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Pause or Resume a Database Mirroring Session (SQL Server)

Applies to: SQL Server

This topic describes how to pause or resume database mirroring in SQL Server by using SQL Server Management Studio or Transact-SQL.

In This Topic

Before You Begin

At any time, you can suspend a database mirroring session, which might improve performance during bottlenecks, and you can resume a suspended session at any time.

Caution

After a forced service, when the original principal server reconnects, mirroring is suspended. Resuming mirroring in this situation could possibly cause data loss on the original principal server. For information about managing the potential data loss, see Role Switching During a Database Mirroring Session (SQL Server).

Security

Permissions

Requires ALTER permission on the database.

Using SQL Server Management Studio

To pause or resume a database mirroring session use the Database Properties Mirroring page.

To pause or resume database mirroring

  1. During a database mirroring session, connect to the principal server instance, in Object Explorer, click the server name to expand the server tree.

  2. Expand Databases, and select the database.

  3. Right-click the database, select Tasks, and then click Mirror. This opens the Mirroring page of the Database Properties dialog box.

  4. To pause the session, click Pause.

    A prompt asks for confirmation; if you click Yes, the session is paused, and the button changes to Resume.

    For more information about the impact of pausing a session, see Pausing and Resuming Database Mirroring (SQL Server).

  5. To resume the session, click Resume.

Using Transact-SQL

To pause database mirroring

  1. Connect to the Database Engine for either partner.

  2. From the Standard bar, click New Query.

  3. Issue the following Transact-SQL statement:

    ALTER DATABASE database_name SET PARTNER SUSPEND

    where database_name is the mirrored database whose session you want to you want to suspend.

    The following example pauses the AdventureWorks2022 sample database.

    ALTER DATABASE AdventureWorks2022 SET PARTNER SUSPEND;  
    
To resume database mirroring
  1. Connect to the Database Engine for either partner.

  2. From the Standard bar, click New Query.

  3. Issue the following Transact-SQL statement:

    ALTER DATABASE database_name SET PARTNER RESUME

    where database_name is the mirrored database whose session you want to resume.

    The following example pauses the AdventureWorks2022 sample database.

    ALTER DATABASE AdventureWorks2022 SET PARTNER RESUME;  
    

Follow Up: After Pausing or Resuming Database Mirroring

  • After pausing database mirroring

    On the primary database, take precautions to avoid a full transaction log. For more information, see The Transaction Log (SQL Server).

  • After resuming database mirroring

    Resuming database mirroring places the mirror database in the SYNCHRONIZING state. If the safety level is FULL, the mirror catches up with the principal and the mirror database enters the SYNCHRONIZED state. At this point, failover becomes possible. If the witness is present and ON, automatic failover is possible. In the absence of a witness, manual failover is possible.

Related Tasks

See Also

Database Mirroring (SQL Server)