opensuse 11.4 or 12.3
Let’s say I have created and formatted a RAID1 pair with 3 partitions (swap, /, /home), and copied the data from the old system disk to the RAID.
How do I indicate that the system should boot from the RAID?
Does GRUB point to one of the physical disks /dev/sdaX, or to the RAID device, /dev/mdX? Should it use UUID or Device-by-id?
Nobody knows! 
I can say from experience that having the RAID disk ID as a boot target is not a solution. Apparently the boot loader does not know about RAID arrays at that point. I guess mdadm is not running; I rather suspected that would be the case. Would have been nice if the Boot Loader had understood that.
So. I suppose setting one of the RAID disks IDs as the target is a possibility. The Boot Loader only offers the /dev/sdX form, though, not the /dev/disk/by-id/ form.
Then there is the whole <device.map> mystery: Do I have to manually update it? Boot Loader does not seem to do anything there.