How to Fix "SQL Restore Operation Failed" Error - Guide for DBAs

Learn How to Fix "SQL Restore Operation Failed" Error - Guide for DBAs

How to Fix "SQL Restore Operation Failed" Error - Guide for DBAs

A healthy and accessible SQL Server database is crucial to keep your business up and running. It is indispensable to ensure its proper working condition. Now imagine the restore operation fails. How would you proceed as a database admin, is there a way out?

Well! It is possible to resume normal operations in this situation. It will need you to follow a systematic troubleshooting approach of reviewing the error message and logs of the corrupt database. 

Finding the root cause of the failed operation makes it easier to use the right restoration technique. Let’s discuss this topic in detail and learn more about the manual and automated methods to perform SQL repair.

What are the reasons behind the SQL database restore failed error?

Several common reasons behind the failure of a database restore operation are as follows:

1. Existing connections to the target database 

Having active connections to the target database is one of the most probable factors behind the failed restore operations. SQL Server requires exclusive access to multiple resources during restore.

If it finds any of the following possibilities, it blocks the database:

·        An application connection

·        A user session

·        An SQL agent job

·        Active maintenance tasks

·        An open query window having any association with the corrupt database

Eventually, the SQL Server will trigger the following error:

Exclusive access could not be obtained because the database is in use.

You can try any of the below-mentioned solutions to fix this issue:

• Set the database to Single_User mode or

• Terminate the currently active sessions to continue with the restore operation

2. Mismatched location of the source and target database files 

Often, the path of the original database file stored in the backup may not match with the target server, which can lead to a failed restore operation. This obstruction happens because of the recreation of the MDF and LDF files in their exact locations.

For example, consider the location of the source database files is on the D: drive. But the destination server has only a C: drive. This condition will result in a failed restore operation.

Using the WITH MOVE option during the restore operation can resolve this issue, as it will provide alternate locations for the database files.

3. SQL Server version compatibility issue

During a database restore from a backup, keeping a check at the version compatibility can avoid the possible errors. For example, to restore a SQL Server 2019 database, you should avoid choosing SQL Server 2016 or a lower version.

4. Permission issues

The SQL Server may not have the requisite read and write permissions to access the folders to which the backups are written. You can run backup statements in SQL Server manually or as part of database maintenance job. In any case, they run under the SQL Server service account, which requires the necessary privileges. Otherwise, you will get the error message. 

5. Disk space shortage

The target drive where you want to store the restored database may not have sufficient space to accommodate it and its files.

Method to Fix ‘SQL restore operation failed’ Error: Manual techniques

A failed restore error indicates the use of the database by another user or application. Here are the steps you can use to fix the SQL database restore failed error manually.

1. Check the active connections  

The foremost step to fix this error is to check all the active connections to the database through the sp_who T-SQL command and then disconnect them. Here is the command:

EXEC sp_who;

It will line up all the active sessions on the SQL Server instance. You need to check the entries where the dbname column displays the database that you want to restore.

2. Disconnect the active connections

Next, disconnect the active connections by setting the database to Single_User mode

Alter Database Testdb Set Single_User With Rollback Immediate;

The Rollback Immediate option will halt all the active transactions and immediately disconnect the existing users immediately.

3. Retry the restore operation

After disconnecting all the existing connections, retry the database restore process by using the command below:

Restore Database Testdb From Disk = 'C:\Backup\TestDB.bak' With Replace;

Here, by using the WITH REPLACE option, you can allow SQL Server to overwrite the existing database. Since it will replace the existing database with the contents of the backup file, use it carefully.

4. Set the database to Multi_User 

If the restore is a success, change the database to Multi_User mode to make way for routine operations. Here is the command:

Alter Database Testdb Set Multi_User;

5. Use DBCC CHECKDB to validate the restored database

After a successful restore, it is better to verify database integrity by using the DBCC CHECKDB command. It will help to find out the possibility of storage issues or corruption in the backup file despite the error-free completion of the database restore. Here is the command:

DBCC CHECKDB (TestDB)

 If the command displays the report of a clean database, you can make it available to users.

6. Use Repair options

If the database shows an error, you can use various repair options as given below to fix it immediately.

1.  DBCC CHECKDB ('TestDB', REPAIR_FAST);

This command can repair only minor database corruptions, non-critical allocation errors, and structural issues in previous SQL Server versions. It is not suitable to resolve advanced corruption issues and can fix only backward compatibility. In fact, Microsoft has marked REPAIR_FAST as deprecated in SQL Server 2012 and has completely removed/discontinued it from SQL Server 2016. If you have SQL Server 2017 or any later version, this command will do nothing.

2. DBCC CHECKDB ('TestDB', REPAIR_REBUILD)

This command can repair limited corruption and structural inconsistencies without causing data loss. It can also rebuild missing indexes.

3. DBCC CHECKDB ('TestDB', REPAIR_ALLOW_DATA_LOSS);

This command repairs major database corruption issues by deleting corrupted records, rows, and objects, or by deallocating damaged pages.

In spite of an unavoidable risk of data loss, use this option as a last resort. Before opting for it, experts recommend to back up the corrupted database and set it to Single_User mode.

Restrictions with manual ways to resolve the ‘SQL restore operation failed’ error

Manual ways to fix the SQL database restore error can work fine, but they have certain restrictions. While data loss is an obvious concern, especially in the case of REPAIR_ALLOW_DATA_LOSS, other issues keep causing problems. You need to have deep technical knowledge to perform the correct commands and seek all the required permissions before proceeding with the restore. In case of extremely severe corruption, or in the absence of a recent database backup, manual methods may not work as expected. To remedy this situation, admins use SQL database repair tools as a suitable alternative.

Use SQL Database Repair Tool to fix ‘SQL restore operation failed’ error

The modern-day advanced SQL database repair applications can help to deal with the SQL database restore failed error successfully. They are quick, efficient, and retain data integrity and consistency while performing the repair.

Here are more features you can avail from these advanced tools:

• Set your database free from SUSPECT mode

• Resolve the RECOVERY PENDING issue

• Fix the errors returned by the DBCC CHECKDB command

• Detect the corruption instantly and proceed with the resolution

• Ease of fixing the corruption online without requiring the installation of the software

Notably, Stellar Repair for MS SQL includes all these features, making it a promising alternative to manual database restore methods. You can also try online SQL repair service to repair an MDF file of up to 500 MB for free. Using it is easy; all you need is to upload the corrupt MDF file as large as 5 GB, and start repairing it within minutes. 

Conclusion

Several reasons can cause your database restore operation to fail. These may include a lack of appropriate permissions, insufficient disk space, mismatched paths of source and destination files, and more. To deal with this issue, you can opt for manual resolution, consisting of a series of steps. 

However, considering the involvement of ingrained technical aspects and a significant use of T-SQL commands, the manual method may appear cumbersome. Moreover, it is likely to pose a major threat of data loss when you use the DBCC CHECKDB command with the REPAIR_ALLOW_DATA_LOSS option. 

To avoid these issues, it is better to use an automated solution in the form of an advanced SQL database repair tool. Considering the heavy inflow of such tools in the market, it is better to use one recommended by industry experts, such as Stellar Repair for MS SQL.  

Now, you can also use it as an online SQL repair service to repair your corrupt database over the web, without the need to install the software. Being quick, efficient, and free form data loss make it a feasible solution to deal with the SQL database restore failed error successfully.