Fix SQL Server Error 5171 Fast – Expert Solutions & Guide

What is SQL Server Database Error 5171?

SQL Server Error 5171 comes about when SQL Server is unable to read or verify the MDF (Master Database File) while performing a database attach operation. It indicates that the MDF could either be damaged, corrupted, or otherwise a non-readable, invalid primary database file. When this error occurs, the SQL Server displays a message similar to:

It can have the ability to attach to the database and cause disruption to your database operations.

Frequent Causes of SQL Server Error 5171

There are various factors that can contribute to SQL Server Error 5171 when attaching a database.

• The primary (MDF) file of the database could have a corrupt header, or it could be corrupted internally.
• If a database is not properly detached before copying the database, SQL Server does not recognize it as valid.
• All databases have a log file (LDF). An incompatible LDF file may prevent the attachment of the database.
• If you attempt to attach a database that was created on a later version of SQL Server, the error may occur.
• Any unplanned premature termination of a database being used could corrupt the MDF file.

What It Means When You See “Not a Primary Database File”

This message means SQL Server cannot read the MDF file as a valid primary database. There are several reasons this can happen:

• This means that the MDF’s first 8KB header page (or other internal pages) are corrupt, meaning SQL Server cannot read them properly.
• Some common causes are unexpected shutdowns, malware attacks, and hardware failure.
• You may have tried to attach a backup (.bak) file or a secondary file (.ndf) instead of the MDF file.
• If you try to attach an MDF that was created by a newer version of SQL Server, it will not work.
• There may also be an issue with the log file that is indirectly causing the error.
• Sometimes this is caused by invalid registry entries related to SQL Server.

Best Ways to Resolve Microsoft SQL Server Error 5171

There are numerous ways to resolve this error depending on the circumstances. Below, we have highlighted them.

Method 01: Repair Corrupted SQL Error 5171 Manually

If you are dealing with mirrored databases and see this error when bringing a database online, take the following steps:

1. 1. Set the principal database.
   2. Change the reference for the file to:

   ALTER DATABASE mydb MODIFY FILE (NAME = ‘LogicalFileName’, FILENAME = ‘C:\NewPath\mydb.mdf’);

   3. Stop the active SQL Server instance.
   4. Navigate to the folder that contains your database files.
   5. Copy both MDF and LDF files to a safe place.
   6. Start the active SQL Server instance again.
   7. Stop the active SQL Server instance.
   8. Navigate to the folder containing your database files.
   9. Copy both MDF and LDF files to a safe location.
   10. Restart the SQL Server instance.

   Method 02: SQL Server 5171 Error Due to Improper Upgrade

   1. This error can also occur after an upgrade of SQL Server. For example, if you try to attach an MDF file from SQL Server 2014 to SQL Server 2016, you may receive:

   “MDF is not a primary database file” (Error 5171)

   2. To fix this, you can run the sp_attach_db command:

   EXEC sp_attach_db @dbname = N’YourDatabaseName’, @filename1 = N’C:\DatabasePath\YourDatabase.mdf’, @filename2 = N’C:\DatabasePath\YourDatabase_log.ldf’;

   3. This fixes version mismatch errors but may not work if the MDF file is too corrupted.

   Drawbacks of Manual Techniques

   • No assurance of full recovery of SQL data.
   • The possibility of losing important data.
   • Not feasible for severely corrupted files.
   • Requires technical and command-line skills.

   In order to avoid the drawbacks, we recommend having a professional recovery tool.

   Method 03: Fix the SQL Server Error 5171 within a Few Clicks

   The Aryson SQL Database Recovery Tool is one of the best options for resolving SQL Server Error 5171. It can repair corrupted or damaged MDF files and return all database objects without losing any data. In addition to its advantageous features, it can recover MDF and NDF files of a database with total accuracy and restore all tables, views, indexes, triggers, and stored procedures. Additionally, it can recover database files of different sizes, have different recovery options, and add a preview option prior to saving. The software has a straightforward interface, meaning that it is easy for users to run the software, regardless of their technical background.

   Simple Steps to Repair Error 5171 SQL Server:

   1. Firstly, launch the SQL Database Recovery Tool as an administrator.
      
      
   2. Choose Open and locate the corrupted MDF file on your computer.
      
      
   3. Select Standard Recovery Mode or Advanced Mode for the required search.
      
      
   4. Preview from the database objects within the corrupt database.
      
      
   5. Finally, choose which file(s) to save and select the ‘Save SQL Data’ to save the database.
      
      

   Additionally, Users might also find the SQL Error 1067.

   Conclusion

   In conclusion, SQL Server Error 5171 may affect the database operations, but specific ways to fix it. Manual methods can often be useful for small file corruption or version mismatch. These methods have limitations that may lead to a potential risk of losing data. Aryson SQL Database Recovery Tool is an effective, secure, reliable, and accurate solution to recover corrupted MDF files. It can also restore all parts of the database to resume the business function and reduce interruptions.

   Frequently Asked Questions:

   Q.1 What is SQL Server Error 5171?

   Ans: SQL Server Error 5171 occurs when the database file (MDF) is not recognized as a valid file by SQL Server. It usually prevents the database from being attached or restored.

   Q.2 What causes SQL Server Error 5171?

   Ans: This error is commonly caused by MDF file corruption, incomplete database file transfers, sudden system crashes, malware attacks, or mismatched SQL Server versions.

   Q.3 How can I fix SQL Server Error 5171?

   Ans: You can fix this error by restoring the database from a recent backup, using the attach database command with proper settings, or by repairing the MDF file with a reliable SQL recovery tool.

   Q.4 Can I recover a corrupted database file with SQL Server Error 5171?

   Ans: Yes, you can recover a corrupted database file using the Aryson  SQL database recovery software. This tool can repair MDF and NDF files and restore all database objects without data loss.

   Q.5 What is the best software to fix Error 5171?

   Ans: One of the most recommended tools is the Aryson SQL Database Recovery Tool. It offers safe recovery, supports large databases, and works with all major SQL Server versions.

   About The Author:

   

   Adom Smith

   Adom Smith is a DataRecoveryHelp Technology Writer. He is a technology enthusiast with over 3 years of experience in Data Recovery, IoT, Artificial Intelligence, and Robotics. He enjoys researching and sharing DIY solutions as well as tips and tricks for resolving Windows technical issues.

   Realted Post

   

   Fix SQL Server Error 40 – Complete step-by-step full guide

   

   Fix MySQL Error 1064 Now – Quick Solution Guide

   

   How to Resolve SQL Server 18456 Error Quickly