I want to create partitions so that i can use my external harddrive to move between my mac and my ubuntu laptop. I dled gparted and created a fat32 partition and an ext4 partition but the mac disk utility wouldn't recognize that those existed nor would it show me the unallocated space so that i could create a mac journaled partition without messing up the other partitions. So I tried to start by creating a partition in the mac. Even though it was a 500gb drive and id only allocated 100gb to the mac journaled partition, when i went back to gparted, no unallocated data showed up. What should i do?