NFS clients experience disconnections, time-outs, or performance issues due to client tuning parameters
Data ONTAP 7-Mode
Generic performance issues, NFS disconnection or timeouts may be experienced by NFS clients in relation to a mechanism called NFS Input Flow control.
If the NetApp storage controller resets an NFS TCP session, a message similar to the following is reported in the storage controller logs:
Shutting down idle connection to client (x.x.x.x) where receive side flow control has been enabled. There are X bytes in the receive buffer.
Note: This feature is completely different from Ethernet flow control which utilizes pause frames.