I went from a 250MB to 73GB. I had to install everything from scratch. I ran into that issue. I think I kept it at 4G partitions anyway since everything is so small on the Amiga. There is a super file system or something like that on Aminet that is suppose to handle huge drives but I didn't have any luck with that. But the Native 3.9 FastFileSystem worked well. Also, with big drives, it takes away ram as well.