Add support for NFS profiler

[johnugeorge]

Since files are in closed category, we need to add profiler support for NFS. Currently, we have IOSTAT which won't work for NFS.

[zhenghh04]

@hariharan-devarajan you have better knowledge on the profiler. Any thoughts on this?

[hariharan-devarajan]

Darshan and recorder should work on nfs as the interception happens on the application and VFS level of the file system. IOStat is a system level profiler which will be hard to work with at a distributed level.

If you want metrics from system, I believe ldms work with lustre file system to capture system level IO counters.

[tonycasanova]

Has Netdata been evaluated for metrics collection in the VM under test for metrics? It has a RAM mode to help make the metrics collection lighter on the CPU and I believe it can collect metrics from standard disks and nfs. It is easy to install.
https://blog.netdata.cloud/how-to-monitor-your-disks-and-filesystems-now-also-with-ebpf/