ubuntu@ubuntu:~$ sudo grub-install --boot-directory=/media/ubuntu/aa9a8b40-8489-4309-992e-5ffe0533bc41/boot /dev/sda
/usr/sbin/grub-bios-setup: warning: Sector 32 is already in use by the program `FlexNet'; avoiding it.  This software may cause boot or other problems in future.  Please ask its authors not to store data in the boot track.
Installation finished. No error reported.