Following a tutorial I attempted to create a casper-rw drive in ext4 to make space for my program s(In xubuntu). I used Unebootin to create a 4gb persistant file on my fat32 partition. The boot was fine and I used a spare copy of another distro to delete the 4gb persistant file to make room for the significantly larger partition. Does anybody have any idea what is going wrong here? Help would be much appreciated.
It is difficult from your description to know what went wrong. It is possible to replace the file casper-rw with a partition with the label casper-rw and an ext file system (ext2, ext3 or ext4). I have done it manually, so I know that it works.
Maybe the easiest solution for you is to install mkusb and let it start from the beginning. It creates a casper-rw partition for persistence automatically.
You can decide how much of the available drive space to use for persistence. The rest (of the available drive space) will be used for a usbdata partition, available also from Windows.
See these links