However, I needed to write an install procedure for my company to install Linux and Oracle, and I wanted to get around re-compiling, because some of the installers are not that familiar with re-compiling.
IMHO, the installers who are familiar with recompiling should tutor the ones who are not.
Oracle Corporation says to recompile the kernel. You are about say, "don't recompile the kernel." In my eyes, you are about to set a very bad precedent within your company: ignore Oracle's recommendations. Running Oracle is non-trivial; anyone who is incapable of recompiling the kernel is seriously unqualified to be the system administrator for a production-grade Oracle database server.
So, the other stuff that you mentioned that you re-compile for, is it for Oracle, or just extra stuff.
Some of it is for Oracle (the shmparam.h and sem.h files per the installation guide). Other stuff is for general performance, security and additional functionality (which naturally benefits Oracle too). Remember, Red Hat has an Oracle-ready "Enterprise Edition" that has a few features (e.g., big memory, raw disk) turned on, so it order to get your Linux installation to a Oracle-happy state, you'll need to recompile anyhow.
In other words, in order to install Oracle safely...
"Safely?" I don't know how to answer that. Safe for what? Production use at Charles Schwab? The U.S. Navy? eBay? Doing the 6.916 problem sets?
...I do not need to re-compile the kernel (RH6.2).
You can install Oracle8i Release 2 (a.k.a. 8.1.6) on generic Red Hat Linux 6.1 (without having to rebuild the kernel); you're just throwing away performance and security. It is adequate for doing the 6.916 psets. I haven't tried installing Release 3 (a.k.a. 8.1.7) on a machine with a generic kernel (haven't run a generic kernel for a while).
Just one more thing, how can I check what the kernel's shmmax is actually set at (in the running kernel); i.e. is it in /proc?
It is.
cat /proc/sys/kernel/shmmax
Just remember that the Oracle Universal Installer is solely designed to allow an Oracle applications engineer to install a basic database on a machine with specific hardware/OS combinations to be shown as a small technology demonstration without painful performance issues to a potential customer. (Usually the demo hardware is much wimpier than a production machine.)
