Shows your server space (free and used) as a funky Pie Chart in your backend. It also shows a percentage bar in your WordPress dahsboard.
/wp-content/plugins/directory. Please do not rename this folder.
The Plugin can tell you how much space you're using, but it doesn't know how much space you're ALLOWED to use. Hence it can only display the progress bar and pie chart diagramme if you honestly tell it. You should always be honest by the way, even with plugins ;-)
To do so, go to Dashboard - Disk Space Pie and type in the amount of web space you're allowed to use. Say you have 1GB of web space, put in 1 and hit Save Changes. Easy.
If you know your value in MB, you need to divide this value by 1024 to arrive at the equivalent GB value. For example, 100MB divided by 1024 is 0.09765625 - that's the value to use in the box. You get the drift.
If you enter a number smaller than the amount of space you're using, you'll see something like 105% space free - which obviously isn't what you want. So don't do that.