I have read many, many post regarding truecrypt and hidden volumes and none of the posts appear to answer my questions so I thought I would post specific questions here and hope someone can answer them. I have a 2tb usb external drive. I just completed encrypting the entire drive as one volume (no partitions). I am setting up a hidden volume. I am confused about what I can do with the outer volume and what size I should allocate to the hidden volume. I just placed 50 GB of photos and videos in the outer volume. Truecrypt wants to know what size I want the hidden volume. Here are my questions. Of the 2TB (not exactly because of the overhead I know), but of the 2TB if I only allocate 1TB to the hidden volume, is it safe to use the other 1TB of the outer volume, or will I risk overwriting the hidden volume If I do make the hidden volume 1TB, and use the following procedure to protect the hidden volume http://www.truecrypt.org/docs/?s=hidden-volume-protection , it mentions that it errors out and doesn't write to the outer volume. So am I to believe that I should just make the hidden volume as large as possible because I will not be able to use the outer volume after I create the hidden volume? How would you recommend that I use the 2TB space. Obviously I do not have 2TB of information I need hidden, I only want to plan for the future and not have to do this again. Right now I can see myself using 300-500GB. Can you safely change the hidden volume size after you have added data to it and there is data in the outer volume? Obviously I do not want to have to use most of the drive as a hidden drive, but overwriting the data concerns me.