Installing Oracle 11r2 in RHEL / CentOS (simple installation procedure with OL yum repository for learning purpose)

1. Install RHEL or CentOS . (on completion of installation dont forget to disable Firewall & SE linux)

2. Complete the prerequisites for 11G installation with Public OL yum repository as per following link.
http://www.oracle.com/technetwork/articles/servers-storage-admin/ginnydbinstallonlinux-488779.html

3. Edit /etc/hosts and add a fully qualified name for server like follows.


<IP-address>  <fully-qualified-machine-name>  <machine-name>
192.168.1.10 oratest.mydomain.com oratest


4. Set environment variable for bash shell like follows.

ORACLE_BASE=/oratest/app/oracle; export ORACLE_BASE
ORACLE_HOME=$ORACLE_BASE/product/11.2.0/dbhome_1; export ORACLE_HOME
ORACLE_SID=DBtest; export ORACLE_SID

PATH=/usr/sbin:$PATH; export PATH
PATH=$ORACLE_HOME/bin:$PATH; export PATH

LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib; export LD_LIBRARY_PATH
CLASSPATH=$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib; export CLASSPATH

5. Set the DISPLAY environment. DISPLAY=<machine-name>:0.0; export DISPLAY

6. Download RDBMS software from following link

http://www.oracle.com/technetwork/database/enterprise-edition/downloads/index.html

7. Once download complete unzip the files by unzip<filename>.zip

8. Goto OraDB11g/database (Extracted folder)

9. Make Directory for oracle software installation and give permission for same.
mkdir -p /disk1/DB
cd /disk1
chown -R oracle:oinstall /DB

10. Run the installer ./runInstaller

This will start the installation.