Required packages (for 64-Bit systems)

# rpm -q compat-libstdc++-33.x86_64 binutils elfutils-libelf elfutils-libelf-devel
# rpm -q glibc glibc-common glibc-devel glibc-headers gcc gcc-c++ libaio-devel
# rpm -q libaio libgcc libstdc++ make sysstat unixODBC unixODBC-devel

If anything is missing install it using:

# yum install compat-libstdc++-33.x86_64 binutils elfutils-libelf elfutils-libelf-devel
# yum install glibc glibc-common glibc-devel glibc-headers gcc gcc-c++ libaio-devel
# yum install libaio libgcc libstdc++ make sysstat unixODBC unixODBC-devel

Required packages (for 32-Bit systems)

# rpm -q compat-libstdc++-33.i686 binutils elfutils-libelf elfutils-libelf-devel
# rpm -q glibc glibc-common glibc-devel glibc-headers gcc gcc-c++ libaio-devel
# rpm -q libaio libgcc libstdc++ make sysstat unixODBC unixODBC-devel

If anything is missing install it using:

# yum install compat-libstdc++-33.i686 binutils elfutils-libelf elfutils-libelf-devel
# yum install glibc glibc-common glibc-devel glibc-headers gcc gcc-c++ libaio-devel
# yum install libaio libgcc libstdc++ make sysstat unixODBC unixODBC-devel

You will need unzip or a similar programm later on

# yum install unzip

Create Oracle's user and groups

# groupadd oinstall
# groupadd dba

# useradd -m -g oinstall -G dba -s /bin/bash oracle
# passwd oracle

kernel.sem

# sysctl -a | grep kernel.sem

should be ≥ than:

kernel.sem = 250   32000   100   128

kernel.shm

# sysctl -a | grep kernel.shm

should be ≥ than:

kernel.shmmax = 536870912
kernel.shmmni = 4096
kernel.shmall = 2097152

file-max

# sysctl -a | grep file-max

should be ≥ than:

fs.file-max = 6815744

ip_local_port_range

# sysctl -a | grep ip_local_port_range

minimal value should be ≤ 9000 and maximum value should be ≥ 65500, see example below:

net.ipv4.ip_local_port_range = 9000   65500

rmem_default

# sysctl -a | grep rmem_default

should be ≥ than:

net.core.rmem_default = 262144

rmen_max

# sysctl -a | grep rmem_max

should be ≥ than:

net.core.rmem_max = 4194304

wmem_default

# sysctl -a | grep wmem_default

should be ≥ than:

net.core.wmem_default = 262144

wmem_max

# sysctl -a | grep wmem_max

should be ≥ than:

net.core.wmem_max = 1048576

aio-max-nr

# sysctl -a | grep aio-max-nr

should be ≥ than:

fs.aio-max-nr = 1048576

All required parameters:

kernel.sem = 250 32000 100 128
kernel.shmmax = 536870912
kernel.shmmni = 4096
kernel.shmall = 2097152
fs.file-max = 6815744
net.ipv4.ip_local_port_range = 9000 65500
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

Apply the changes:

# sysctl -p

Edit /etc/security/limits.conf

# vi /etc/security/limits.conf

Add the following:

oracle soft nproc  2048
oracle hard nproc  16384
oracle soft nofile 1024
oracle hard nofile 65536

Edit /etc/pam.d/login

# vi /etc/pam.d/login

For 64-Bit systems:

session required /lib64/security/pam_limits.so

For 32-Bit systems:

session required pam_limits.so

Always check the location for pam_limits.so. The location depends on distribution or architecture.

For CentOS 6.x it is /lib64/security/pam_limits.so.

If you are unsure use find / -name pam_limits.so to locate pam_limits.so.

Creating folders for Oracle installation:

# mkdir -p /opt/app/oracle/product/11.2.0
# chown -R oracle:oinstall /opt/app
# chmod -R 775 /opt/app

Create a new profile archive

# vi /etc/profile.d/custom.sh

Add the following:

#!/bin/bash

if [ $USER = "oracle" ]; then
    if [ $SHELL = "/bin/ksh" ]; then
        ulimit -p 16384
        ulimit -n 65536
    else
        ulimit -u 16384 -n 65536
    fi
fi

Allow it to be executed:

# chmod +x /etc/profile.d/custom.sh

Change active users to oracle and edit ~/.bash_profile:

# vi ~/.bash_profile

Add the following:

umask 022
export TMPDIR=/tmp
export ORACLE_BASE=/opt/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2.0/db_1
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib
export PATH=$ORACLE_HOME/bin:$PATH

Execute ~/.bash_profile:

# source ~/.bash_profile