The Maximum concurrent jobs setting specifies the maximum number of jobs that NetBackup can send to a disk storage unit at one time. (Default: one job. The job count can range from 0 to 256.) This setting corresponds to the Maximum concurrent write drives setting for a Media Manager storage unit.

If three backup jobs are ready to be sent to the storage unit and Maximum concurrent jobs is set to two, the first two jobs start and the third job waits. If a job contains multiple copies, each copy applies toward the Maximum concurrent jobs count.

The Maximum concurrent jobs setting can be used to balance the load between disk storage units. A higher value (more concurrent jobs) means that the disk may be busier than if the value was set for fewer jobs.

The media server load balancing logic considers all storage units and all activity. A storage unit can indicate three media servers. If Maximum concurrent jobs is set to three and two of the media servers are busy or down, the third media server is assigned all three jobs.

The Maximum concurrent jobs setting depends on the available disk space and the server's ability to run multiple backup processes. Where disk pools are used, the setting also depends on the number of media servers in the storage unit.

If multiple storage units reference the same disk pool, the number of concurrent jobs that can access the pool is the sum of the Maximum concurrent jobs settings on all of the disk storage units. The setting applies to the storage unit and not to the disk pool. Therefore, the job load is automatically spread across the media servers that the storage unit configuration indicates.