> Is there a way to specify that the boot loader will be installed to a
> partition, i.e. /dev/sda6 instead of to /dev/sda during Qubes 4.0
> install? I couldn't figure it out in the install menu, the only thing I
> can select is not to install the boot loader to /dev/sda—which would be
> fine, if I can then do it later.
I think you are talking about manual partitioning here? That's the only
way I know too.
Modifying your steps a bit might make it easier:
— install Qubes to sda6 without the boot loader
— boot your primary Linux OS (the one that originally set up GRUB on your
HDD)
— run grub-mkconfig and/or edit grub.cfg manually to add entry for Qubes