Multistreaming helps to Multistreaming sends data from a single client to multiple tape drives at the same time. It is advantegeous wherein the client the client is a high end client (throughput higher that the tape drives can handle). Multistreaming allows multiple backups (streams) of a single client to occur simultaneously to multiple tape drives.
During multistream backups, the plug-in splits the Backup Selection Set is into smaller selection groups and uses separate child processes to perform parallel backups of these selection groups.
You can use the multistream options to do the following:
•Back up multiple volumes, network shares, and mount points simultaneously
•Back up a single volume using multiple parallel streams
While configuring the multistreaming option for backing up multiple mount points if you don't select the option :Always use a new stream when crossing a mount point backup will run a single stream only