Thanks for the clarification. That the PODs were on rails was never made clear to me. Still, I count that as "physically removing a 4u rackmount storage pod." Those suckers cannot be light. 10 seconds sounds rather fast. I don't imagine you could do it that fast for any of the upper pods.

While I don't recommend them outright, we settled on 3U boxes from SuperMicro. http://www.supermicro.com/products/chassis/3u/837/sc837e26-r...

We somewhat affectionately dubbed them "mullets" as in business in the front, party in the rear.

They make 4U devices as well. Cost was about $1000. We added LSI Megaraid 9280 controllers, about another $1500 and ran min-SAS back to a controller node responsible for 4 JBODs.