ASMSNMP User Setup: Complete Oracle ASM Monitoring Guide

Have you ever encountered a frustrating situation where your Oracle Enterprise Manager couldn’t monitor your ASM environment, leaving you blind to storage issues? Recently, we faced this exact scenario with a client’s production ASM cluster, and ASMSNMP user comes to rescue.

The ASMSNMP user plays a crucial role in Oracle ASM (Automatic Storage Management), primarily enabling monitoring through Oracle Enterprise Manager (OEM). Without proper ASMSNMP configuration, you lose critical visibility into ASM performance and storage utilization.

In this comprehensive guide, we’ll cover:

✅ What is ASMSNMP and why it’s essential for production ASM
✅ Step-by-step ASMSNMP user creation using SQL*Plus
✅ Alternative ASMCMD method for user creation
✅ Security best practices and privilege management
✅ Troubleshooting common ASMSNMP configuration issues

This step-by-step guide ensures your ASM environment is properly monitored while following Oracle best practices.

Why ASMSNMP User is Critical for ASM

Oracle Automatic Storage Management (ASM) is a key component of database storage management, simplifying disk management and providing better performance. The ASMSNMP user is created specifically for Oracle Enterprise Manager (OEM) to monitor ASM instances.

What Made This Case Particularly Important:

In our recent implementation, the absence of proper ASMSNMP configuration led to:

• Undetected storage issues that caused downtime
• Missing performance alerts during peak usage
• Inability to track ASM disk group utilization proactively

Why ASMSNMP is Important:

OEM Monitoring: Required for Oracle Grid Control and Cloud Control to collect ASM-related metrics. Without this, you’re operating blind.

Security: Limits access to only monitoring functionalities, avoiding unnecessary permissions that could compromise your ASM environment.

Performance Insights: Helps track ASM storage utilization and detect potential issues early, preventing costly downtime.

Enterprise Compliance: Many organizations require comprehensive monitoring for audit and compliance purposes.

Creating ASMSNMP User with SQL*Plus

There are two ways of creating ASMSNMP User in Oracle ASM. Let’s start with the SQL*Plus method, which provides more granular control.

Step 1: Connect to the ASM Instance

Log in as the SYSASM user:

sql

sqlplus / as sysasm

Step 2: Check if ASMSNMP Already Exists

Before creating the user, verify if ASMSNMP already exists:

sql

SELECT username FROM v$pwfile_users;

If it is present, there is no need to create it again.

Step 3: Create the ASMSNMP User

If the user does not exist, create it with a secure password:

sql

CREATE USER ASMSNMP IDENTIFIED BY MySecurePassword;

Replace MySecurePassword with a strong password that meets your organization’s security requirements.

Step 4: Grant Necessary Privileges

sql

GRANT SYSDBA TO ASMSNMP;

For monitoring purposes, Oracle recommends using the SYSASM privilege instead of SYSDBA:

sql

GRANT SYSASM TO ASMSNMP;

Step 5: Verify User Creation

Run the following query to confirm:

sql

SELECT username, granted_role FROM dba_role_privs WHERE username='ASMSNMP';

Creating ASMSNMP User with ASMCMD

This alternative method uses ASMCMD utility, which many DBAs prefer for its simplicity.

Step 1: Open ASMCMD

Connect to ASM using ASMCMD:

bash

asmcmd

Step 2: Verify Current Users

List existing users:

bash

lspwusr

If user already exists, it will list the user. If not created already, use the steps below to create it.

Step 3: Create the ASMSNMP User

bash

mkusr ASMSNMP

Step 4: Assign a Password

bash

passwd ASMSNMP MySecurePassword

Step 5: Grant Necessary Privileges

bash

grantusr ASMSNMP SYSASM

Step 6: Verify User Creation

bash

lspwusr

This ensures that ASMSNMP is correctly set up for ASM monitoring using ASMCMD.

Security Best Practices

To enhance security in your production environment:

Password Management

Use a strong password and change it periodically:

sql

ALTER USER ASMSNMP IDENTIFIED BY NewSecurePassword;

Privilege Limitation

Limit access by restricting unnecessary privileges. The ASMSNMP user should only have monitoring-related permissions.

Auditing Configuration

Enable auditing to track usage:

sql

AUDIT SESSION BY ASMSNMP;

Network Security

Ensure ASMSNMP connections are encrypted and restricted to authorized monitoring servers only.

Troubleshooting Common ASMSNMP Issues

Based on our production experience, here are the most common issues and their solutions:

Issue 1: ORA-01918: User ‘ASMSNMP’ Already Exists

Solution: Use ALTER USER instead of CREATE USER:

sql

ALTER USER ASMSNMP IDENTIFIED BY MySecurePassword;

Issue 2: ASMSNMP Unable to Connect to ASM

Solution: Ensure the user has the correct privileges:

sql

GRANT SYSASM TO ASMSNMP;

Issue 3: ASMSNMP Fails in Oracle Enterprise Manager

Symptom: OEM shows connection errors for ASM monitoring

Solution: Update credentials in OEM → Targets → ASM → Monitoring Configuration.

Additional Verification:

sql

-- Test ASMSNMP connection
sqlplus ASMSNMP/password@ASM_instance as sysasm

Issue 4: Password File Corruption

Symptom: ASMSNMP user exists but cannot authenticate

Solution: Recreate the ASM password file:

bash

orapwd file=$ORACLE_HOME/dbs/orapw+ASM entries=10

Then recreate the ASMSNMP user following the steps above.

Post-Configuration Verification

After setting up ASMSNMP, verify the configuration works end-to-end:

Test ASM Connectivity

sql

-- Connect as ASMSNMP
sqlplus ASMSNMP/password as sysasm

-- Test basic ASM queries
SELECT name, state, type FROM v$asm_diskgroup;

Verify OEM Integration

1. Log into Oracle Enterprise Manager
2. Navigate to ASM targets
3. Verify monitoring data is being collected
4. Check for any credential or connection errors

Monitor ASM Metrics

Ensure the following metrics are visible in OEM:

• ASM disk group utilization
• ASM instance performance
• Storage allocation and free space
• I/O statistics and response times

Conclusion

The ASMSNMP user is essential for Oracle ASM monitoring, ensuring seamless tracking of ASM storage usage through Oracle Enterprise Manager. By following best practices in user creation, privilege assignment, and security, you can maintain a secure and efficient ASM environment.

The solution proved to be surprisingly straightforward once we understood the proper configuration sequence. This comprehensive setup prevents the monitoring blind spots that can lead to unexpected storage issues in production environments.

Let us know in the comments if you have questions about specific ASMSNMP configuration scenarios or if you’ve encountered other ASM monitoring challenges.

For related Oracle ASM topics, check our guides on Oracle ASM 19c installation and Oracle memory monitoring.