/local/rvm/gems/ruby-1.9.2-p320/gems/activerecord-sqlserver-adapter-3.2.12/lib/active_record/connection_adapters/sqlserver_adapter.rb:455:in `initialize\': IM002 (0)
just a tip, in my case was not possible with Driver = FreeTDS and both variables "servername" and "server" in odbc.ini. I let only "server = ip" and "Driver = /usr/lib/i386-linux-gnu/odbc/libtdsodbc.so", worked fine.