I had successfully created raid 1 array at the time of installation in CENTOS5.5. Having 4gb of swap, 250GB of root and 250MB of boot in both hdd.. When i remove sdb from motherboard and reboot the system it works fine. but if i remove sda and reboot its give grub error. WHY?? should i copy the grub details from sda to sdb or why my raid 1 is not booting from both the HDDS