I too haven't used moodle in a "high traffic" situation, may be in the near future.
Just 2500 students alone tell much. I assume they all are enrolled in the moodle system.
There are other figures you have to get, to do an accurate estimate. Like:
- How many "courses" will the students attend?
- How often?
- How many students will be logged in at the same time, say at peak times?
- What is a typical course? How much data it will contain, how are they "recycled" (meaing, will they be repeated on a semester basis, for example?)
Ultimately, you have to come down to:
- amount of data storage
- throughput in terms of
* harddisk subsystem
- CPU processing power
We had a similar discussion just a couple of days ago:
My quick guess is, at the rate of present harddisk sizes and CPU power the storage and processing are not bottlenecks. The network of course, the speed of the harddisk subsystem too, if you have a really _fast_ network.
Of course backups and other fail-over methods are topics you have to tackle separately.