This is the part that I think is the problem:
Raid10 Hardware raid (4x SAS drives)
Does the kernel (or the initrd) file have the module for your raid controller.
Could you indicate what RAID controller card you have?
Can you boot up to a CD or DVD live distro? If so, and it has the kernel module needed you can modprobe the driver to gain access to the raid array.
There is a grub raid howto on the
www.tldp.org web site.