A SQL Server database can get corrupted or damaged due to sudden application or system shutdown, malware attacks, storage issues, software conflicts, and various other reasons. When the database gets corrupted, you can easily restore the backup database (.bak) file. While restoring the backup file, sometimes, you encounter various errors and issues or even fail to restore the backup. Some common errors that you may encounter are:
- Error 3183: Corrupt SQL Backup File
- The database cannot be recovered because the log was not restored
- Database cannot be opened. It is in the middle of a restore
- [Error Solved] SQL Database restore failed, database in use
Such errors usually occur if the backup file is corrupted, damaged, or unreadable. In this article, we will discuss the methods to restore the database if the backup file is also corrupted. To check the consistency errors in the database and recover from it, you can refer to this article.
Reasons for Corruption in SQL Database Backup (BAK) File
The backup file in SQL Server can get corrupted due to one or more of the below reasons:
- Bad sectors on the hard drive where the backup file is located.
- Malware or virus infection in the system hosting the BAK file/server.
- Sudden restart of the MS SQL Server instance.
- System shutdown suddenly while working on the backup database.
- Due to bugs in MS SQL Server.
Methods to Restore SQL Database if Backup File is Corrupted or Unreadable
If you are facing unexpected errors while restoring a SQL database, first make sure whether the backup file you are trying to restore is corrupted or not. For this purpose, you can use the RESTORE VERIFY ONLY command. This command helps to identify if the backup file can be read without any error. The command is mentioned below:
RESTORE VERIFYONLY
FROM DISK = ‘D:\Backup\YourDatabase.bak’;
If the backup file is corrupted or unreadable, then you can try the below methods to restore the database.
Method 1 – Run CONTINUE_AFTER_ERROR Command while Restoring SQL Database
If you face errors during the restoration of a corrupt or unreadable backup file, then you can try another SQL command CONTINUE_AFTER_ERROR. When you use this command, the server ignores the damaged/unreadable part of the file and continues the restore process. This method will work mostly in restoring the backup file that are having minor corruption issues. Below is the example of this command:
RESTORE DATABASE YourDatabase
FROM DISK = ‘D:\Backup\CorruptedFile.bak’
WITH CONTINUE_AFTER_ERROR;
Method 2 – Restore Database using a Third-Party SQL Repair Tool
If the backup file is severely corrupted, the only option is to use a third-party SQL database repair tool, like Stellar Repair for MS SQL Technician. This professional tool specializes in restoring data from corrupted or damaged SQL Server database backup files of any size or in any state. The tool can recover all the data, including indexes, tables, triggers, and stored procedures, with complete precision. It can effectively recover data from backups of all types, including Full, Differential, and Transaction log. It allows saving the recovered data from the corrupt backup file to a new database, live database, or other formats, such as CSV, HTML, XLS, etc.
Key features of Stellar Repair for MS SQL Technician:
- Repairs severely damaged or corrupted backup (.BAK) files and recovers all the data.
- Repairs primary and secondary database files.
- Recovers indexes, tables, stored procedures, views, keys, etc. with complete integrity.
- Allows specific recovery of objects.
- Allows to preview recovered data, including views, constraints, etc.
- Helps fix all types of database corruption errors
- Supports Windows 11, 10, 8.1, 8, 7 and Windows Server 2022, 2019, 2016, and earlier versions.
- Compatible with Ubuntu 16.04, 18.04, 19.10, CentOS 7, and Red Hat Enterprise Linux 7.
Conclusion
If your backup file is damaged, you may fail to restore the database (MDF/NDF) file. You can follow the methods mentioned in this post to restore the SQL database if the .bak file is corrupted. You can use Stellar Repair for MS SQL Technician to restore database file from the severely corrupted backup file. It can also help you repair the MDF/NDF files with complete integrity. The tool is compatible with all the SQL Server versions. You can try the tool’s demo version to scan the corrupt backup file and preview the recoverable data.