This option applies only to backups that use VCB.

When NetBackup backs up a virtual machine, it copies the virtual machine .vmdk files from the VMware datastore to the VMware backup host. Note that NetBackup can copy a large vmdk file to the VMware backup host as 2GB files instead of as a larger file. Sending a large vmdk file in smaller (2GB) units can improve transfer speed.

This option is disabled by default: the vmdk file is transferred to the VMware backup host in 2GB chunks.

Enabled means that the vmdk file is transferred to the VMware backup host as a single file, regardless of how large the vmdk file is. In some cases, transferring a very large vmdk file may result in a slower transfer speed.