Just watch out, sometimes grub-install doesn't do what you would expect. e.g. sometimes an install on sdb can depend on sda.

e.g. recently I wanted to replace my disks with bigger disks, so I ran:

grub-install /dev/sda   # yes, this was redundant

grub-install /dev/sdb

Then removed sda, replaced with new disk, and attempted to boot from sdb.

For some reason, grub insisted on loading itself from sda, not sdb, which of course didn't work, and as I result I only got the restricted rescue mode grub command line. Which I am totally unfamiliar with, and I couldn't do a Google search easily without the server which I had just taken offline. Fortunately I booted a rescue system via CD (which I had prepared earlier just in case) and fixed it.

(This was with a Debian wheezy system)

I am not sure of the boot sequence used by grub2, so not sure exactly what went wrong here. Maybe it was trying to load files from /boot which is software raid1 on both disks.