3.4 GRUB Device Nomenclature
In both GRUB versions, the first hard drive is denoted as hd0, the second as hd1, etc. However, in version 1, partitions start counting from 0 and in version 2 from 1:
sda1 is (hd0,1) in GRUB 2 but (hd0,0) in GRUB 1.
sdc4 is (hd3,4) in GRUB 2 but (hd3,3) in GRUB 1.
Wouldn't sdc by hd2?