VMWare ESXi NFS Connection counts - strange behavior

Hello,

I have a very strange behavior when our ESXi Hosts using a NFS export on our Isilon cluster.

At first, some infos about our environment:

- 18x ESXi Hosts running on ESXi 6.0 U2 in one vCenter but split into mutiple "Datacenters"

- 4x Isilon Nodes (X200/210) running OneFS 7.2.1.2

- The NFS export is only used to distibute ISO and templates to all ESXi Hosts and NOT used for VMs

I created a NFS export and connected all ESXi Hosts via NFS3 to it. As the destination server for the ESXi Hosts I used the SmartConnect zone name.

In general it worked as expected. All ESXi Hosts are able to connect to the NFS export, can browse it, upload files, delete files etc.

So far, so good.

After a while I noticed a very high amount of client connections via the WebUI on the Isilon. I was a bit suprised, but some of the ESXi Hosts opened up to 50 connections. The amount varied and is not a fixed amount. When I update the view, the connection count can go up and down for no logical reason - at least to me.

A short time fix is to disable the "NFS Export Service" and then enable it again. After this all ESXi Hosts only have one connection. But this does not last for long. After some time, the connection count increased again.

Does anyone already had that issue before and could suggest a hint how to fix this? Or maybe some ideas, why this is happening?

I really appreciate any kind of help here!

best regards

Sascha