volume_driver= cinder.volume.drivers.netapp.common.NetAppDriver is the correct setting that should be used in Havana and subsequent releases. When using the common.NetApp driver, be sure to set the netapp_storage_family=ontap_7mode if your controller is operating in 7-Mode.
The Unexpected error:<urlopen error [Errno 111] ECONNREFUSED> error indicates that there is a network connectivity issue between the Cinder node and your simulator instance. The netapp_server_hostname should be the IP address of the cluster management interface, and be sure that the IP address in the shares.conf file corresponds to the Data LIF from the FlexVol NFS export.
After verifying that you're using the correct IP addresses, please ensure you are able to ping them from the Cinder node, as well as successfully establish a TCP connection to the mgmt interface (e.g. "telnet 192.168.0.131 80").
Re: Configure Cinder(Havana) to create VM datastore on NetApp Simulator 8.2(7-mode)
Bob is correct, cinder.volume.drivers.netapp.common.NetAppDriver is the correct volume_driver to use starting in Havana. I have seen the ECONNREFUSED error as well when there is a protocol mismatch. Make sure when using the common driver that you have the following 2 lines in your driver config:
netapp_storage_family = ontap_7mode
netapp_storage_protocol = nfs
My guess though, is that since the common driver defaults to clustered-mode, you are getting the ECONNREFUSED because the driver is trying to talk to a 7-mode vsim as though it were a cDOT vsim.