Using multiple datastreams with Exchange Database Availability Groups (DAG)s
When you back up databases in a Database Availability Group (DAG), NetBackup selects the server to back up each database according to your data source and preferred server list settings. The backup jobs are grouped by server. From your backup selections list, all of the databases that have passive copies on a given server are grouped under one snapshot job. They are then backed up by one or more child backup jobs. All of the databases that have active copies on the server are grouped under another snapshot job, followed by one or more backup jobs.
Note:
Use explicit NEW_STREAM directives in a DAG only when you are confident which servers will back up which databases.
Backup jobs are divided as follows:
When you do not enable multiple backup streams, all of the databases for a snapshot job are backed up in a single backup job.
When you enable multiple backup streams and do not specify any
NEW_STREAMdirectives, each database is backed up in its own backup job.When you enable multiple backup streams and do specify
NEW_STREAMdirectives in your policy, then NetBackup tries to group the database backups into jobs according to the placement of theNEW_STREAMdirectives in the backup selection list. The result is affected by the grouping of database backups into snapshot jobs. NetBackup separates backup jobs after any database that is followed by aNEW_STREAMdirective in the policy.