How do you save a users content to your sites directory?

Say you have a website that allows users to 'write short stories' using the sites different features and what not. Each user creates their own profile and signs in to use this site. What if, half way through a user creating their 'short story', the user has to stop what they are doing for whatever reason and log off. The most appropriate thing, at this point, would be to have a 'SAVE' option to save the current work they have so that whenever they come back and sign back in, there 'SAVED' content will be ready accessible. HOW and WHERE do you save this data? My first thought was to insert the data via mySQL, the same way I do when handling a new user sign up. But upon some digging, I read that it's not a good idea to insert that much data via mySQL (since the data that would need to be entered would be a super large blob of text). Upon more digging, I learned that you could insert the url's (which in turn point to the saved content) but again, WHERE do you save this content? On your websites own directory? and how would you do that? Any help is appreciated.