A good place to begin is the OS/400 backup and Recovery manual found at the IBM online publications Web site. If you are thinking of using journaling for commitment control, you can also find manuals specific to your programming language of choice on the same web-site. The following is a very brief overview of journaling. When you setup journaling, you first create a journal receiver and then the journal. The journal receiver contains record level and file level transaction information about the files being journaled as well as some standard system type information about each transaction (User, date, time, transaction type, etc.) The transaction information in the journal receiver contains record level information about records that were updated, changed, deleted, etc. and has the potential to store the before and after images of the records updated. You can use commands such as RMVJRNCHG to remove erroneous file updates caused by a program or you can display the journal data and use it for debugging purposes to see what program caused an erroneous file update. I just scratched the surface about things you can do with journaling. It's a powerful and flexible tool but one that also can consume huge quantities of disk space if you are not careful. A few basic commands to get you started are CRTJRNRCV, CRTJRN, STRJRNPF, DSPJRN, WRKJRNA, CHGJRN.
This was first published in April 2001