John Summerfield wrote:
> Troy Dawson wrote:
>> Ken Teh wrote:
>>> I just installed a 4.5 machine and it hangs when booting at "grub
>>> loading stage 2".  Here's the strange part.  It hangs only when a SCSI
>>> disk (LVD/SE) disk is attached.  SCSI card is an Adaptec 29160.  When
>>> the  disk is removed, it rips right through the boot.  The disk is fine
>>> because I use the 4.5 install disk in rescue mode and I can see the
>>> disk, mount it, and all its data is there.  I tried with another disk
>>> and I have the exact same result.  I'm baffled!!
>>>
>>> Ken
>>
>> The odd's are that it's because the disks are getting re-ordered when 
>> you plug in and unplug the scsi disks.
>>
>> Without any disks there, grub is saying "here is my disk on (hd0,0) 
>> and away I go"  And since hd0,0 is the right disk, away it goes.
>>
>> With the other disks there grub is saying "Well, I have two disks, 
>> (hd0,0) and (hd1,0).  I'm told I need to boot off (hd0,0) and away I 
>> go"  But, in reality, your main system disk is what grub thinks is 
>> (hd1,0) and so it's booting off the wrong disk.
> 
> Ken, you can test this by getting to the grub command  line and typing 
> stuff like
> help
> root (hd0,0)
> root (hd1,0)
> find
> 
> etc etc
> 
> 

Thanks to John and Troy who responded.  Unfortunately, I was not able to 
resolve it.  I've reinstalled grub after specifying grub's root.  When I do 
this, it hangs at stage 1.5 instead of 2.  I've verified it's the correct 
root by 'finding' the stage# files. I've tried fixing the order after 
reprobing and then editing the device.map file.  I've disabled SCSI boot 
from the BIOS and verified that the BIOS boot order corresponds to the 
device.map order.  I've even tried installing the machine without the SCSI 
card so that the SL installer does not load the AIC7xxx driver.  All to no 
avail.  I'm pretty sure it's something in grub.  The system was running 
SL3.x with an IDE system disk and this external SCSI drive.  All I did was 
reinstall it with SL4.5.

Do you know if it's possible to get to the grub console at bootup but before 
it loads stage 1.5 or stage 2?  If it is reordering, then I need a "live" 
(or in this case, "dead") system to verify instead of booting succesfully 
via linux rescue, then grubbing the system.