after software RAID in linux ,won't boot from second SCSI

Hi
can anybody help me regarding software RAID in LINUX
1) we configure software RAID using linux FC3
2) system boot successfully using both hard disk
3) we want to boot using second hard disk if first harddisk fail
4) When the machine reboots back into RHEL, it will have working software RAID, however the boot loader will only be installed on the first disk (/dev/hda). To install this on the second disk (/dev/hdc), we need to run grub.
5) we want to change in grub.conf
6)grub> device (hd0) /dev/hdc
grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0xfd
grub>

7) after this we want get any message and even when we try to boot from seconf hard disk , boot screen blank .
please anybody help me

regards
anuradha

after software RAID in linux ,won't boot from second SCSI

From what you said, your first hard drive is named hda and the second hdc. This means they are not SCSI, if they were scsi they should be named sda and sdb.

6)grub> device (hd0) /dev/hdc
grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0xfd
grub>

7) after this we want get any message and even when we try to boot from second hard disk , boot screen blank .

You should also execute "setup (hd0)" after what you typed, in order to have grub install to the MBR of the hdc hard disk.

So it should be like this:
[code:1]grub> device (hd0) /dev/hdc
grub> root (hd0,0)
Filesystem type is ext2fs, partition type 0xfd
grub> setup (hd0)[/code:1]

I hope that helps.

boot loder installed on both hard disk successfully
but when remove any one hard disk and try to boot using second hard disk we got error as follow
[code:1]md: pers->run() failed..........
md: pers->run() failed..........
md: pers->run() failed..........
EXT3-fs: unable to red superblock
mount: error 22 mounting ext3
mount: error 2 mounting none
switchroot: mount failed: 22
umount /initrd/dev failed: 2
kernel panic - not syncing: Attempted to kill init![/code:1]

may i wrong anywhere

please reply
thank you
regards
Anuradha

Hmm, are you sure you have set up Raid level 1 (mirroring)?

Is it possible that you post the result of [code:1]mdadm --detail --scan[/code:1]

as well as your /etc/fstab file?

Thank you