. The CAN-8 server process may run either as a service process or an application on the server. The program does not display a window so there is no information to observe on the server itself. All information regarding users and operation of the system is accessed via the client station.
The CAN-8 server may run alongside other applications on the server machine, however care should be taken to ensure that the server has enough CPU power and memory to handle both. The server process will consume a maximum of 60 MBytes while running. Additional memory in the server will improve performance as it will be used as a disk cache by NT itself.
The client software may be provided as a compressed archive. The size of the software without the online manual is approximately 3.5 Mbytes. The online manual raises this size to 10.5 Mbytes.
The system consists of regular files that are typically stored under
the \SVSYS\... directory. While the server program is running,
various files throughout this directory will be open for writing and
reading. For backup purposes, the files may be read at any time as
database and student tracking files are typically appended to and not
modified in place.
The backup procedure used must be capable of reading files that are currently open for writing by another process. Also, the backup program must not ever open any file with write access as it will potentially prevent the server program from being able to write to the same file at the same time.
It is recommended that a full system backup be used rather than an incremental backup due to the large number of files that are modified during the operation of the system. Each incremental backup may be as large as the full system backup in this case.
As a resource, the disk space on the server will be consumed by the
system at a fairly high rate. The exact amount consumed will depend
on the number of students performing recordings, the length of the
recordings and the amount of static course material that has been
recorded on the server. In most cases the student recordings will
far exceed the space used by the course material, as well, the amount
of course material does not increase constantly, where as the student
recordings may do so.
The approximate disk space used by students for recordings may be calculated as follows for the purposes of example:
Average minutes spent by students recording per session X Number of students using system per day = Total minutes of recording time per dayIf you take this total and divide by 60 minutes to the hour and then multiply the number of hours 15 Mbytes you will have the daily total storage requirements for the system. For example:
30 minutes per session recorded X 150 students per day = 450 minutes per day 450 minutes per day = 7 hrs per day = 105 Mbytes per day Assuming classes 5 days a week = 525 Mbytes per week Per month = 2.1 GBytes per month Per 4 month term = 8.4 GbytesAs you can see, the amount of disk storage for students climbs rapidly.
At the end of each term or year, it is sometimes desirable to remove all the students from the system. There are two methods of accomplishing this. Both methods rely on using the REFRESH option in an import student registration file. The two types have different effects:
This option removes all students from the system but leaves instructors, and their class names intact. This option is useful between terms for when it is not desired to re-create instructors or class names.
This option removes all students, classes, assignments, and instructors.
The MASTER user is remove and re-created with the default password of
PWORD. This option is useful at year ends when instructors and
class assignments will change. This option also has the side benefit
cleaning up the users database file and re-compacting it.
In both of the above cases, the \SVSYS\DELETED directory should be removed to free the disk space that is used by student responses.
While operating the system tracks various internal parameters in
a file called SERVER.LOG that is created in the same directory
as the NTSERVE.EXE program. This file can be examined to
monitor the system operation. This file must not be opened for
write access while the NTSERVE program is running as it will
cause the NTSERVE program to wait until exclusive write access
This file is updated approximately every 10 minutes when the system is idle and more often during periods of heavy use.
If problems are encountered with the operation of the NTSERVE program, it is wise to make a copy of this file for examination later.
Next Appendix - Networking Information
Previous Appendix - System File Layout