If you see the following similar issue when installing grub on a replacement drive
root@server:~# grub-install /dev/sdc /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> </bug-grub@gnu.org>
Run the following
1. mv /boot/grub/device.map /boot/grub/device.map.old 2. grub-mkdevicemap 3. update-grub2 4. grub-install /dev/sdX (run for both drives)