The installer defaults to installing grub to /dev/sda even if you choose to put the root elsewhere since that is usually the disk your bios will boot from. If you want to configure your bios to boot from another disk and install grub there, then you have to tell the installer to put grub there.
** Changed in: grub-installer (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1703017 Title: grub install failed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1703017/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs