Hi,
I agree. I used BATCHSIZE option in some policies in my environment, and I used at top of backup scripts, just as Marianne, said...I even used this same technote.
Performance tuning for NetBackup for Microsoft SQL Server backups - https://www.veritas.com/support/en_US/article.TECH33423
BATCHSIZE is the number of databases NetBackup will attempt to back up simultaneously. If, for example, there are 50 databases on the SQL server, and the BATCHSIZE variable is set to 5, when the backup initiates, the NetBackup SQL extension will grab the first five databases, and start running the backup of those five databases. Depending on the configuration of the media server and the storage units, the backup will use five drives. See the technote "How to back up multiple Microsoft SQL Databases in parallel using more than 1 tape drive" in the Related Documents section below for more information on how to use multiple drives for this type of operation.In general, if SQL server has only a few large databases, use of stripes will improve performance. If the server has numerous smaller databases, Batchsize will improve performance. Please note it is possible to use both stripes and batchsize at the same time, however, be careful not to overwhelm the system resources.
Regards,
Thiago