Forum OpenACS Q&A: Re: Re-installing Oracle
echo 2147483648 > /proc/sys/kernel/shmmaxinto one of the startup files (I forgot which one, I have wiped the box since then).
The glibc patches are important as well, IIRC I installed them before installing Oracle. Unfortunately I have nothing to offer as help regarding the root.sh issues, I haven't encountered any. If I get to the point of installing Oracle on a new Linux box I'll try to take notes and post them here. Don't hold your breath however, I'm changing job in the next weeks so my time allocation will get... interesting.