How to Repair Master Database in MS SQL Server?

  •   Written By
  • Published on
    April 9th, 2014
  • Updated on
    March 16, 2021
  • Read Time
    4 minutes

Master Database is very important for a SQL server, as it holds the primary configuration details of the SQL server. It contains the complete information of all database pointers, all the users and their login credentials. Any kind of corruption in it can cause a data loss in the master database file. This blog will help you to repair corrupt/damaged database. Here, I will be discussing how to repair master database in MS SQL Server easily. Before moving further, let’s first know the symptoms and reasons for master database corruption.

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What Leads to Master Database Corruption

There are certain incidents which indicate that SQL master is having some corruption-related issues like:

Segmentation fault and input/output errors: Corrupt database can result in making various errors.

SQL Server could not be started: It is quite difficult to start if the master database file gets damaged.

DBCC report mentioning inconsistency: DBCC will notify you if the master database is not well.

Causes Behind Damaged SQL Master Database

There are many reasons that can damage your master database file in SQL Server Database.

  • One of the main causes of database corruption is the unstable power connection. Thus, it makes the Server to boot again. Though, the Server fails to start after reboot as the database has become corrupt.
  • The malware attack can also be the reason behind this situation.

If there is a corruption in your master database, then you have to either retrieve it from backup or rebuild the database. Since rebuilding is a lengthy and complex process, it’s better to restore the SQL master database.

Note: It is good to have the backup of a complete database no matter which method you adopt to repair master database of SQL Server.

How to Repair Master Database in SQL Server

Follow the below methods to repair Master Database in MS SQL Server.

Method #1: Fix Corruption From Backup File

If you have a backup of your database, then you can easily retrieve the data from it. Just make sure that backup database should belong to the same version of SQL Server as the corrupt database. Follow the below steps.

  1. First of all, retrieve the database backup of another instance.
  2. Then, go to the Database section of the Database dialog box. You have to use an alternate name like recover_master for the databases. Doing this will help to avoid any type of conflict regarding the database name.
  3. User can rename the MDF file as mdf and LDF file as recover_master_1.ldf.
  4. After that, detach the new database called recover_master.
  5. Now, open the file system to copy the database files recover_master.mdf and recover_master_1.ldf to the corrupt database instance.
  6. You are required to delete the damaged MDF and LDF files. Then, Rename the backup files (recover_master.mdf and recover_master_1.ldf) as mdf and mastlog.ldf.
  7. Finally, start SQL Server again and see if it works or not.

Method #2: Remove Corruption by Rebuilding Database

If in case, you do not have the master database backup, then you will not be able to retrieve that. In that situation, you have to rebuild the SQL system database using the below command.


Alternate Method to Repair Master Database

The above-mentioned methods do not guarantee to repair master database from SQL Server and might result in data loss. So, the most proficient technique to repair the SQL Server master database is using SQL Database Recovery tool. This software is highly capable in repairing the SQL database with great ease. It also repairs corrupt MDF and NDF files of SQL Server database. The tool offers multiple features to the users and it is suggested you must try the free demo version of this software.


The blog is describing the methods to repair master database in MS SQL Server. As the manual techniques can result in data loss so you must take the help of an automated tool. Hope it helps to resolve your query.

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