THIS DOESN'T WORK: grub> root (hd0,2) grub> setup (hd0,2) Error 17: cannot mount selected partition Without mirror (raid1) it works. With raid1 it works only on first partition. Can you explain me why?

I've found strange problem in new Fedora 15. I suppose it should work. It's maybe fdisk or grub problem. Normaly I have this (working) multiboot solution on my home PC: On first small (100MB) partition are grub1 files only with this config (grub is installed to MBR): --- cut --- title Fedora 15   root (hd0,2)   chainloader +1 title Fedora 14   root (hd0,4)   chainloader +1 title Ubuntu   root (hd0,5)   chainloader +1 --- cut --- Grub of linux distributions is installed into their partitions I want make the same on mirrored environment 2 HD in mirror (raid1):        size    id      OS/SW           FS 1. part 200MB   fd      grub            ext4 2. part 8GB     82      SWAP            swap 3. part 10 GB   fd      fedora 15       ext4 4. part extended 5. part 10 GB   fd      fedora 14       ext4 6. part 10 GB   fd      ubuntu          ext4 ... last part rest. of disk - LVM I've installed Fedora 15 on /dev/md0 (/dev/sda1,/dev/sdb1)          /boot /dev/md1 (/dev/sda3,/dev/sdb3)          / grub was in MBR and everything worked. THIS WORKS: grub> root (hd0,0) grub> setup (hd0) When I want put grub of Fedora 15 to start of /dev/sda3 grub is complaining: THIS DOESN'T WORK: grub> root (hd0,2) grub> setup (hd0,2) Error 17: cannot mount selected partition Without mirror (raid1) it works. With raid1 it works only on first partition. Can you explain me why?