Storage Accelerator can be used on a source MediaAgent to directly send the backup data to an auxiliary copy. (Without the Storage Accelerator, source MediaAgent send the backup data to the destination MediaAgent first, and then the destination MediaAgent writes the data to the cloud storage library.)
Unlike backups where Storage Accelerator package should be installed on client, Storage Accelerator for auxiliary copy is enabled by default and does not require any special package to be installed.
The data flow diagram for the storage accelerator feature is given below:
