Support Portal

Welcome, Guest Login

Support Center

How to Restore a Microsoft SQL Server Master Database

Last Updated: Nov 08, 2018 10:48AM PST

Applies to...

  • DxEnterprise 15.0
  • DxEnterprise 15.5
  • DxEnterprise 16.0
  • DxEnterprise 17.0 for Windows
  • DxEnterprise 17.5 for Windows
  • DxEnterprise 18.0 for Windows
  • Microsoft SQL Server


Restoring the Microsoft SQL Server master database running on a DxEnterprise cluster.


This is very much the same as how you would do so with a stand-alone instance. There are really just two additional steps you need to take to successfully restore a master database:

  1. Freeze the VHost before restoring master
  2. Unfreeze the VHost after restoring master

The following is a general procedure that you can use to restore the master database:

  1. Remote Desktop into the active node that is currently hosting the instance
  2. Launch DxAdmin management console (formerly DxEnterprise management console)
  3. Right-click on the active node under the VHost and select "Freeze virtual host on node"
  4. Open Regedit and browse to the instance key (e.g. HKLM\Software\Microsoft\Microsoft SQL Server\<instance_name>\MSSQLServer\Parameters) and add SQLArg3 with string value of “-m”. This puts the instance under single-user startup mode so you can restore master. Restart the instance service to take effect.
  5. Restore master database. See for additional info.
  6. Once master is restored, again using Regedit to remove the single-user startup parameter. Restart the instance service to take effect.
  7. Back to the DxAdmin management console, right-click on the frozen node under the VHost and select "Unfreeze virtual host on node" to put the VHost back into normal operation again.

Contact Us
seconds ago
a minute ago
minutes ago
an hour ago
hours ago
a day ago
days ago
Invalid characters found