The site is currently configured to store all files uploaded through the wiki to the directory /public_html/wiki/uploads/common except for the file uploaded through the Joyful Noise Media group, which are stored in /public_html/wiki/uploads/JoyfulNoiseMedia.

Changes made to uploaded files are not tracked and new uploads of an existing file (i.e. uploading a file with the same name as an existing one) will overwrite the original file.

The space used for uploads is simply the size of the file. There really is no additional overhead.