5D won't connect through Thunderbolt


We are using Mac OS X Server 10.6.8 for file sharing, Its not connecting when I connect our drobo 5D to this server through Thunderbolt. It is working through USB.
I need to connect drobo 5D through thunderbolt for file sharing. I can’t connect through USB because we are using Gigabit Ethernet (will feel the bottle necking)

hi do you know if any other thunderbolt devices have been working (or are still working) with filesharing on that mac server?
(am just wondering in case we can try to pinpoint things a bit further?)