Building a custom kernel does not have to be terribly difficult. There
are different schools of thought. One is to take the present working kernel's
config file and use it to build a new kernel. Doing this can achieve the
desired result, but you won't learn much (if anything) about kernel building.
You'll also still have a very large kernel.
When I first starting using GNU/Linux, it was amazing to me that I could
actually rebuild my kernel, excluding drivers (modules) for hardware that is
not in my computer. That's one of the things that makes Windows "easy to use"
for a lot of PCs, and has allowed it to dominate the desktop market. There are
drivers included for hundreds, if not thousands, of pieces of hardware.
Building, compiling, and installing a custom kernel takes reading and learning,
and patience. Today it seems there is a dearth of people willing to read, even
man pages or online HOW-TOs, in order to learn.
These are some resources that will help you learn how to build a custom kernel:
Start by downloading the latest source from Kernel.org (2.6.24.3 as of this post).
Unpack the source and open ./linux-2.6.x.y/README -- and do just that. The book
Linux Kernel in a Nutshell will educate you beyond measure. It is available in
both PDF and DocBook formats. Since I haven't yet learned about DocBook, I d/led
the tarball of the pdf files and used pdftk to make one file of them.
Follow the guide above and Linus' advice in the README file. For the actual install
you have to be root (and can even use sudo), but none of the normal build should
require that. Don't take the name of root in vain.
You might not get a bootable kernel the first time, which is why you should follow
the advice in my guide about leaving your old kernel in place.
Another thing I do is add append="panic=15" to /etc/lilo.conf so that if I mess up and
get a kernel panic, the system will reboot itself after 15 seconds. If you think you'll
need more time to read the onscreen output, increase the time.
Building a custom kernel teaches one a lot about their system. There is so much
more included in the kernel than simple hardware support.
EDIT: Also, for your problem, make sure that /etc/rc.d/rc.scanluns is
executable. If not, issue "chmod +x /etc/rc.d/rc.scanluns" as root.