We have perofrmance issue.
The NFS datastore has <5 ms latency on the filer, but >80ms on VM guest as shown in vCenter. To me, the performance issue is not caused by the filer.
But, what steps should I take to investiage and find out the root cause, either on the filer side, VM guest, or both?
You have mentioned it is NFS export. The issue migt be with network. Please run packet traces between filer and vmware hosts and submit them to NetApp support. They will let you know exact rootcause of the issue.