SSH Equivalency Setup in Oracle Exadata – Step-by-Step Guide

Introduction

SSH equivalency is a mandatory requirement in Oracle Exadata environments. It enables passwordless SSH communication between database servers, storage servers (cells), and other Exadata components.

SSH equivalency is used during:

• Exadata deployment

• OneCommand setup

• Patching activities

• Exachk execution

• Automation scripts

• Cluster operations

This guide demonstrates how to configure SSH equivalency securely in an Oracle Exadata environment.

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Environment Details

Example Exadata Environment:

Hostname	Type
db01	Database Server
db02	Database Server
cell01	Storage Server
cell02	Storage Server
cell03	Storage Server

User:

oracle

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Step 1: Verify Connectivity

From db01, verify connectivity to all nodes.

ping db02
ping cell01
ping cell02
ping cell03

Expected Result:

64 bytes from db02
64 bytes from cell01

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Step 2: Generate SSH Key

Login as oracle user.

su - oracle

Generate SSH key.

ssh-keygen -t rsa

Press Enter for all prompts.

Verify key files:

ls -ltr ~/.ssh

Expected:

id_rsa
id_rsa.pub

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Step 3: Copy Public Key to Remote Servers

Copy public key to all target nodes.

ssh-copy-id oracle@db02

ssh-copy-id oracle@cell01

ssh-copy-id oracle@cell02

ssh-copy-id oracle@cell03

Enter password when prompted.

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Step 4: Verify Passwordless Login

Test SSH connectivity.

ssh db02 hostname

ssh cell01 hostname

ssh cell02 hostname

ssh cell03 hostname

Expected Output:

db02
cell01
cell02
cell03

No password should be requested.

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Step 5: Configure Reverse Connectivity

Perform the same steps from db02 to db01.

Generate keys:

ssh-keygen -t rsa

Copy keys:

ssh-copy-id oracle@db01

Validate:

ssh db01 hostname

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Step 6: Validate SSH Equivalency

Execute the following command from each database node.

ssh db01 date

ssh db02 date

ssh cell01 date

ssh cell02 date

ssh cell03 date

All commands should execute without password prompts.

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Step 7: Verify Authorized Keys

Check authorized_keys file.

cat ~/.ssh/authorized_keys

Ensure public keys from all participating nodes are present.

Permissions:

chmod 700 ~/.ssh

chmod 600 ~/.ssh/authorized_keys

chmod 600 ~/.ssh/id_rsa

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Common Issues and Troubleshooting

Permission Denied

Error:

Permission denied (publickey)

Solution:

chmod 700 ~/.ssh

chmod 600 ~/.ssh/authorized_keys

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Host Key Verification Failed

Error:

Host key verification failed

Solution:

ssh-keygen -R hostname

Reconnect:

ssh hostname

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SSH Timeout

Verify:

ping hostname

nslookup hostname

Check firewall configuration.

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Validation Checklist

Check	Status
SSH keys generated	✓
Public keys copied	✓
Passwordless login working	✓
Authorized keys validated	✓
Permissions verified	✓

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Conclusion

SSH equivalency is a critical prerequisite for Oracle Exadata administration, patching, and automation activities. Properly configured passwordless SSH improves operational efficiency and reduces manual intervention during maintenance and deployment tasks.

Always validate connectivity and file permissions after configuration to avoid failures during patching and cluster operations.

Create a Free SQL Database in Azure and query using query editor

 

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How to Create a Free SQL Database in Azure (with Screenshots)

Getting started with SQL databases in the cloud is easy with Microsoft Azure. Follow the step-by-step tutorial below to create your own free Azure SQL Database and run queries using the Azure Portal.

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1. Log in to the Azure Portal

Go to https://portal.azure.com/ and sign in with your Microsoft account. On the homepage, you’ll find options like Create a resource, Azure SQL Database, and more.

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2. Create a New SQL Database

Click on Azure SQL Database or use the search bar to find it. Click the Create button to start the creation process.

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3. Configure Database Basics

Fill out the basic details:

• Subscription: Choose your Azure subscription.
• Resource group: Create a new resource group or select an existing one.
• Database name: Enter a meaningful name.
• Server: Click "Create new" to set up a SQL server (see next step).

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4. Set Up SQL Database Server

In the server creation form, provide:

• Server name: A unique name.
• Location: Select the Azure region.
• Authentication: Set admin login and password.

5. Configure Networking Options

On the networking screen:

• Set Allow Azure services and resources to access this server to No.
• Set Add current client IP address to Yes.​
  
  
  
  
  

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6. Additional Settings: Add Sample Data

On the Additional settings tab, choose Sample under “Use existing data”. This loads the AdventureWorksLT sample database for learning and testing.​

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7. Review and Create

Click Review + create at the bottom and let Azure deploy your database.

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8. Query the Database

Once deployed, go back to the list of your SQL databases and select the one you’ve just created.2_Create.jpg​

• Open Query editor (preview).
• Log in with the credentials you set for your server.
• 
  
  

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9. Sample Query and Output

Here’s how the query and results look in the Azure Portal’s Query Editor :​

sql

SELECT * FROM [SalesLT].[Customer]

You’ll see a result table with columns such as CustomerID, NameStyle, Title, and FirstName.