When working with SQL Server, it is not uncommon to encounter permission-related errors that can be challenging to troubleshoot. One such error is Error 5120, which occurs when attaching MDF and LDF files to a SQL instance. In this article, we will explore the concept of permissions in SQL Server and discuss how to fix Error 5120.

What are Permissions in SQL Server?

Permissions in SQL Server determine the level of access and control that users or service accounts have over databases, tables, stored procedures, and other database objects. These permissions can be granted or revoked to ensure data security and integrity.

Understanding Error 5120

Error 5120 is a common error that occurs when attaching database files to a SQL instance. The error message typically states that the database is read-only and may include additional information such as operating system errors and file activation failures.

To fix Error 5120, it is important to identify the root cause of the issue. In many cases, the error is caused by insufficient permissions on the database files or folders.

Fixing Error 5120

To fix Error 5120, follow these steps:

1. Open the SQL Server Configuration Manager to find the service account associated with your SQL instance. The service account will vary depending on the SQL Server version.
2. Right-click on the database file (MDF/LDF) or folder and select “Properties”.
3. Go to the “Security” tab and click the “Edit” button.
4. Click the “Add” button and enter the object name as the service account found in the previous step.
5. Click the “Check Names” button to validate the service account.
6. Click “OK” to save the changes.
7. Give the service account “Full control” over the file or folder.
8. Click “OK” to save the changes.

After following these steps, you should be able to attach the database files without encountering Error 5120.

Conclusion

Permissions play a crucial role in SQL Server, and understanding how they work is essential for troubleshooting and resolving errors like Error 5120. By granting the appropriate permissions to the service account associated with your SQL instance, you can ensure smooth database operations and avoid permission-related issues.

If you have encountered similar permission errors or have any questions, feel free to share your experiences in the comments section below.