Comment 9 for bug 704763

The problem with the installer at the moment is that it blindly tries to install GRUB to the first disk in GRUB's device map, regardless of if it can or not (apart from the special removable device code). This causes problems when /dev/sda is a secondary disk that isn't configured at the time of installation, and so because it contains no MBR GRUB fails to install on it. I can see why installing to a drive that is different to the one /boot exists on is beneficial with multiple OSes, but to be honest when one selects 'erase disk and install Ubuntu' they likely do not have or care about any other operating systems on other drives.

Even if another operating system exists on another drive, with this patch GRUB will be installed to the 'secondary' drive, and so to start using it one must simply change the boot order in the BIOS/UEFI. In addition, perhaps the user does not want to overwrite the existing bootloader, say, if GRUB is being managed by a different distribution on the same system. But I just think that if one has another OS installed on a system, they'd probably use the manual partitioning selection which allows them to set the bootloader location manually, rather than the 'automate everything, erase disk and install' option.