[root@MagicLinux RPMS]# grub-install --help
Usage: grub-install [OPTION] install_device
Install GRUB on your drive.
-h, --help print this message and exit
-v, --version print the version information and exit
--root-directory=DIR install GRUB images under the directory DIR
instead of the root directory
--grub-shell=FILE use FILE as the grub shell
--no-floppy do not probe any floppy drive
--force-lba force GRUB to use LBA mode even for a buggy
BIOS
--recheck probe a device map even if it already exists
INSTALL_DEVICE can be a GRUB device name or a system device filename.