Oracle RAC Installation Guide: Step-by-Step Process

In this chapter, we’ll dive into the process of installing Oracle Real Application Clusters (RAC), covering everything from system requirements and pre-installation planning to the installation process and post-installation tasks. Oracle RAC enables high availability, scalability, and fault tolerance for your database environments by distributing workload across multiple nodes. Let’s explore each step in detail, complete with examples and commands.

1. System Requirements and Pre-Installation Planning

Before installing Oracle RAC, it’s critical to ensure that your system meets the hardware and software requirements. Here’s a checklist of requirements you need to consider:

System Requirements Checklist:

• Operating System: Oracle Linux, Red Hat Enterprise Linux, or SUSE Linux Enterprise Server (64-bit versions)
• RAM: Minimum of 8 GB per node
• Swap Space: At least the size of RAM or as recommended by Oracle
• Disk Space: Minimum of 30 GB for the Oracle software, plus additional space for data files
• Network Interfaces: Two NICs per node (one for public IP and one for private interconnect)
• Shared Storage: ASM (Automatic Storage Management) or NFS storage for the Oracle RAC database files

Pre-Installation Planning:

• DNS and Network Configuration: Ensure that each node has a public IP, virtual IP (VIP), and private IP.
• Software Version: Ensure that your database and operating system versions are compatible.

Verify the System Requirements with Commands:

# Check RAM
grep MemTotal /proc/meminfo

# Check swap space
grep SwapTotal /proc/meminfo

# Check available disk space
df -h

# Check network configuration
ip a

# Check operating system version
cat /etc/os-release

2. Hardware and Storage Configuration

For Oracle RAC, the hardware and storage setup plays a key role in performance and high availability. Here’s how to configure the hardware and storage:

Hardware Configuration:

• Multiple Nodes: Oracle RAC requires a minimum of two nodes.
• Network Configuration: Ensure that each node has a public and private network interface.
• Shared Storage: You can use ASM or shared file systems (such as NFS) to store Oracle RAC data.

Storage Configuration Example:

Using ASM (Automatic Storage Management) as a storage solution:

• Disks: Configure raw or block devices for ASM use.

Steps to Configure Shared Storage:

List available block devices:

lsblk

Mark a device for ASM use (example /dev/sdb):

oracleasm configure -i
oracleasm createdisk DATA /dev/sdb

Check the status of the ASM disks:

oracleasm listdisks

3. Setting Up Oracle Clusterware: Overview and Requirements

Oracle Clusterware is a key component of Oracle RAC, providing the infrastructure to manage multiple nodes as a single system. It includes essential services like cluster membership, node monitoring, and failure detection.

Oracle Clusterware Requirements:

• Shared Storage: Required for OCR (Oracle Cluster Registry) and voting disks.
• Network Configuration: Requires both public and private networks.

Commands to Set Up Oracle Clusterware:

Create the necessary directories for Oracle Clusterware:

mkdir -p /u01/app/19c/grid
chown -R oracle:oinstall /u01/app
chmod -R 775 /u01/app

Install the oracleasm and oracleasmlib packages:

yum install oracleasm-support oracleasmlib

Initialize the ASM service:

oracleasm init

4. Oracle RAC Installation (Step-by-Step Guide)

Step 1: Install Oracle Grid Infrastructure

Oracle Grid Infrastructure includes Oracle Clusterware and ASM, which are prerequisites for Oracle RAC. Begin by installing the Grid Infrastructure.

1. Start the Oracle Grid Infrastructure Installer: Download the Oracle Grid Infrastructure installer and execute the following:

./gridSetup.sh

1. Follow the Installer Steps:
   • Select Configuration: Choose “Configure Oracle Grid Infrastructure for a New Cluster”.
   • Cluster Name and SCAN: Provide a cluster name and Single Client Access Name (SCAN).
   • Network Configuration: Configure the public, private, and VIP networks.
   • Storage Configuration: Choose the ASM option and configure the ASM disks.
   • Review and Install: Review the configuration and complete the installation.

Step 2: Install Oracle RAC Database Software

Once Oracle Grid Infrastructure is installed, you can proceed with the Oracle RAC database installation.

1. Launch the Oracle RAC Installer:

./runInstaller

Follow the Installer Steps:

• Select RAC Installation: Choose “Install Oracle RAC Software Only”.
• Database Edition: Choose the edition (Enterprise or Standard).
• Nodes Configuration: Specify all nodes that are part of the RAC.
• Network Configuration: Configure public and private networks.
• Storage Configuration: Choose ASM for database storage.
• Install and Configure: Complete the installation and configuration.

5. Post-Installation Tasks and Verifying the RAC Setup

After installation, you need to perform some post-installation tasks and verify the setup to ensure everything is working correctly.

Post-Installation Tasks:

1. Verify Oracle Clusterware Status: Use the crsctl utility to verify that Oracle Clusterware is running properly.

crsctl check crs
crsctl status resource -t

Verify the ASM Configuration: Use the asmcmd utility to check the status of ASM and the disk groups.

asmcmd lsdg

Configure Oracle RAC Database Instances: Create the RAC database using DBCA (Database Configuration Assistant).

dbca

Verify the Database Configuration: Once the database is created, check that all RAC instances are running:

srvctl status database -d <db_unique_name>

Enable Monitoring: Configure Oracle Enterprise Manager or Grid Control for monitoring the Oracle RAC environment.

Conclusion

Installing Oracle RAC involves multiple steps, from verifying system requirements and hardware configuration to installing Oracle Grid Infrastructure and the RAC database. By following this guide, you can efficiently set up a highly available and scalable Oracle RAC environment. Post-installation tasks such as verifying Oracle Clusterware, ASM, and database configurations ensure that the environment is correctly set up and ready for use.