How to Repair Corrupt SQL Log File Transaction?

SQL Server log files store the transactions of the SQL database that a user executes to make any changes in the DB. To repair corrupt or deleted SQL log file transactions is significant in order to keep running the SQL database error-free. To rebuild SQL database with corrupted or deleted log files, users can try the T-SQL method, SSMS method, or even the modern-day utility.

This blog is going to address this problem of users & will provide them with the complete solution with all critical causes, top 3 solutions, and errors that originate because of this problem. Following the steps mentioned below can help users get the expected results with ease.

Why Rebuild SQL Database with Corrupted or Deleted Log File? All Causes

There are plenty of reasons due to which users might have been facing the deleted or corrupt state in SQL log files. In order to rebuild SQL database log transactions, here are some common causes that users must go through.

Accidental Deletion of the Log Files: Oftentimes, users tend to delete unwanted or already backed-up log files to create space in the database. However, sometimes, users accidentally delete the active log transactions which might result in severe consequences.

Software Glitches/Bugs to Tackle: Software issues like older SQL versions, loopholes in existing service packs, etc are also one of the reasons why users face damaged log files in their SQL database that require the rebuild process.

Large-Sized SQL Log Files: To learn how to repair SQL server database with a corrupt log file, users must admit to the fact that large-sized SQL log files often create issues while sharing, backup, etc operations leading to corruption or deletion.

Total System Crash Abruptly: A sudden system shutdown or power outage causing the interruption of ongoing operations can result in severe issues like incomplete I/O operations, malfunctioning of usual SQL queries, etc.

Hardware Issues: Lack of storage space, bad sectors in the storage disk, etc are some rare but existing hardware factors resulting in the damage of the usual transaction log file of SQL Server. Frequent SQL maintenance can prevent the need to repair corrupt SQL log file data.

Intentional SQL Attacks: SQL injection attacks, malware, viruses, etc are always there on the internet searching for a vulnerable database. Therefore, such attacks can also result in the deletion or corruption of the SQL Server database.

Common Errors Due to Deleted or Corrupt SQL Log Files

Now, if users are facing certain SQL Server errors, they must understand that it is because of the damaged log files in the database. Not al errors occur because of this reason but yes some do occur just because of this. Learning about these errors is beneficial to repair corrupt SQL log file easily.

SQL Server Error 9002

Msg 9002, Level 16, State 1, Line 1 The transaction log for database 'your_database_name' is full due to 'ACTIVE_TRANSACTION'. Truncate the log or change the recovery model to SIMPLE.

Due to active transactions or replication in the database, users might get this log file error as mentioned above.

SQL Server Error 15105

Operating system error 23 (failed to retrieve text for this error. Reason: 15105) on file “C:\Program Files\Microsoft SQL Server\MSSQL10_50.MYSERVER\MSSQL\DATA\TEST_DATABASE.ldf” during CheckLogBlockReadComplete

This error is related to the log file & operating system issues which results in a 15105 error code. Fixing the damaged or deleted log files can result in fixing of this error as well from its very root.

SQL Error in File Activation

File activation failure. The physical file name ‘C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\TEST_DATABASE.ldf’ may be incorrect. Diagnose and correct additional errors, and retry the operation.

FileMgr::StartLogFiles: Operating system error 2 (The system cannot find the file specified.) occurred while creating or opening file ‘E:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\DATA\TEST_DATABASE.ldf’. Diagnose and correct the operating system error, and retry the operation.

Actual issues in the physical files are counted here as file activation error. Thus, users need to rebuild SQL database with corrupted or deleted log file.

SQL Failure in Log File Attach

“Could not open new database ‘Your_DatabaseName’. CREATE Database is aborted”.

If the user’s log files are corrupted or damaged, it might show an error in attaching the log file which looks like this. Indeed, it’s a critical issue that users need to address.

How to Repair Corrupt SQL Log File – Best 3 Ways

We have two manual & one automated solution for users to fix this problem. The only difference in these solutions is because of the ease of execution, accuracy of the results, & presence of minor mistakes. All three solutions to rebuild SQL database with corrupted or deleted log file transactions are:

• Restore Database from a Backup File
• Advanced Automated Wizard for Ease
• Manual T-SQL Command Line Method

Go through the process of all these solutions & then select the ideal one. However, as per experts, the automated solution is the best one to get quick & accurate results.

Restore Database from A Backup File with SSMS – Method #1

1. Launch the SQL Server Management Studio (SSMS) to begin the task.
2. Right Click on Prefered database & Click on Restore Database option.
3. From the Source for Restore section, Click on Device & then proceed.
4. In Specify Backup Media, Click on the Add Button to add the BAK file.
5. Select the Desired Backup File to add & then Click on the OK button.
6. In the Select a Page Section, select the desired options as needed.
7. Click on any of the checkboxes & then Hit the OK button to Finish.

Repair Corrupt SQL Log File Automatically – Method #2

The automated method involves the best-in-class SQL Transaction Log Analyzer utility. Top IT experts & even Microsoft’s MVPs also recommend this utility for a clean execution. 

Just download the software & then follow the five simple steps to rebuild the corrupted or deleted transaction log data easily.

Step-1. Launch the Software & Click on Open to start the operation.

Step-2. Select the Online or Offline Mode for repairing the LDF files.

Step-3. Scan the Log Files (Offline) & Enter Server Details (Online).

Step-4. Preview the Log Files & Set the Destination Platform data.

Step-5. Select Corrupted/Deleted Objects & Click on Export button.

That’s it. With just these 5 steps, users can easily get the desired results & rebuild the damaged or deleted data files. This utility can also be used for the SQL log file analysis & forensics if ever needed. This way, users can fix error 3159 SQL Server as well.

Rebuild SQL Database with Corrupted or Deleted Log File with T-SQL – Method #3

Last but not least, the T-SQL solution is here. This method is quite technical & this is why only expert SQL users or the ones proficient in SQL commands can execute this one. Moreover, due to the reason of being quite technical, there are a little more chances for the users to face failures or get inaccurate errors.

Follow the steps as mentioned below:

1. Put the SQL Database in Emergency mode as shown in the below cmd.
   

   ALTER DATABASE  SET EMERGENCY, SINGLE_USER
   GO

1. Run the DBCC Command to continue as mentioned:
   

   DBCC CHECKDB ('TEST_DATABASE', REPAIR_REBUILD)

2. Run the below command if CHECKDB CMD does not work.
   

   ALTER DATABASE [original_log_file_name] REBUILD LOG ON (NAME= logicalname, FILENAME='C:\Program Files\Microsoft SQL Server\MSSQLn.MSSQLSERVER\MSSQL\DATA\TEST_DATABASE.ldf')

Note: The Repair_Rebuild clause might take longer than usual. Therefore, users can also opt for the Repair_Allow_Data_Loss option if they aren’t scared to loose data. Moreover, for quick results, Repair_Fast is another option.

The Final Say

Learning how to repair corrupt SQL log file with deleted or damaged data strings isn’t difficult anymore. This is because of the top three solutions mentioned above that can easily repair as well as rebuild the entire transaction log files as per the user requirements.

Here, users just need to be attentive in two places. The causes & the method. Identifying the right causes can lead to the solution & selecting an ideal method results as expected.