need some background information

Hi,

This is a question that Tom would probably be in the best position to 
answer, but if anyone else has any input, I'd appreciate that too.

I have a Compaq ProLiant 2500R which I recently upgraded from dual Pentium 
Pros to dual Pentium II processors.  After the upgrade, my Linux 
installation will no longer work; the kernel panics because it cannot mount 
the root file system.  The details of my system are:

Adaptec AHA-2940 controller with a 4.3 GB drive.  This is the boot drive, 
and also the /tmp partition.

Compaq embedded SCSI controller (NCR53C875) with one 4.3 GB and four 9.1 GB 
hot-plug SCSI drives.  The 4.3 drive is home to /, /usr, /var, and /usr/src.

Compaq SMART-2/P RAID controller with no drives attached yet.

1 GB RAM

So why am I writing to this list?  Well, I have used Tom's disk to boot 
this system in the past, so I naturally thought that I'd give it a try when 
I had problems.  I got the latest version (2.0.103), and it boots fine, but 
will not recognize the embedded Compaq controller, so I have no access to 
/, /usr, etc.  I can access all partitions on the 4.3 GB drive attached to 
the Adaptec controller.  After some searching, I found an older version of 
Tom's disk (1.7.361), and tried it.  The old version has no problems with 
any of the controllers, I can mount every partition, chroot, and try to 
rebuild my kernel.

But that is the main problem.  Regardless of the options I choose, I cannot 
get the kernel to work with the controllers correctly.  The AIC-7xxx driver 
has problems; it tries to probe every device ID, but fails (even on the one 
drive that does exist).  The ncr53c875 (or sym53c875) driver does not 
complain, but I still get a kernel panic indicating that it can't mount the 
root fs on 08:11 (which would be the correct major and minor numbers for 
the root partition).  I have also tried to use the normal I/O option 
instead of memory-mapped I/O when building the kernel, but no luck.

So Tom, do you have any idea what might have changed between version 
1.7.361 and 2.0.103?  The kernel I am using is 2.4.16.  I am not using any 
distribution, but have compiled all programs on this system from the 
sources.  It used to work just fine before I switched to the dual 
Pentium-II board.  Since I can work with the system using the 1.7.361 
version of tomsrtbt, I know that the hardware is supported by Linux in some 
way.  I just need help finding out what I must do to get the kernel to 
recognize the SCSI controllers correctly.

TIA,
Carsten
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                             Carsten P. Gehrke
                      mailto:[email protected]
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