Here’s a detailed and unique step-by-step guide for Oracle 19c RAC Installation on Oracle Linux 7.9. This refined guide breaks down the process in depth to give you a solid understanding of each phase of the installation.

Step-by-Step Oracle 19c RAC Installation on Oracle Linux 7.9

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Oracle Real Application Clusters (RAC) provides database services with high availability, scalability, and flexibility by allowing multiple servers to run Oracle software and work together as a single system. This guide will take you through the step-by-step process of installing Oracle RAC 19c on Oracle Linux 7.9, from pre-requisites to the final setup.

Prerequisites

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Before beginning, ensure the following prerequisites are met:

1. Two or More Linux Nodes:

   • The setup assumes at least two nodes (node1, node2).
   • Ensure the servers have access to shared storage (either through iSCSI or NFS).

2. Operating System:

   • Oracle Linux 7.9 should be installed on both nodes.
   • Disable the firewall and SELinux as it may interfere with the RAC setup:

     systemctl stop firewalld
     systemctl disable firewalld
     setenforce 0
     

3. SSH Passwordless Authentication: Set up passwordless SSH between nodes:

   ssh-keygen -t rsa
   ssh-copy-id oracle@node2
   

4. Hosts File Configuration: Add public and private IPs for each node to /etc/hosts on both servers. Example:

   192.168.0.101  node1.localdomain node1
   192.168.0.102  node2.localdomain node2
   

5. Shared Storage: Provision and configure shared disks for the Oracle RAC setup. Ensure that both nodes can access the shared storage without any issues.

Part 1: Grid Infrastructure Installation

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Step 1: Preparing ASM Disks

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For Oracle RAC, shared disks will be managed by Oracle ASM (Automatic Storage Management). First, create and label ASM disks on both nodes.

oracleasm configure -i
oracleasm init
oracleasm createdisk DATA1 /dev/sdb
oracleasm createdisk FRA1 /dev/sdc

Ensure both nodes recognize the ASM disks by running:

oracleasm scandisks
oracleasm listdisks

Step 2: Installing Oracle Grid Infrastructure

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Download and Install Grid Software

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1. Download the Oracle Grid Infrastructure software from Oracle’s website and extract the files.
2. Run the installer on Node1:

   ./runInstaller
   

During the installation:

• Select Configure Oracle Grid Infrastructure for a New Cluster.
• Enter the cluster name and SCAN name (e.g., myrac-cluster and myrac-scan).
• Configure the ASM disk groups (DATA for database files, FRA for recovery files).
• Configure redundancy as per your requirement (normal, high, etc.).

After the installation, synchronize ASM on Node2:

oracleasm scandisks

Step 3: Verify Installation

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Check that the Clusterware and ASM are running:

crsctl check crs
crsctl check cssd

Part 2: Installing Oracle Database Software

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Step 1: Pre-Installation Checks

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Before installing the database software, run the Oracle preinstallation package to ensure your system meets all the Oracle prerequisites:

yum install -y oracle-database-preinstall-19c

This will install necessary packages and adjust kernel parameters.

Step 2: Installing Oracle Database Software

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1. Download Oracle 19c database software and extract it on both nodes.

2. Run the Oracle Universal Installer (OUI) on Node1:

   ./runInstaller
   

   • Select Oracle RAC Database as the installation type.
   • Include both nodes (Node1 and Node2) in the cluster configuration.
   • Choose Oracle ASM for storage, and select the DATA and FRA disk groups created during the Grid Infrastructure setup.

3. The installer will guide you through database-specific settings, including SID, character set, memory allocations, and more.

Step 3: Post-Installation Configuration

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Once the installation completes, perform the following steps to finalize the database setup:

Modify SQLNET.ORA (if needed)

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Modify the sqlnet.ora file on both nodes to avoid any authentication errors:

SQLNET.ALLOWED_LOGON_VERSION_SERVER=8
SQLNET.ALLOWED_LOGON_VERSION_CLIENT=8

Part 3: Configuring and Starting the RAC Database

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Step 1: Creating the RAC Database Using DBCA

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Run Database Configuration Assistant (DBCA) on Node1 to create the RAC database.

1. Launch the DBCA utility:

   dbca
   

2. Select Create Database, then choose Oracle RAC Database.
3. Follow the prompts to configure the RAC database, choosing the DATA and FRA ASM disk groups for storage.
4. Set up listener configurations, instance settings, and configure the database initialization parameters.

Step 2: Verifying RAC Setup

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After creating the database, verify that the RAC instances are running on both nodes:

srvctl status database -d orcl

This will show the status of all RAC instances.

Step 3: Manage RAC Services

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You can use SRVCTL to manage the RAC services:

• Start the database:

  srvctl start database -d orcl
  

• Stop the database:

  srvctl stop database -d orcl
  

Step 4: Testing the RAC Database

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Once everything is up and running, test the RAC database using SQL*Plus or any Oracle database management tool (like SQL Developer).

Example:

sqlplus / as sysdba
SQL> select instance_name from v$instance;

You should see both RAC instances listed, confirming that the RAC setup is complete.

Conclusion

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With the completion of this step-by-step guide, your Oracle 19c RAC on Oracle Linux 7.9 is successfully installed and running. This setup provides high availability, load balancing, and scalability for your Oracle databases. Regularly monitor and manage the database and clusterware to ensure smooth operations.

For further tuning and advanced configurations, you can explore Oracle’s documentation and online resources.