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Use

This strategy only backs up the database library. In the event of data loss, you can only recover data up to the point in time of the last backup. You must not use this strategy when you perform an online backup with partial transactions.

Recommendation

We recommend this strategy for test or training systems.

Prerequisites

  • This strategy requires journal receivers only for commitment control.

  • Journal receivers cannot grow beyond a maximum size of approximately 1 TB. To avoid filling journal receivers up to the maximum size, you need to define a threshold. If the journal attribute Manage receivers is set to *SYSTEM, the journal receiver is detached and a new receiver is created and attached automatically when the threshold is reached. The SAP installation defines a default threshold of 1500 MB.

Process

To set up journal management, you need to do the following:

  1. You plan your backup.

    Make sure that the database libraries are saved at regular intervals, such as weekly or daily. You can only use a backup method that saves the database in a consistent state (offline backup or online backup at a transaction boundary).

  2. If required, you need to change the threshold of the journal receivers.

    Note

    The default threshold of journal receivers is probably sufficient for most systems. If the threshold is too low for your system activity, this leads to frequent switches to new journal receivers, which might cause performance degradation. If the threshold is too high, the current journal receivers and the receivers (that are detached but not yet saved and deleted) might use up too much space. This can be a problem if you have configured a separate auxiliary storage pool (ASP) for your journal receivers.

    To change the threshold, you must create a new journal receiver by entering the command CRTJRNRCV THRESHOLD(<new value>). Then, you must switch the journal to the new receiver by entering the command CHGJRN JRNRCV(<new receiver>).

  3. You need to make sure that no other receivers except the currently attached one exist in the journal receiver library R3<SID>JRN (for SAP NetWeaver Application Server ABAP) or SAP<SID>JRN (for SAP NetWeaver Application Server Java). If detached journal receivers exist in the libraries, delete them by entering the command DLTJRNRCV.

  4. You need to change the journal receiver attributes of the journals R3<SID>DATA/QSQJRN (for SAP NetWeaver Application Server ABAP) and SAP<SID>DB/QSQJRN (for SAP NetWeaver Application Server Java) by entering the command CHGJRN JRN(<library>/<journal>) MNGRCV(*SYSTEM) DLTRCV(*YES).

For more information, see the IBM backup and recovery documentation.