I suggest checking one of the online versions of TUV's installation 
guide.  Here is one example for version 5. 

http://www.linuxtopia.org/online_books/rhel5/installation_guide/rhel5_s1-x86-bootloader.html

You need to check the box for advanced boot loader options before 
hitting next.  If the drive/partition is not shown, there is a button 
for setting drive order options.

Chris



Eve V. E. Kovacs wrote:
> I am trying to install a system that has 4 disks configured as 2 RAID1 
> mirrors. One of these stores the OS and the other is intended to be a 
> data
> disk.
> My problem is that the install from the DVD wants to put the boot 
> loader on the data disk, and I don't see an option to change it to the 
> disk containing the OS. If this happens, the system doesn't boot.
>
> I have tried deleting the data disk from the list of bootable devices 
> in the BIOS and I have tried flipping the order of the disks on the 
> SATA controller. Neither of these things made a difference.
> Is there any other solution besides unplugging the data disks 
> altogether for the install and then bringing them up later?
>
> Thanks
> Eve
>
> ***************************************************************
> Eve Kovacs
> Argonne National Laboratory,
> Room F149, Bldg. 362, HEP
> 9700 S. Cass Ave.
> Argonne, IL 60439 USA
> Phone: (630)-252-6208
> Fax:   (630)-252-5047
> email: [log in to unmask]
> ***************************************************************
>