[CentOS] Partitionable Raid

Hi,

After reading the tutorial at
http://wiki.centos.org/HowTos/Install_On_Partitionable_RAID1 I have the
following question:

What should I put instead of
splashimage=(hd0,0)/grub/splash.xpm.gz

and

        root (hd0,0)

on /etc/grub.conf? Should I leave those lines untouched? If so, how would
grub know where to boot from if /dev/sda fails?

Or I would need to swap the drives in order to boot properly and then put a
new one as /dev/sdb and then add it to the array?

Thanks in advance for all the help.

Best regards,

Eugenio Pacheco