Hi Ben
The users and the concept behind the LMS decide how much data will be uploaded. Note that the software (OS to Moodle) and the database together will take up a tiny fraction of the harddisk.
Then the space requirement - 1 TB/user in your case! - is not a constant. It all depends on how much content do you have at the beginning, how do you plan to grow, is this a purely online institiution or it just supports a conventional school, what type of instructional media will be used (HTML. PDF, sound, video, ...), what type of assignments will be given (will the students make films and upload them to Moodle), ...
1 TB sounds like an overkill to me. I know a couple places with around 1000 users. Their moodledata varies from 2 - 12 GB. And how are you going to backup a TB? I mean, to keep a couple of daily and weekly versions.
No point in planning for 10 years, by that time you need a new server anyway.
Hardware and performance
Buying an in-house server
This discussion has been locked so you can no longer reply to it.