Yeah I know the configuration of my file library is far from ideal, but the issue is I am severely low on IOPS on my backup storage. The result is if a phase 2 job (disk to tape) is kicked off while another library drive is still writing, the tapedrive won't get into streaming anymore because my file library is not delivering. Therefore I have only three virtual tapedrives and mainly use only one for both reading and writing, that way the running job always has the full 'power' of my file library. The only jobs where that really matters are the ones writing to tape. We have only a small company with limited storage requirements and even less money in these days to invest. Therefore I want to stick to this method for now.
However, I still think somethings wrong. If I do a default restore of all data in the machine to a temp-location, it finishes in a few minutes, only sending the actual data over the network. Even if the 20GB of data I need are stacked inside 200+GB of other data, which is very unlikely in the first place, I'd expect to see only the 20GB on my network, while the rest is 'dropped' in my backup server locally.
In addition I also have a B2D (softwarebased) store, which doesn't do concurrency anyway and it behaves the same, also a huge amount of network data, a factor 10+ compared to the actual data that is to be restored.