About storage limit

Hi

I have an instance of windows server 2012, with an sql server and a web application, but for now it's ok, but in the future when my information will grow up my storage capacity don't will be enought for this.

Now I have 1TB  in RAID 10 with 4 disk of 500GB, my server just support disk of 2TB, I think to buy 4 disk of 2TB, for now I fix the problem but in the future how can I solve this?