Hi..
Depending on your setup you might also want to check Flow Control settings on connected pSwitches and host pNICS.. According to NetApp flow control should now be disabled on modern network gear...
From: http://media.netapp.com/documents/tr-3749.pdf
"For modern network equipment, especially 10GbE
equipment, NetApp recommends turning off flow control and allowing congestion management to be
performed higher in the network stack. For older equipment, typically GbE with smaller buffers and
weaker buffer management, NetApp recommends configuring the endpoints, ESX servers, and NetApp
arrays with the flow control set to "send."
/Rubeck