FYI, the only "stackers" we officially support are the Quantum 4700 and Breece Hill Q2.15.
Well, the 4700 is end-of-life, and is no longer available. So that leaves one possibility for those of us who'd like to feel assured of a working backup solution?
http://www.atlp.com/products/dlt4500/dlt4500.html
We have had issues with timing on other tape stackers and have made recent changes to Data ONTAP that should cope with these variations, but we have no roadmap to "certify" a bunch more stackers.
Any hint on what I could expect from a Qualstar 6110 (DLT4000) versus an Exabyte EXB/18D-4TD?