This topic provides information about how to start journaling for all object types.
After you have created the journal and journal receiver, you can start journaling. When journaling has been started for an object, the system writes journal entries for all changes to the object.
The start journal command must obtain an exclusive lock on the object. However, for database physical files and integrated file system objects, you can start journaling even if an object is open. The recommended procedure for starting journaling is:
- Start journaling the object.
- Save the object. If the object is open for changing, this will be a save-while-active type save.
If you are not using the save-while-active function, it is highly recommended that you update the history for the object when you save it so that processing for applying and removing journaled changes will have the best information for verification. If you saved the object using the SAV command, the default value is to not preserve the update history. Therefore, change the UPDHST value to something other than *NO.
For the other save related commands, the default value is to preserve the update history. When using save-while-active, updating the history for the object is not needed for verification when applying and removing journaled changes. In this case, information is saved on media with the object, and restored when the object is restored. This extra information provides the last save information for applying and removing journaled changes.
Normally, only the definition
of a data queue is saved, not its contents. To save the contents of the queue
as well, one must specify QDTA(*DTAQ) on the save commands.
The maximum number of objects that can be associated with one journal
is either 250,000 or 10,000,000. The option of setting the journal object
limit to 10,000,000 simplifies journaling because there are fewer journals
to manage, but allows for less parallelism during IPL and disaster recovery.
You can also have all objects created within a subdirectory start journaling
automatically without having to be broken up when you reach the 250,000 limit.
The value *MAX10M can only be specified for the Journal Object Limit (JRNOBJLMT)
parameter if the Receiver Size Option (RCVSIZOPT) parameter has one of the
*MAXOPT values specified or if RCVSIZOPT is *SYSDFT.
The following links provide instructions to start journaling for each object type: