[NTLUG:Discuss] Kernel module woes.

[Rick Cook]

On Tuesday 23 July 2002 13:16, Scott Denlinger wrote:
> I recently set up a Debian Woody box using the 2.4 kernel boot flavor
> specified in the setup disks. I have a QIC tape drive in this, so I
> thought I would install Ftape, and compile and install it as a kernel
> module. It appears that in order to do this, it was necessary for me
> to recompile my kernel, so I did that, and now there are a lot of
> modules that don't get loaded when I boot. Here is the process I went
> through.
>
> 1. I installed the kernel sources via dselect, so the sources are in
> /usr/src/kernel-source-2.4.18
>
> 2. I used 'make xconfig' to create a .config file. In the process of
> doing that, I realized I could just configure ftape support in the
> kernel without messing with ftape as a standalone program, so that's
> what I did.

The recommendation to use an old configuration file from /boot was a 
good one. It is entirely possible to compile a Linux kernel and 
associated set of modules that do not do what you want and in all 
probability will work significantly differently from the kernel you are 
replacing.

>
> 3. I then used Debian's kernel-package tool to create a .deb file.
> Specifically, I used 'make-kpkg kernel_image', which resulted in a
> .deb file. I installed this using 'dpkg -i <file>.deb
>

This process does the equivalent of make modules;make modules-install 
as it creates the kernel-image .deb. Unfortunately, you don't get much 
feedback about whether or not you have configured a complete and 
complementary set of kernel features and modules features for your 
particular set of hardware.

> 4. I let this go ahead and make modifications to lilo, and rebooted
>
> Lilo successfully booted up the new kernel, but now there are a lot
> of messages about modprobe not being able to find any modules. The
> result of this is that I am not connected to the net on this box,
> since the modules for my NIC cards aren't loaded.
>

Debian can't run "depmod -a" for the new set of modules until after you 
reboot. I sometimes have to run it myself after rebooting using the new 
kernel. You can then re-run the appropriate scripts in /etc/init.d to 
start up the module dependent services (or take the easy way out and 
re-boot).

> What step did I miss in the above process? Doesn't the kernel_image
> which the make-kpkg creates also create and install the modules?
>

Yes, as I said above, the make-kpkg process creates the modules and 
includes them in the kernel-image package.


> Obviously I'm in over my head here, but I suspect there is a simple
> solution to my problem. Thanks in advance for any tips.
>

Debian defines the set of modules to load at system boot in the file 
/etc/modules.


Rick