Grub - dual boot fails on sdb
 

Hi:

I have a Sun V20z with two SCSI drives, sda and sdb (not mirrors) with the following RH distributions:

disk release boot partition root partition SCSI LUN
sda 9.0 sda1 sda5 0
sdb 7.3 sdb1 sdb5 1

I can succesfully boot 9.0 from sda using the following grub.conf entry:

root (hd0,0)
kernel /vmlinuz-2.4.20-8smp ro root=LABEL=/
initrd /initrd-2.4.20-8smp.img

However, with both drives installed, I cannot boot 7.3 from sdb; I get the standard kernel panic. I suspect the root partition is not getting mounted properly. My grub stanza for sdb is:

root (hd1,0)
kernel /vmlinuz-2.4.18-3 ro root=/dev/sdb5
initrd /initrd-2.4.18-3.img

If I remove the first drive, the one containing RH 9.0 and change the appropriate references in the stanza to sda, then I'm able to successfully
boot 7.3 (even though the LUN is still 1, the drive maps to sda). As a result, I know:

o my 7.3 OS is OK,
o my device driver for the disk is not the issue (by the way, both disks
are the same), and
o my boot and root partitions are good.

My device map on each of the disks is:

(fd0) /dev/fd0
(hd0) /dev/sda
(hd1) /dev/sdb

I'm new to grub (in my case, version 0.93). I'm thinking either a problem with my grub configuration or a BIOS issue. If anyone has any ideas, I'd appreciate it.

Michael Homa