bash-4.2# grub-install /dev/sdb1          
/usr/sbin/grub-probe: error: no such disk.
Auto-detection of a filesystem of /dev/md0 failed.
Please report this together with the output of "/usr/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub" to <bug-grub@gnu.org>
bash-4.2# grub-install -v
grub-install (GRUB) 1.99~rc1
bash-4.2#