Misleading device mapping when installing Grub on second disk.

[Stefano Giorgi]

I have first hard disk /dev/hda with WinXP and the second disk /dev/hdb 
with linux. I booted the system with floppy, and now I am trying to 
install grub ont the MBR of disk /dev/hdb.
Looking at /boot/grub/device.map I first I tried with a grub.conf like this:
------------------------------------------
title Red Hat Linux (2.4.18-14)
       root (hd1,0)
       kernel /boot/vmlinuz-2.4.18-14 ro root=/dev/hdb1 hdd=ide-scsi
       initrd /boot/initrd-2.4.18-14.img
title XP
       rootnoverify (hd0,0)
       chainloader +1
       makeactive
-------------------------
and installed grub with grub-install /dev/hdb but it didn' work.
It seems that if I install grub on disk /dev/hdb this disk will be 
recognized by grub as the first disk, and reference it as disk hd0, not 
hd1. To make it work I had to change it to:
title Red Hat Linux (2.4.18-14)
       root (hd0,0)
       kernel /boot/vmlinuz-2.4.18-14 ro root=/dev/hdb1 hdd=ide-scsi
       initrd /boot/initrd-2.4.18-14.img
title XP
       rootnoverify (hd1,0)
       chainloader +1
       makeactive
-----------------------------------------

I don't know if it's a bug or a feature, but I believe that it's not 
very well documented if it's a feature, and could be quite misleading.
Ciao
Stefano