By placing multiple System i platforms in a BRMS network, you can share BRMS policies, media information, and storage locations across the network group. This allows you to manage backups across all of your systems in a consistent manner. It also optimizes media use. BRMS shares the following information across the network:
Each system in a network group receives updates to the media inventory, regardless of which network member makes the change. For example, suppose you have a network of three systems, SYSTEM01, SYSTEM02, and SYSTEM03, and that you add a media volume (A001) on SYSTEM01. BRMS conveys information about this new volume to all of the systems in the network through a process called synchronization. The system receiving synchronization updates from other systems in the network either accepts or rejects the update based on the time stamp of the updated record compared to the time stamp on the current record. Records with newer dates and times are accepted while records with older dates and times are rejected. So the dates and times of the systems within a BRMS network become very important.
Ideally, a BRMS network performs best if all systems in the network are in the save time zone and are running with dates and times which are consistent across all systems. However, BRMS allows for time differences up to 24 hours between these systems in the event the systems are in different time zones.
Care needs to be taken to avoid systems in a BRMS network which have a time difference that is more than 24 hours resulting in these systems having different dates. BRMS uses dates to determine expiration of media, when volumes need to be moved, and whether synchronization updates are applied.
If business reasons dictate a need to have systems in the network with a greater time difference than 24 hours, you must set up BRMS on these systems as follows:
The system that has a different time and date compared to the current time and date, need to use volumes in a no shared media class. This is necessary to ensure any saves to media from this system are not overwritten by other systems or this system does not overwrite the saves on media used by the other systems.
Media movement on this system will need to be run by control group, move policy or system name as volumes may not move as otherwise expected.
The recommended approach is to avoid time differences between systems that exceed 24 hours.