Recently, I encountered a problem where my site's data was growing rapidly. I wanted to find out which list or library is using how much disk space (storage). I found out an easier option to list all the lists/libraries in the site and their corresponding storage space.
You just have to append "_layouts/storman.aspx" at the end of your site address. But when I checked for the first time, the data was not accurate. But then I saw a message at the top of the page which said data displayed may not be up to date. Revisit the site to get more accurate data. So when I revisited the page. I was able to get accurate information.
This might help some one...-Vighnesh Bendre