OK, I'm just trying to guess on what you're trying to ask but here's my reply. Hope it's what you're asking.
Yes it's true that a server can have 12TB of storage.
One thing tho... it would be extremely stupid to have so much space. If you have 7TB of storage and have about 7000 users, I can assure you that your server would be a turtle slow (unless nobody uses it). Traffic would be so heavy that sometimes the server (no matter the configuration) will not be able to handle such a load.
As for traffic, yes it's possible for the server to have traffic. The line that the server is using would have to be dedicated to the server itself as traffic from 7000 users is not a simple bit but a HUGE LOT.
I also seriously doubt that any servers would be good enough to hold 7000 users. Either you're looking for trouble or you're just waiting for a disaster to happen.
Either way, it's possible to have such a server but where's the logic in having it?
Hope that's what you're asking and that I did answer your question.