With combine source data stream, it allows for better optimization in Tape Media utilization as you are distributing the Secondary Copy data across two Tape Medium
However because we are spreading the data across the two Media, and base on the rules of Aux Copy - During an Auxiliary Copy operation, the data is copied in the following sequence:
- A media which contains oldest backup job is copied first.
- When all the data from this media is copied, the other media with oldest backup job is selected for the copy from a drive pool.
- When all the media from the drive pool are copied, the oldest media from the other drive pool is selected for the copy.
- When all the media from a library are copied, the oldest media from the other library is selected for the copy.
- When all media associated with a MediaAgent are copied, the oldest media from the other MediaAgent is selected for the copy.
Not every stream will be even.
Additionally because Tape Media is sequential medium, the read process to verify the data could be slower due to the overhead to determine where the exact block is written to for the specific backup job that is Aux Copied to Tape.
If you attempt to do combine source stream to a single tape, and Aux Copy one backup to Tape, I would believe the verification will be faster