Hi

Running OpenSUSE as a main distro, with GRUB on the MBR. (root at hda5)

Had 2 unused partitions, onto which I have installed /home and root (at hda6) of Arch Linux (earlier Debian). When installing, I put the GRUB to the root partition (hda6).

To the openSUSE grub at MBR, I have added a new chainloader option, which, when selected, takes me to the Arch Linux GRUB at hda6.

Now, I haven't been able to actually boot Arch, nor Debian earlier with this same setting. Neither from the Arch, nor the openSUSE GRUB (even by editing the GRUBS to point to the correct kernel and initrd's.

Menu.lst of the Arch GRUB:
-------------------------------
# (0) Arch Linux
title Arch Linux
root DEVICE NOT FOUND
kernel /boot/vmlinuz26 root=/dev/disk/by-uuid/4652b23e-b2a4-4a44-82cb-be9709c4de7f ro
initrd /boot/kernel26.img
--------------------------------

/boot of Arch:
--------------------------------
config-2.6.26-1-amd64
grub
initrd.img-2.6.26-1-amd64
System.map-2.6.26-1-amd64
vmlinuz-2.6.26-1-amd64
--------------------

Menu.lst of SUSE:
--------------------------------------
title openSUSE 11.0 - 2.6.25.18-0.2
root (hd1,4)
kernel /boot/vmlinuz-2.6.25.18-0.2-default root=/dev/disk/by-id/scsi-SATA_IC35L020AVER07-_SVPTVF08599-part5 resume=/dev/sda1 splash=silent showopts vga=0x317
initrd /boot/initrd-2.6.25.18-0.2-default

title Arch chainloader
rootnoverify (hd1,4)
chainloader (hd1,5)+1

title Arch direct
root (hd1,4)
kernel /boot/vmlinuz root=/dev/disk/by-id/scsi-SATA_IC35L020AVER07-_SVPTVF08599-part6
initrd /boot/kernel26.img
-------------------------------------

Note the "DEVICE NOT FOUND" in GRUB. I have edited it to point to correct hd(1,5). Note SUSE is hd(1,4)

Also note the last line of SUSE GRUB "Arch direct". I have added it using YAST, and while pointing it to the correct device (hda6 = hd(1,6)), Yast assigned it hd(1,4), and even if I edit it manually in grub to be hd(1,6), I can't boot to Arch.

The GRUBs do not give consistent error messages either. Sometimes it's "file not found", sometimes something else.

I am totally puzzled by this. Suggestions greatly appreciated..!

Do you have several HD's?

Post the output of fdisk -lu or maybe a problem with device.map

fdisk -lu

Disk /dev/sda: 20.5 GB, 20576747520 bytes
255 heads, 63 sectors/track, 2501 cylinders, total 40188960 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x3cc40730

Device Boot Start End Blocks Id System
/dev/sda1 * 63 1028159 514048+ 82 Linux swap / Solaris
/dev/sda2 1028160 40178564 19575202+ 5 Extended
/dev/sda5 1028223 15454529 7213153+ 83 Linux
/dev/sda6 15454593 25768259 5156833+ 83 Linux
/dev/sda7 25768323 38074049 6152863+ 83 Linux
/dev/sda8 38074113 40178564 1052226 83 Linux

Disk /dev/sdb: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x4eddbdf2

Device Boot Start End Blocks Id System
/dev/sdb1 * 63 124086059 62042998+ 83 Linux
/dev/sdb2 124086060 156296384 16105162+ 5 Extended
/dev/sdb5 124086123 156296384 16105131 83 Linux

Disk /dev/sdc: 262 MB, 262144000 bytes
16 heads, 32 sectors/track, 1000 cylinders, total 512000 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x91f72d24

Device Boot Start End Blocks Id System
/dev/sdc1 * 32 511999 255984 6 FAT16

hd(1,5) is a grub notation : stands for : 6th partition on second hd
(Counting in grub starts at 0 !

hda is mostly hd(0
But this depends on your device.map

post your device.map

device.map says

(hd1) /dev/sda
(hd0) /dev/sdb

I has wondering a bit earlier why suse is on hd(1,4) since it's the first hd.

Yes, I'm aware of this. I think I have tried the correct options in any case.

device(s).map determines the hd# value (in theory). A little odd that it's out of order though.

Any reason you have (hd1,4) for rootnoverify and (hd1,5) for chainloader? Shouldn't they match?

I think I have found the source of confusion..

The device.map in the second (Arch) GRUB is

(hd0) /dev/hda
(hd1) /dev/hdd

So the device maps of the two grubs don't match. I can't boot right now to do experiments but will try later today if it leads to a solution.

Shadow7: I don't know - perhaps they should!

You could always use the command mode of grub. "c" instead of selecting a menu option. Type in the menu.lst entry manually. It has help and tab completion so you should be able to notice what grub is trying to do, versus what you have in your configuration. And adjust accordingly. Or not.