end of first paragraph advises that one should install grub to ubuntu root partition. This is not currently correct. should be changed or deleted as default grub install location is what is actually required there. I tried installing using docs and it didn't work. after attempting to sync partition tables and used gdisk to rewrite MBR, still couldn't boot linux. reinstalled ubuntu over previous attempt and now i can boot. i assume that the auto reinstall option did not honor my previous grub install location setting; if it does honor previous grub install location then i am in error and the docs might be correct.