So most of this change is just always publishing data dirs when on a shared fs rather now, which only does it for auto add replicas (which requires a shared fs). Then probably adding a test. What I have been wrestling with is whether I also wanted to pull in this override the data dirs option I currently need with SOLR-6237. It's part of the dance that is currently necessary for all the replicas to agree on a shared directory. Kind of leaning against at the moment, it probably still mostly fits in SOLR-6237, but still playing around a bit to decide.