SQL T-Log Backup Failures with SQL74 Error Due to AUTO_CLOSE Database Setting

Problem Description

SQL Transaction Log (T-Log) backups fail intermittently with a SQL74 error. This issue typically impacts only specific databases, while other databases on the same SQL Server instance continue to back up successfully.

Traceback

The following error message appears in the Druva backup logs:

Error: SQL74 - Recovery_fork_guid returned NULL during transaction log backup. Unable to determine the recovery fork GUID for the database.

Cause

This issue occurs because the affected database has the Microsoft SQL Server AUTO_CLOSE property enabled.
When AUTO_CLOSE is turned on, SQL Server automatically shuts down and closes the database as soon as the last user session disconnects to free up system resources.
If a Druva T-Log backup triggers precisely while the database is transitioning between an offline (closed) and online state, the system cannot retrieve the database metadata (Recovery_fork_guid). This breaks the transaction log sequence tracking and results in a SQL74 failure.

Resolution

To resolve this issue, disable the AUTO_CLOSE option on the affected database. You can do this either graphically using SQL Server Management Studio (SSMS) or via a T-SQL query.

Method 1: Using SQL Server Management Studio (SSMS)

Open SQL Server Management Studio (SSMS) and connect to your SQL Server instance.
In the Object Explorer on the left, expand the Databases folder.
Right-click the affected database and select Properties.
In the Database Properties window, click on the Options page in the left pane.
In the right pane, locate the Automatic section.
Find AUTO_CLOSE and change its value from True to False.
Click OK to save and apply the changes.

Method 2: Using a T-SQL Query

Open a New Query window in SSMS.
Run the following command (replace [DatabaseName] with the name of your database):

ALTER DATABASE [DatabaseName] SET AUTO_CLOSE OFF;

ALTER DATABASE [DatabaseName] SET AUTO_CLOSE OFF;

Expected Result: If the is_auto_close_on value returns 0, AUTO_CLOSE is successfully turned off.

2. Verify Backup Success

Run a manual T-Log backup or wait for the next scheduled backup cycle. Monitor the Druva Management Console to confirm the job completes successfully without yielding the SQL74 error.