Here we are installing Oracle 11g Release-2 (11.2)(64-bit) on CentOS 6.x (64-bit)

Kindly have a look on Pre-requisites before proceeding for oracle 11gR2 installation.

Memory requirements:

Minimum 1 GB RAM, Recommended 2 GB or more than that.

Following commands will help you to determine RAM of your system:

 # grep MemTotal /proc/meminfo
 # free -m // shows RAM + SWAP

Note: If RAM of your system does not meet minimum requirement than increase it.

SWAP partition need for oracle installation is only depend on RAM installed in your system, according to oracle docs.

1. If your RAM between 1 GB to 2 GB than your swap partition size should be 1.5 times the size of the RAM.
2. If your RAM between 2 GB to 16 GB than your swap partition size should be equal to the size of the RAM.
3. If your RAM more than 16 GB than your swap partition size should be 16 GB.

Disk space requirement:

/tmp directory size would be at least 1 GB.

Determine available disk space of /tmp directory with following command:

# df -h /tmp

Minimum need of total disk space of the system would directly depend upon size of your database, Oracle installation files take maximum 4.5 GB to 4.7GB of disk space.

Determine total disk space available with following:

# df -h

Verify your system architecture with following command:

# uname -m

If you fulfill your h/w pre-requisites than make sure following changes in your system in order to install oracle smoothly:

Update host file “/etc/hosts” with fully qualified name like below:

[root@c11g ~]# cat /etc/hosts
...
192.168.17.145 c11g.localdomain c11g

Note:
In my case “c11g.localdomain” is fully qualified name with machine name.

Oracle public yum repository are easily available, Here we use “oracle-rdbms-server-11gR2-preinstall” package to download latest Oracle Linux dependencies automatically.

[root@c11g ~]# cd /etc/yum.repos.d
[root@c11g yum.repos.d]# wget https://public-yum.oracle.com/public-yum-ol6.repo
[root@c11g yum.repos.d]# ll public-yum-ol6.repo
-rw-r–r–. 1 root root 5046 Jan 29 13:15 public-yum-ol6.repo

Install following package with YUM in order to complete oracle database installation pre-requisites automatically.

[root@c11g ~]# yum install oracle-rdbms-server-11gR2-preinstall

Above package installation may failed with “GPG key retrieval failed“, for solution download and verify GPG key that complies CentOS 6.x with the help of following and continue.

Error: GPG key retrieval failed: [Errno 14] Could not open/read file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle

[root@c11g ~]# wget https://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 -O /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle

Create oracle groups and users:

 groupadd -g 501 oinstall
 groupadd -g 502 dba
 groupadd -g 503 oper
 groupadd -g 504 asmadmin
 groupadd -g 506 asmdba
 groupadd -g 505 asmoper

 useradd -u 502 -g oinstall -G dba,asmdba,oper oracle

Set password for oracle user:

[root@c11g ~]# passwd oracle

Add nproc parameter to the “/etc/security/limits.d/90-nproc.conf” file.

[root@c11g ~]# cat /etc/security/limits.d/90-nproc.conf
# Default limit for number of user's processes to prevent
# accidental fork bombs.
# See rhbz #432903 for reasoning.
* soft nproc 1024
root soft nproc unlimited
# To this
* - nproc 16384

Set SELINUX ‘permissive’ by updating file “/etc/selinux/config”

SELINUX=permissive

Note: Reboot server after setting SELINUX disabled.

[root@c11g ~]# reboot

Create directory for oracle software and assigned proper permission in order to install oracle s/w smoothly.

[root@c11g ~]# mkdir -p /u01/app/oracle/product/11.2.0/dbhome_1
[root@c11g ~]# chown -R oracle:oinstall /u01
[root@c11g ~]# chmod -R 775 /u01

On GUI, open terminal prompt as a root user & issue the following command:

[root@c11g ~]# xhost +
access control disabled, clients can connect from any host

[root@c11g ~]# su - oracle

Run universal installer and follow the steps by step installation of oracle 11gR2:

./runIstaller

And follow the steps mentioned below:

 

 

You can directly create and configure a database by selecting first radio button. Other options are available to install oracle software only ( Not database ) and to upgrade existing database.

 

Select “Desktop Class” if you are installing on desktop else select “Server Class” in case of Server installation.

 

Ensure “Oracle base”, “Software location”, “Database file location”, “Database edition” and continue.

Provide administrative password according to oracle standards and continue.

 

 

 

If your system already installed latest version of mentioned packages, then you can ignore and continue. In my case, latest version available.

 

Ensure summary and continue.

 

 

After installation successfully completed, set environment variables ( like ORACLE_SID, ORACLE_HOME & PATH ) from oracle user and access your database after database startup as follows:

 

Cheers!!

Installation of Oracle 11g Release-2 (11.2)(64-bit) on CentOS 6.x (64-bit) successfully completed.

Stay Tune. 🙂