Configure Oracle Enterprise Linux for an Oracle 11g install

Step by step Oracle database 11g install (Part 1)

Install Centos 6 (or any RHEL 6)

(for Unbreakable Enterprise Linux User)
as root:
If you don't have a ULN subscription you may prefer to remove up2date and access repos manually via yum instead:

yum remove up2date

add the repo in yum:

cd /etc/yum.repo.d 

wget http://public-yum.oracle.com/public-yum-ol6.repo

in /etc/yum.repos.d/public-yum-ol6.repo, the following must be with enabled=1 (the other at 0):
[ol6_latest]
[ol6_addons]
[ol6_UEK_latest]

Search for the latest Oracle software:

yum search oracle

Auto-configure your new system (users, group, pre-require packages, etc)

yum install oracle-rdbms-server-11gR2-preinstall.i686

if you have this error:

[Errno 14] Could not open/read file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle

It's because the Oracle gpg key for their repo hasn't been installed yet.

Do it and restart the install process

wget https://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 -O /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle

or

wget --no-check-certificate https://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 -O /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle

Reboot, your system is ready to have Oracle 11g installed. Di it here :)