The fastest way to configure an Oracle Enterprise Linux server for an Oracle database installation is to run the Oracle Validated RPM.
A YUM server provides a repository for RPM packages and their associated metadata. This makes installing the packages and their dependencies straightforward. Oracle provides a public YUM server at http://public-yum.oracle.com, but its server provides only the packages you have already downloaded on the installation media. Subscribers to the Unbreakable Linux Network can access additional security updates and patches on top of the content available on the public YUM server. If you do not have access to the Unbreakable Linux Network or you do not wish to use the public YUM server, it is a simple enough process to configure your own from the installation media.
To Configure YUM using Proxy server
[root@coltdb01 ~]# cd /etc/yum.repos.d/
[root@coltdb01 yum.repos.d]# http_proxy=http://10.XX.XX.10:80
[root@coltdb01 yum.repos.d]# export http_proxy
For RHEL 5
[root@coltdb01 yum.repos.d]# wget http://public-yum.oracle.com/public-yum-el5.repo
--2012-10-25 16:25:53-- http://public-yum.oracle.com/public-yum-el5.repo
Connecting to 10.91.118.10:80... connected.
Proxy request sent, awaiting response... 200 OK
Length: 3974 (3.9K) [text/plain]
Saving to: `public-yum-el5.repo'
100%[===========================================================================================================================================================>] 3,974 --.-K/s in 0.004s
2012-10-25 16:25:53 (1.04 MB/s) - `public-yum-el5.repo' saved [3974/3974]
[root@coltdb01 yum.repos.d]# yum install oracle-validated
For RHEL 6
[root@linux yum.repos.d]# wget http://public-yum.oracle.com/public-yum-ol6.repo
[root@linux yum.repos.d]# yum install oracle-rdbms-server-11gR2-preinstall
Once the Oracle Validated RPM installation completes, all the RPM packages and system configuration steps required for an Oracle Database 11g Release 2 RAC installation have also been completed. For example, the required user and groups have been created, and the necessary kernel parameters have been set.You can find the installed packages listed in /var/log/yum.log