For our use case, the disk portion doesn't live on the Mac Pros (we have Linux systems that act as storage servers). We toyed with open shelf type solutions th

For our use case, the disk portion doesn't live on the Mac Pros (we have Linux systems that act as storage servers). We toyed with open shelf type solutions that would let us mount the systems front-to-back, but as you noted, anything above 2 Mac Pros across won't fit in a 19" rack. We also thought about mounting 23" rails in our standard cabinet, but ultimately settled on this chassis and orientation. One of our early design ideas: https://www.dropbox.com/s/15u19aivay4hfiu/2014-01-13%2017.14.50.jpg?dl=0 https://www.dropbox.com/s/15u19aivay4hfiu/2014-01-13%2017.14...