1.The following packages (or later versions) must be installed:

rpm -Uvh binutils-2.17.50.0.6-*.el5.x86_64.rpm
rpm -Uvh compat-libstdc++-33-3.2.3-*.x86_64.rpm
rpm -Uvh compat-libstdc++-33-3.2.3-*.i386.rpm
rpm -Uvh elfutils-libelf-0.137-*.el5.x86_64.rpm
rpm -Uvh elfutils-libelf-devel-0.137-*.el5.x86_64.rpm
rpm -Uvh glibc-common-2.5-*.x86_64.rpm
rpm -Uvh glibc-2.5-*.x86_64.rpm
rpm -Uvh glibc-2.5-*.i686.rpm
rpm -Uvh glibc-devel-2.5-*.x86_64.rpm
rpm -Uvh glibc-devel-2.5-*.i386.rpm
rpm -Uvh glibc-headers-2.5-*.x86_64.rpm
rpm -Uvh ksh-20100202-1.el5_6.6.x86_64.rpm
rpm -Uvh libaio-0.3.106-*.x86_64.rpm
rpm -Uvh libaio-0.3.106-*.i386.rpm
rpm -Uvh libaio-devel-0.3.106-*.x86_64.rpm
rpm -Uvh libaio-devel-0.3.106-*.i386.rpm
rpm -Uvh libgcc-4.1.2-*.el5.x86_64.rpm
rpm -Uvh libgcc-4.1.2-*.el5.i386.rpm
rpm -Uvh libstdc++-4.1.2-*.el5.x86_64.rpm
rpm -Uvh libstdc++-4.1.2-*.el5.i386.rpm
rpm -Uvh libstdc++-devel-4.1.2-*.el5.x86_64.rpm
rpm -Uvh make-3.81-*.el5.x86_64.rpm
rpm -Uvh gcc-4.1.2-*.el5.x86_64.rpm
rpm -Uvh gcc-c++-4.1.2-*.el5.x86_64.rpm
rpm -Uvh sysstat-7.0.2-*.el5.x86_64.rpm

rpm -Uvh unixODBC-2.2.11-*.i386.rpm
rpm -Uvh unixODBC-2.2.11-*.x86_64.rpm
rpm -Uvh unixODBC-devel-2.2.11-*.x86_64.rpm

Query installed packages, for example： rpm -q sysstat-7.*
Install essential packages, for example： rpm -Uvh sysstat-7.*

2. Create the user groups and users.

groupadd oinstall
groupadd dba
groupadd asmdba
useradd -g oinstall -G dba,asmdba oracle
passwd oracle

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

mkdir -p /u01/app/oraInventory
mkdir -p /u01/app/oracle
chown -R oracle:oinstall /u01/app
chmod -R 775 /u01/app

4. Checking resource limits for the Oracle software installation users.
Add the following lines to the "/etc/security/limits.conf" file.

oracle soft nofile 1024
oracle hard nofile 65536
oracle soft nproc 2047
oracle hard nproc 16384
oracle soft stack 10240
oracle hard stack 10240

Add the following lines to the "/etc/sysctl.conf" file:

# Oracle Settings
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 6815744
net.ipv4.ip_local_port_range = 9000 65500
net.core.rmem_default = 262144
net.core.wmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_max = 1048576
fs.aio-max-nr = 1048576

Add the following lines to the "/etc/pam.d/login" file, if it does not already exist.

session required pam_limits.so

Disable secure linux by editing the "/etc/selinux/config" file, making sure the SELINUX flag is set as follows.
Alternatively, this alteration can be done using the GUI tool (System > Administration > Security Level and Firewall).

SELINUX=disabled

5. Login as the oracle user and add the following lines at the end of the ".bash_profile" file, remembering to adjust them for your specific installation.

example1：

# Oracle Settings
ORACLE_BASE=/u01/app/oracle; export ORACLE_BASE
ORACLE_HOME=$ORACLE_BASE/product/11.2.0/dbhome_1; export ORACLE_HOME

ORACLE_SID=orcl; export ORACLE_SID

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

other env：

ORACLE_HOSTNAME
ORACLE_UNQNAME

note: To start dbconsole, the ORACLE_UNQNAME or ORACLE_SID is needed.

6. Check your hostname.

7. Check the system parameters, and install essential packages.
./runInstaller to check requirements
Check and fix parameters sets.

NOTE:
Attention to environment values, ORACLE_HOSTNAME, ORACLE_UNQNAME, ORACLE_SID. In ‘Desktop Class’ install option the default value of ORACLE_HOSTNAME is localhost.localdomain.