Procedure documentationBacking Up Log Entries Locate this document in the navigation structure


The database system stores information about data changes in redo log entries in the log area. Regularly back up your redo log entries from the log area to data carriers, because if the log area was damaged during a system failure, you need redo log entries from log backups to restore the database to the desired state.

If due to a system failure the database system could not write the latest data changes to the data area, but the log area was not damaged, you do not need backed-up redo log entries to restore the database to the state before the system failure. When you restart your database, the database systems uses redo log entries from the log area to repeat those data changes. More information: Example: Restart

Caution Caution

If the log area is full and the database system cannot write redo log entries to it any longer, the database comes to a stand-still. You can only continue working after you have backed up redo log entries from the log area to data carriers.

Exception: You have switched on the overwrite mode for the log area. This is not recommended in production systems though. More information: Glossary, Overwrite Mode for the Log Area

End of the caution.

Note that you cannot start any other backup while a log backup is running. Exception: When automatic log backup is active, you can perform data backups.



For log backups, use Database Studio, Database Manager CLI, or CCMS (in SAP systems only).

Manual Log Backup

During a manual log backup, you back up all redo log entries that the system has written since the last log backup.

You can back up log entries to files or to pipes. When backing up to files, the system creates the necessary files one after the other. Each file has the size of a log segment. Note that restrictions apply for backing up to pipes, see Backup Templates and Data Carriers.

More information:

Activating or Deactivating Automatic Log Backup

If automatic log backup is on, the database system automatically backs up redo log entries to backup files.

The system starts a log backup at the following times:

  • When a log segment is full

    You configure the size of the log segments with the general database parameter AutoLogBackupSize.

    More information: General Database Parameters

  • When the configured time interval has elapsed

    You can specify the time interval when switching automatic log backup on.

Recommendation Recommendation

We recommend automatic log backup in particular for databases in which large amounts of data are changed and therefore a great number of redo log entries are written.

End of the recommendation.

Caution Caution

For automatic log backup, you cannot use pipes.

More information: SAP Note 869267

End of the caution.

More information:

Archiving Backup Files

For log backups to files, you have to archive the backup files regularly.

More information: Archiving Backup Files

More Information

Concepts of the Database System, How Databases Log Data Changes

Restoring Databases