This statistic shows NFSv[2-4] operations/sec (NFS IOPS) requested by clients to the appliance. Supported NFS versions are: NFSv2, NFSv3, NFSv4.0 and NFSv4.1. Various breakdowns are available to show the client, filename, and latency of the NFS I/O.
NFSv[2-4] 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. Client and especially filename breakdowns can be very expensive in terms of storage and execution overhead. Therefore, it is not recommended to permanently enable these breakdowns on a busy production appliance.
These breakdowns can be combined to produce powerful statistics. For example:
"Protocol: NFSv3 operations per second of type read broken down by latency" (to examine latency for reads only)
"Protocol: NFSv3 operations per second for file '/export/fs4/10ga' broken down by offset" (to examine file access pattern for a particular file)
"Protocol: NFSv3 operations per second for client hostname.example.com broken down by filename" (to view which files a particular client is accessing)
See Network: Device Bytes for a measure of network throughput caused by the NFS activity; Cache: ARC Accesses to learn how well an NFS read workload is returning from cache; and Disk: I/O Operations for the back-end disk I/O caused.