Im using Cyanogen 10.2.1-d2tmo and have a 64gb SD card. Whenever I delete files on the SD card it seems like they are deleted, but the space is not given back. The "system data" on the SD card is very large, almost 21GB right now. I think thats the problem. How do I delete/clear it out? I cannot find it anywhere in a file manager. I installed "sd-maid" and "rom toolbox" and didnt get anywhere.