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Journal Setup for Save Strategy 1Locate this document in the navigation structure

Use

For this strategy you need to back up both the database libraries and the journal receivers. Journal receivers log all changes that are applied to the database.

In the event of data loss, you can recover data up to a point in time right before the data loss. You must use this strategy if you perform an online backup with partial transactions.

Recommendation

We recommend this strategy for production systems.

Prerequisites

  • This strategy requires journal receivers both for commitment control and for recovery.

  • 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 for this strategy, you need to do the following:

  1. You plan your backup.

    • You save the database libraries at regular intervals, such as weekly or daily.

    • You must save detached journal receivers before you can delete them. You can do this manually, or you can automate the process by entering the command SAVDLTRCV as described in SAP Note 82079 Information published on SAP site.

  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 impact performance. 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 the journal attributes are set to Manage receivers *SYSTEM and Delete receivers *NO.

    Note

    Check the current settings 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 WRKJRNA. If Manage receivers is set to *USER or Delete receivers is set to *YES, you must change the attributes by entering the command CHGJRN JRN(<library>/<journal>) MNGRCV(*SYSTEM) DLTRCV(*NO).

  4. You have to save and delete journal receivers that are detached using one of the following methods:

    • To save and delete journal receivers automatically, see SAP Note 82079 Information published on SAP site.

    • To save detached journal receivers, enter the command SAVOBJ. You must delete journal receivers manually after they have been saved by entering the command DLTJRNRCV.

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