Prelude - in a most respectful way - I have no idea what you're talking about - kinda like jumping into a conversation half way.
Could you please explain from the beginning - covering the following items, at minimum:
Used data (or perhaps available space) on what - a removeable harddrive, a USB flash stick??
What data are you using?
What were you trying to do / or what were you tryng to do?
Explain it like you were talking to someone who has no idea what you've been doing or trying to do?
Maybe then, we can help.