If you are running concurrent backups, it is strongly suggested not to save media information with either backup. It is recommended you run the Save Media Information (SAVMEDIBRM) command after the concurrent backup control groups have completed.
In a concurrent save operation, you send multiple save jobs to multiple tapes devices to process at the same time (concurrently). For example, using a concurrent backup strategy, you might send one library or group of libraries to one tape device, and another set of libraries to a different tape device. Concurrent backup support also allows multiple SAVDLO operations from the same auxiliary storage pool (ASP). Anything that you can save concurrently, you can restore concurrently, thereby reducing your downtime after a system failure occurs when recovering multiple libraries or objects at the same time.
You set up the concurrent operation by specifying different device names inside the individual control groups or save commands that you want BRMS to process concurrently. You must try to evenly balance the contents of each job so that each tape device completes at about the same time. This results in more efficient use of your tape resources. If you want to use *INCR or *CUML saves, keep in mind that processing time for each save varies by content size.