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Function documentation Backing Up Log Entries Locate the document in the library structure

Use

If, due to a system failure, the database system was not able to write the last data changes to the data area, after a restart it can repeat these last data changes with the redo log entries from the log area (see Using Log Entries for a Restart or Restore).

If the log area was damaged by the system failure, the database system can only restore the last database state if log backups are available on backup media. Therefore, back up the contents of the log area to backup media regularly.

You can perform log backups in the ONLINE operational state.

Caution

The database system can only overwrite saved segments of the log area with new redo log entries. If the database system cannot write any more redo log entries because the log area is full, the database shuts down. Exception: You have activated overwrite mode for the log area (see Log Settings).

When the log area gets full, execute a log backup.

Types of Log Backup

Name

Description

Automatic log backup

As soon as a log segment in the log area is full, the database system backs it up to a version file. Afterwards it releases the log segment in the log area to be overwritten.

Recommendation

We recommend automatic log backup in particular for database instances in which a large amount of data is changed and therefore a great number of redo log entries is expected.

Interactive log backup

With the Database Manager, you back up all redo log entries that the database system has written to the log area since the last log backup from the log area to a backup medium.

See also:  

Backup Media

Supported Backup Tools from Other Providers

Prerequisites

·        Automatic log backups are performed by the database system in the ONLINE operational state only.

·        Interactive log backups can be performed in operational states ONLINE or ADMIN.

·        To be able to perform a log backup, the current database instance has to have created at least one complete data backup.

·        You have created a backup medium.

Caution

For automatic log backup, only version files are permitted as the backup medium.

Activities

To execute a log backup, use the Database Manager, or the CCMS in SAP systems. The programs support the use of different types of backup media and different devices, including backup tools from other providers.

Note

As long as automatic log backup is active, you cannot start an interactive log backup. However, you can perform a data backup at the same time.

You cannot perform any other backup while an interactive log backup is running.

Activating Automatic Log Backup

·        Database Manager GUI, Activating and Deactivating Automatic Log Backup

·        Database Manager CLI, Activating Automatic Log Backup

·        Database Administration in CCMS, Structure linkActivating Interactive Log Backup

Executing Interactive Log Backups

·        Database Manager GUI, Backup Procedures

·        Database Manager CLI, Backing Up and Restoring Database Instances

·        Database Administration in CCMS, Structure linkScheduling Interactive Log Backups

Archiving the Version Files

For log backups to backup media of the file type, you have to archive the version files regularly.

See also:  

Backing Up and Restoring

 

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