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Procedure documentationChanging the Log Mode Locate this document in the navigation structure

 

The log mode specifies whether the database system uses software-based mirroring of the log volumes (default value: no mirrored log volumes). When software-based mirroring is activated, the database system writes redo log entries to two log areas in parallel (primary and secondary log area).

Note that the database system can only overwrite the log areas with new log entries after the log entries in the primary log area have been backed up.

Recommendation Recommendation

Only use mirrored log volumes if hardware-based mirroring, for example using a RAID system, is not possible. Software-based mirroring reduces the performance of your database system.

End of the recommendation.

Caution Caution

After changing the log mode, the database is restarted automatically.

End of the caution.

Prerequisites

You are logged on to the database as the database system administrator or as a DBM operator with server authorization for accessing database parameters (read and write) (see Glossary, Server Permission).

Procedure

Creating a Mirror Log Volume and Starting the Mirroring of the Log Area

  1. Select the database in the explorer tree.

  2. In the context menu of the database, choose   Administration Tasks   Change Log Settings...  

  3. Choose Log Mode.

  4. Specify name and location of the log volume that is to be mirrored.

    Specify name and location of the mirror log volume.

  5. Choose Start.

Stopping the Mirroring of the Log Area

  1. Select the database in the explorer tree.

  2. In the context menu of the database, choose   Administration Tasks   Change Log Settings...  

  3. Choose Log Mode.

  4. Choose Start.

More Information

Concepts of the Database System, How Databases Log Data Changes