I read that due to an error at casper scripts, Ubuntu 15.10+ assumes at boot time that the first partition is the persistence partition and the second one is the root.
So this drops you to initramfs shell before boot if you try to follow the guides, creating a second partition with casper-rw label and delete casper-rw file due to file-size constraints of FAT32.
My question is, how can I create a persistence partition on the usb-stick (which is pretty fast) and boot Ubuntu 16.04 without dropped to initramfs shell?