How to Install Oracle Database in Linux Centos

This installation tutorial is made using Oracle database 11g on a Linux Centos 6 – 64 bit machine. For installation of Oracle database on a Linux Centos 7, I recommend using Oracle 12g because in my experience installing Oracle database 11g on Centos 7, there is a graphical issue where the popup dialog on the installation interface will not be shown.

This tutorial assumes the user has already have a Linux Centos installed on their local machine and also has a basic knowledge of Linux command line application. First of all, obtain a copy of Oracle database on this link: http://www.oracle.com/technetwork/database/enterprise-edition/downloads/index.html

Since this tutorial is using a Linux Centos 6 – 64 bit machine, we will be using Oracle 11.2.0.1.0 for Linux x86-64. Download all the files that are provided on the link (File 1 and File 2), and after you have finished the download, you will have these files:

Installation Prerequisites

Before we begin to install Oracle 11g to our Linux Centos machine, we have to do some prerequisites task. Open up a terminal application on the Linux Centos machine, and change to root user by typing the command:

su – root

Next, we need to setup a user and usergroup that will have the authority to execute and manage the Oracle database. You can actually use root user to do this but as a best practice, always use different user for different functionality. Therefore, we want to create a user named oracle which will have the privilege to execute and manage oracle database function. On the terminal as root user, do the following command:

/usr/sbin/groupadd -g 501 oinstall
/usr/sbin/groupadd -g 502 dba
/usr/sbin/groupadd -g 503 oper
/usr/sbin/useradd -u 502 -g oinstall -G dba,oper oracle

After we have successfully created the user oracle for our Oracle database system, set the password for user oracle by typing:

passwd oracle

After we have successfully create an oracle user for our oracle database installation, we need to tune the Linux kernel’s parameter. Edit the sysctl.conf file by typing vi /etc/sysctl.conf (or you can use any text editor application to your preference) and insert the following line into the file:

kernel.shmmni = 4096
kernel.shmmax = 4398046511104
kernel.shmall = 1073741824
kernel.sem = 250 32000 100 128

fs.aio-max-nr = 1048576
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 = 1048586

Note: Inside the existing sysctl.conf, there are already kernel.shmmax and kernel.shmall variables defined. So, make sure to comment those out so there wouldn’t be any variables duplication. After you have save the changes you made on sysctl.conf, apply the kernel parameter by executing /sbin/sysctl -p.

Next part is to set shell limits to the oracle user. The shell limits configuration is stored in the /etc/security/limits.conf directory, so open the file on a text editor application and insert the following line:

oracle soft nproc 131072
oracle hard nproc 131072
oracle soft nofile 131072
oracle hard nofile 131072
oracle soft core unlimited
oracle hard core unlimited
oracle soft memlock 50000000
oracle hard memlock 50000000

Now, we need to set-up a valid hostname for the Linux machine. You can change the hostname configuration inside the /etc/hosts file. Insert a valid IP of your local machine and the hostname it will have. In this installation, we don’t change the configuration and decided the hostname will be localhost.

As a side note, you can verify whether your hostname configuration is correct by doing a ping command in the Linux command line application. The next step now is to modify the .bash_profile file for user Oracle. The .bash_profile file is an automated file script that is executed whenever we login as a user, so the objective of modifying the .bash_profile file for user Oracle is to set up the necessary environment setting for oracle database to operate.  Go to oracle user home directory (/home/oracle) and modify the .bash_profile file by inserting:

# Oracle Settings
export TMP=/tmp

export ORACLE_HOSTNAME=localhost
export ORACLE_UNQNAME=aci
export ORACLE_BASE=/ora01/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2.0/db_1
export ORACLE_SID=aci

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

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

alias cdob=’cd $ORACLE_BASE’
alias cdoh=’cd $ORACLE_HOME’
alias tns=’cd $ORACLE_HOME/network/admin’
alias envo=’env | grep ORACLE’

umask 022

Take note on the value of ORACLE_HOSTNAME, ORACLE_UNQNAME, ORACLE_BASE, ORACLE_HOME, and ORACLE_SID on this .bash_profile file we modify.

• ORACLE_HOSTNAME: Refers to the hostname of the machine that the oracle database is installed. If you are not sure what hostname your machine is set, you can type hostname on the command line.
• ORACLE_UNQNAME: Refers to the unique id that will identify your oracle database installation.
• ORACLE_BASE: The installation directory of the oracle that we will install later on.
• ORACLE_HOME: The installation directory which we will extract the oracle installation to.
• ORACLE_SID: The service name of the Oracle database to connect to later on.

Oracle database needs some packages to function, so do a package check on the command line by typing:

rpm -q –qf ‘%{NAME}-%{VERSION}-%{RELEASE}(%{ARCH})\n’ binutils \
elfutils-libelf \
elfutils-libelf-devel \
gcc \
gcc-c++ \
glibc \
glibc-common \
glibc-devel \
glibc-headers \
ksh \
libaio \
libaio-devel \
libgcc \
libstdc++ \
libstdc++-devel \
make \
sysstat \
unixODBC \
unixODBC-devel

In this tutorial case, the command line responded with:

Therefore, try to install the missing packages that the Oracle database needs. You can install packages in Linux by typing yum install <package name>. In this particular tutorial case, we install the missing packages as follows:

yum install elfutils-libelf-devel gcc gcc-c++ ksh libaio-devel libstdc++-devel unixODBC unixODBC-devel

The next step now is to make the corresponding directory based on the ORACLE_HOME and ORACLE_BASE value that we have set in the .bash_profile for oracle user. In this tutorial case, the directory that we need to create is /ora01/app/oracle/product/11.2.0/db_1. You can create directory using the command line by inputting:

mkdir -p /ora01/app/oracle/product/11.2.0/db_1

Don forget to set write and read access to all user in this folder so we can extract the oracle installation file in this directory:

chmod 777 -R /ora01

After that, unzip the oracle database installation file by typing:

unzip linux.x64_11gR2_database_1of2.zip

unzip linux.x64_11gR2_database_2of2.zip

Move the extracted files (don’t copy the database folder but go into the database folder then copy all the files inside it) to the ORACLE_HOME directory (/ora01/app/oracle/product/11.2.0/db_1). So, in the end, you will have this kind of arrangement in your ORACLE_HOME folder:

Now, set the owner and permission for this folder so only oracle and dba group can manage the folder (Not a must but consider a good practice):

chown oracle:oinstall /ora01/app
chmod 775 /ora01/app
chown oracle:oinstall /ora01/app/oracle
chmod 775 /ora01/app/oracle
chown oracle:oinstall -R /ora01/app/oracle

The next step is to disable secure Linux. The configuration can be found in etc/selinux/config. Edit the file using a text editor and edit the following variable inside the file:

SELINUX=permissive

Now that we have finished our prerequisites setup, we are ready to install Oracle database to our Linux machine.

Installing Oracle Database

First of all, you have to change to user oracle to start the Oracle database installation:

su – oracle

After that, type cdoh on the command line, this should automatically change to the ORACLE_HOME directory. To start the installation, type ./runInstaller in the command line and it will show the Oracle database graphical installation interface.

Troubleshooting: There are some cases where we type ./runInstaller, the checks will fail to check the graphic module by stating the system can’t open display. If this issue occurs, please refer to this link to apply for the fix: https://knowledgejunk.net/2017/07/27/how-to-solve-cant-open-display-error-on-installing-oracle-on-linux/

Now, uncheck the checkbox and click next to proceed. Select the Create and configure a database option and click next.

Now, in the System Class part, choose Server Class and click next.

Choose Single instance database installation option and click next.

In the Install Type section, choose Typical Install and click next.

Set your database name and your administrative password and press next.

Don’t change anything in the Create Inventory section and click next.

Check the Ignore All check box if there is a failed check item and press next.

Click Finish.

Wait until the Oracle database installation is finished.

After the installation has reached 100%, you will be prompted to execute two scripts that are displayed on the Oracle database installation. Therefore in the command line as a root user, execute both scripts provided.