Rather than juggling partitions, consider using a btrfs. I typically have four or five different *buntus in separate subvolumes.
Also, I suggest also installing grub to its own subvolume (or partition), and manually editing grub.cfg there, using the vmlinuz and initrd.img symbolic links so that the entries don't have to be updated frequently. I suggest using partition labels in /etc/fstab and grub.cfg rather than UUIDs; they're much more readable. If multiple distros have grub installed to update the boot, each tries to control the boot and confusion is the result. Consider switching to the grub package that does not automatically update the boot, at least on all but one install, or none as in my suggestion above. -- Regards, John Little
