Toasters,
We have ethernet flow control set to full on our NetApp's 10g interfaces. The FEX ports to which our 10g interfaces are connected also have flow control TX/RX enabled. I realize enabling flow control is against best practices.
I am trying to determine if we are seeing an excessive number of flow control frames. We received over 12,000 PAUSE frames from the FEX within a 10 minute period which sounds excessive to me. Can anybody confirm that 12,000 is an excessive number of PAUSE frames that would likely result in connectivity issues?
Here are statistics for one of our 10g interfaces during a recent 10 minute interval. Notice that the NetApp is receiving PAUSE frames (RECEIVE-Xoff) from the FEX and never transmitting (TRANSMIT-Xoff).
RECEIVE Jabber: 0 | Bus overruns: 0 | Xon: 12412 Xoff: 12412 | Jumbo: 0 TRANSMIT Queue overflows: 0 | No buffers: 0 | Xon: 0 Xoff: 0 | Jumbo: 0 | TSO non-TCP drop: 0
What I see is the FEX telling the NetApp to slow down. I just dont know if the FEX is slowing down the NetApp enough that it would cause problems.
Have a great day, Phil