I’ve installed Oracle Database 11g Release 2 a few times on various Linux installs and apart from a few quirks it is a pretty similar process on most. The absolute bare bones default install, as described here, is easy to set up and doesn’t take that long. You can see more detail, including all the recommended steps if you follow the instructions in the Oracle install guide. I will describe installing 32bit Oracle Database 11g Release 2 on CentOS 6.3 32bit with the UI installed so we can use the Oracle installer directly. My computer’s name was “localhost.localdomain” as I was testing this in a development VirtualBox install.
First download Oracle 11g Release 2 from their website. For a linux install it comes as 2 zip files which you must first accept the license for before downloading. The exact version I downloaded was “Oracle Database 11g Release 2 (126.96.36.199.0) for Linux x86″.
Now you need to prepare your CentOS install by adding the required users and user groups for the install process. In my setup I am following oracle and running the following commands to add the “oinstall” and “dba” user groups:
Now add the “oracle” user, who we will be using to run the Oracle 11g install and give the user the correct group membership:
useradd -g oinstall -G dba oracle
Now create a directory and set the appropriate permissions where you are going to install Oracle. In my case I have installed it in the “oracle” user’s home directory under “/home/oracle/app”:
mkdir -p /home/oracle/app
chown -R oracle:oinstall /home/oracle/app/
chmod -R 775 /home/oracle/app/
Now extract the Oracle ZIP files downloaded earlier into somewhere sensible. I chose “/home/oracle/database”. Navigate to the directory and run the install script as your new oracle user:
NOTE: In my case, because this CentOS install was a VirtualBox virtual machine I needed to explicitly set the $DISPLAY variable to the local machine before the UI for the installer would run. This is done by running the following command and restarting my shell:
Now the installer will start up. You can ignore entering your email in the first step “Configure Security Updates” and leave the default setting of “Create and configure a database” in the second step “Installation Option”.
For the “System Class” step of the install I just left it as the default “Desktop Class” and in the “Typical Installation” step I left everything as default apart from setting the Administrative password. The default settings puts the oracle base in “/home/oracle/app/oracle” with a global database name of “orcl.localdomain”. For the “Create Inventory” step I left the default folder of “/home/oracle/app/oraInventory” and the group name “oinstall”.
Now we get on to the interesting part of the install, which is the “Prerequisite Checks” stage. If you are running the install on a brand new copy of CentOS you will need to set a few system variables and install a set of prerequisites.
NOTE: You may not need to, but I needed to add more swap space to my CentOS install this time around in order to meet the prerequisites. Run the following commands as root to create a 2048mb swap file called “/swapfile” on your harddrive and set CentOS to use it for swap space:
dd if=/dev/zero of=/swapfile bs=1024 count=2097152
Now set CentOS to always use this swap space at boot by editing your “/etc/fstab” file using the command:
And add the following line:
/swapfile swap swap defaults 0 0
So if you have passed the swap space test in the “Prerequisite Checks” in the Oracle install you can start to fix all those “Failed” messages. Click on the button “Fix & Check Again” and a window will pop up to tell you about the handy “runfixup.sh” script that will be placed in “/tmp/CVU_188.8.131.52.0_oracle/runfixup.sh”. So in your shell, navigate to the directory as root and run the script:
The “runfixup.sh” script will fix all the system variables for you so you don’t need to set them manually. Now all that remains is to fix the dependencies, most of which can be installed using “yum” with the following command:
yum install gcc gcc-c++ compat-libstdc++-33 elfutils-libelf-devel libaio-devel libstdc++-devel unixODBC unixODBC-devel
Now the only remaining prerequisite that causes a “Failed” message is “pdksh-5.2.14″ which has been removed from the CentOS repositories after CentOS 5 (see here). The replacement is “ksh” but if you install this package using “yum install ksh” you will get the same dependency check “Failed” in the Oracle install for “pdksh-5.2.14″ and “ksh” will conflict with “pdksh” if you then go to install it.
The solution is to install “pdksh” manually from RPM, which can be found at a variety of mirrors. I used the following command to install the “pdksh” package:
rpm -q ftp://ftp.pbone.net/mirror/archive.download.redhat.com/pub/redhat/linux/6.1/en/os/i386/RedHat/RPMS/pdksh-5.2.14-1.i386.rpm
Now Oracle should pass all the prerequisite checks and you will see the “Summary” step of the install where you can click the “Finish” button. It may take a while but Oracle Database will install with all the required settings ready for you to use out of the box.
The final step is to execute the configuration scripts as root, which will pop up after you have unlocked any users you might need other than the defaults (you don’t need to though at this stage). The two scripts can be run as follows:
To test your install worked you can log in to the web based management interface for your computer “localhost.localdomain” with the user name “SYS” connecting as “SYSDBA” and using the password you set during the install of Oracle. Remember to open port 1158 on your firewall if you need to:
Now you can start to use Oracle. I highly recommend looking through the documentation from Oracle themselves to help get yourself used to the Oracle way of doing things. There are loads of client applications that can help, like the command line based Oracle Instant Client and the Oracle SQL Developer UI program. Oracle have a lot of good walkthroughs for working with their tools which are available as part of their Learning LIbrary.