This statistic shows NFSv4 operations/sec (NFS IOPS) requested by clients to the appliance. Various useful breakdowns are available: to show the client, filename and latency of the NFS I/O.
See Protocol: NFSv3 operations for an example of a similar statistic with similar breakdowns.
NFS operations/sec can be used as an indication of NFS load, and can be viewed on the dashboard.
Use the latency breakdown when investigating NFS performance issues, especially to quantify the magnitude of the issue. This measures the I/O latency component for which the appliance is responsible for, and displays it as a heat map so that the overall latency pattern can be seen, along with outliers. If the NFS latency is high, drill down further on latency to identify the type of operation and filename for the high latency, and, check other statistics for both CPU and Disk load to investigate why the appliance is slow to respond; if latency is low, the appliance is performing quickly, and any performance issues experienced on the client are more likely to be caused by other factors in the environment: such as the network infrastructure, and CPU load on the client itself.
The best way to improve performance is to eliminate unnecessary work, which may be identified through the client and filename breakdowns, and the filename hierarchy view. It's best to enable these breakdowns for short periods only: the by-filename breakdown can be one of the most expensive in terms of storage and execution overhead, and may not be suitable to leave enabled permanently on a busy production server.
These breakdowns can be combined to produce powerful statistics. For example:
"Protocol: NFSv4 operations per second of type read broken down by latency" (to examine latency for reads only)
"Protocol: NFSv4 operations per second for file '/export/fs4/10ga' broken down by offset" (to examine file access pattern for a particular file)
"Protocol: NFSv4 operations per second for client 'phobos.sf.fishpong.com' broken down by file name" (to view what files a particular client is accessing)
See Network: Device bytes for a measure of network throughput caused by the NFS activity; Cache: ARC accesses broken down by hit/miss to see how well an NFS read workload is returning from cache; and Disk: I/O operations for the back-end disk I/O caused.