Topic: replacing SCSI adapter

[Michael Doerner]

I would like to replace an Adaptec 2940 SCSI controller in an e-smith 4.0 system (SCSI only, no IDE HDs) with a (faster) Tekram u2w model. The existing HD supports u2 speed (80 MB).
The module for the Tekram adapter is available ("ncr53c8xx") and I thought by changing to "alias scsi_hostadapter ncr53c8xx" in /etc/conf.modules it would work but unfortunately it still wants to load the Adaptec related module "aic7xxx".

Any help what I am doing wrong or where in the startup files I would have to change?

Regards,
Michael Doerner

[Charlie Brady]

Michael Doerner wrote:

> I would like to replace an Adaptec 2940 SCSI controller in an
> e-smith 4.0 system (SCSI only, no IDE HDs) with a (faster)
> Tekram u2w model. The existing HD supports u2 speed (80 MB).
> The module for the Tekram adapter is available
> ("ncr53c8xx") and I thought by changing to
> "alias scsi_hostadapter ncr53c8xx" in
> /etc/conf.modules it would work but unfortunately it still
> wants to load the Adaptec related module "aic7xxx".
>
> Any help what I am doing wrong or where in the startup files I
> would have to change?

You need to both change /etc/conf.modules as you have done, and make a new /boot/initrd file, containing the module in a form that LILO can use at boot time.

Read the man page for mkinitrd. Make sure that you have a boot floppy made, and that it works.  Use mkbootdisk if you don't have one already.
Once you have a bootdisk which works, you can experiment with your hard drive booting arrangement.

I'd first make an initrd which contains both SCSI drivers. I think you can do this by adding a new "alias scsi_hostadapter1 ..." to /etc/conf.modules. Experiment using the -v option of mkinitrd until you get what you want. Then check that you can reboot your system that way. If it reboots OK, try switching scsi adaptors and see how that goes.

You might consider purchasing a supported copy of e-smith. You'll find that the unlimited technical support is quite useful.

Regards

Charlie

[Michael Doerner]

Charlie,
many thanks for your excellent help. You pointed me into the right direction.

As an easy way for testing, I added an "alias scsi_hostadapter1 ncr53c8xx" to /etc/conf.modules, made a boot disk, removed the Adaptec, put in the the new adapter and rebooted the machine from floppy. It detected the Tekram and loaded the ncr52c8xx module without any problem.

Unfortunately, the ncr.. module that comes with esmith (= Redhat 6.1) doesn't support 80 MB, the adapter still negotiates on 40 MB with that HD (Quantum V, 18 GB). If I put the adapter and HD into a box with a recent version of SuSE (also kernel 2.2.16!) it works on 80 MB without any adjustments. SuSE's ncr... module is a newer version.

Regards,
Michael

[Charlie Brady]

Michael Doerner wrote:

> Charlie, many thanks for your excellent help. You pointed me
> into the right direction.

I'm glad I could help.

> Unfortunately, the ncr.. module that comes with esmith (=
> Redhat 6.1) doesn't support 80 MB, the adapter still negotiates
> on 40 MB with that HD (Quantum V, 18 GB).

I doubt you'll notice the difference.

If you are really desperate for that extra little bit, you could try the kernel which ships with RedHat 7.0. You will need to upgrade the verion of RPM, and you will need to add the popt RPM.

Regards

Charlie