Allot space to individual registered user
A disc quota is one thing but also checking user-content in the db could be tricky :-). Never done something like this but here's what I would try:


use file_save_upload() to validate the upload. Part of the validation should be
the use of file_validate_size() and
file_space_used() to check the used space.


But as I said that checks only stuff inside the files table. No other content (text inside fields, cached content, thumbnails...) will be handled.