I have a second drive. I have given Qubes a portion of this drive just as a test. There is other stuff in the other partition.
I needed to add a line to grub to get some things to work and did that.
Do I just run grub2-mkconfig -o /boot/efi/EFI/qubes/grubx64.cfg and everything will be fine? Or do I need to be especially careful because I have multiple operating systems on different drives and a variety of different partitions?