learn-oracle-RAC: Step by Step installation oracle 12c database on Linux 6 (centos)

Assumptions :

You have a some flavor of Linux operating system installed (I have used centos 6 in this example).
If you cant afford a separate machine you can use Virtual box or stemware software to visualize your desktop or laptop.
Assuming that you have downloaded oracle 12 software onto linux machine. If not you can download from this link Software-Download
You have full/required privileges on you Linux host.

Oracle Installation Prerequisites

In order to perform the installtion of oracle 12c software on Linux box you need to perform some pre-reqs, which can be done automatically or through manual updates.Please follow below instructions.

Automatic Setup

If you plan to use the "oracle-rdbms-server-12cR1-preinstall" package to perform all your prerequisite setup, issue the following command.

# yum install oracle-rdbms-server-12cR1-preinstall -y

It will be a good option to to do an update.

# yum update

************* ***********

MANUAL SETUP

************* ***********

If you have not used the "oracle-rdbms-server-12cR1-preinstall" package to perform all prerequisites, you will need to manually perform the following setup tasks.

Add or amend the following lines in the "/etc/sysctl.conf" file.

fs.file-max = 6815744

kernel.sem = 250 32000 100 128

kernel.shmmni = 4096

kernel.shmall = 1073741824

kernel.shmmax = 4398046511104

net.core.rmem_default = 262144

net.core.rmem_max = 4194304

net.core.wmem_default = 262144

net.core.wmem_max = 1048576

fs.aio-max-nr = 1048576

net.ipv4.ip_local_port_range = 9000 65500

Run the following command to change the current kernel parameters.

/sbin/sysctl -p

Add the following lines to the "/etc/security/limits.conf" file.

oracle soft nofile 1024

oracle hard nofile 65536

oracle soft nproc 16384

oracle hard nproc 16384

oracle soft stack 10240

oracle hard stack 32768

MANUALLY INSTALL PACKAGES FROM INTERNET OR FROM CD DRIVE(below is to install from INTERNET) :

# From Public Yum or ULN

Yum install binutils, compat-libcap1, compat-libstdc++-33, compat-libstdc++-33.i686, gcc, gcc-c++, glibc, glibc.i686, glibc-devel, glibc-devel.i686, ksh, libgcc, libgcc.i686, libstdc++, libstdc++.i686, libstdc++-devel, libstdc++-devel.i686, libaio, libaio.i686, libaio-devel, libaio-devel.i686, libXext, libXext.i686, libXtst, libXtst.i686, libX11, libX11.i686, libXau, libXau.i686, libxcb, libxcb.i686, libXi, libXi.i686, make, sysstat, unixODBC, unixODBC-devel

Create the new groups and users as per your requirement. For my case just to keep it simple lets use 3 groups & oracle user.

groupadd -g 54321 oinstall

groupadd -g 54322 dba

groupadd -g 54323 oper

useradd -u 54321 -g oinstall -G dba,oper oracle.

Set SELINUX to permissive or diable it if this is test env.

Set secure Linux to permissive by editing the "/etc/selinux/config" file, making sure the SELINUX flag is set as follows.

SELINUX=permissive

Create the directories in which the Oracle software will be installed.

mkdir -p /u01/app/oracle/product/12.1/db_1

chown -R oracle:oinstall /u01

chmod -R 775 /u01

LOGIN AS ORACLE USER AND

Add the following lines at the end of the "/home/oracle/.bash_profile" file.

# Oracle Settings

export TMP=/tmp

export TMPDIR=$TMP

export ORACLE_HOSTNAME=ol6-121.localdomain

export ORACLE_UNQNAME=orcl

export ORACLE_BASE=/u01/app/oracle

export ORACLE_HOME=$ORACLE_BASE/product/12.1/db_1

export ORACLE_SID=orcl

export PATH=/usr/sbin:$PATH

export PATH=$ORACLE_HOME/bin:$PATH

export LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib

export CLASSPATH=$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib

Change your directory to location where you have downloaded oracle software.

Start the Oracle Universal Installer (OUI) by issuing the following command in the database directory.

./runInstaller

I don't want any update to uncheck to receive updates.

Lets create a server class.

To keep this simple I am going to select typical installation.

Make sure you have selected the home path correct.

After This step you will be notified if you have any pre-req failures. Make sure you have cleared them all. Missing ksh package can be ignored as this is a known bug. Oracle is expecting a specific version of ksh & i have a latest pkg. Assuming that you have all cleared up.

Now select install.

Now you will be prompted to execute shell scripts before the installation of software is complete. I have missed that prompt screen but it will ask you to execute below 2 shell scripts as root user. see below screen