hd0,1 and /dev/sda1

[horseriver]

hi:
  
  Boot with grub failed with no finding /dev/sda1.
  kernel = (hd0,0)/vmlinuz    root=/dev/sda1
  when booting ,kernel can be rightly loaded from hard disk
  but,when mounting root , it can nt find /dev/sda1 .

  what about is the reason?

thanks!