[CentOS] Adding a kernel module to the ISO/installer initrd?

[Tim Nelson]

----- "Tim Nelson" <tnelson at rockbochs.com> wrote:
> Greetings list!
> 
> Because of the sheer number of box (re)installations we do that have a
> CentOS base, I've converted our provisioning process to PXE. However,
> I've found that an alarming number of motherboards are coming with the
> Realtek RTL8168 ethernet controller onboard. When the system boots, it
> cannot find an ethernet controller and the installer process hangs.
> 
> I made a new initrd from a running system that was installed via CD
> and had the kernel module installed afterwards. However, when using
> the new initrd to PXE boot a new box, it dies saying something about
> not being able to use/find /dev. The original initrd from the ISO is
> 5.1MB whereas the initrd I built from the working system is only
> 2.4MB. I have a feeling that the initrd I built (using mkinitrd -v
> --with=r8168 <path to output initrd> <kernel version>) does not
> include modules required by the installer.
> 
> So, my question is this: is there a way to (1) create an initrd with
> ALL available modules or at the very least, (2) take the original ISO
> initrd and simply add the module I need? This initrd will need to work
> with all of the other hardware I support and should not be specialized
> for this single motherboard if possible.
> 
> I've been up and down Google/CentOS Wiki/etc and cannot seem to find a
> valid way of doing either of the above.
> 
> Suggestions, ideas, help?
> 

Surely someone has rebuilt the initrd for the installer ISO? I recall seeing something on the list about it previously in regards to storage controllers but I cannot seem to find it now...

Is there somewhere I can look to see the original mkinitrd command used to build the initrd on the ISO? I could then ensure I have all of the modules specified there along with my additional module.

--Tim