Just out of curiosity, what is the output of "network interface show -vserver pnfs-svm"
The answer might lie there. 
I doubt it is a VLAN issue and more a network design issue.

I found this:

https://mysupport.netapp.com/site/article?lang=en&page=%2FAdvice_and_Troubleshooting%2FData_Storage_Software%2FONTAP_OS%2FNFSv4.1_client_Read%2F%2FWrite_operation_may_be_slow_or_hang_when_pNFS_is_enabled_on_the_SVM&type=reference

Issue

  • When NFS client attempts to Read/Write to the SVM with pNFS enabled, the operation hangs, with "nfs: [LIF address / hostname] server not responding" in /var/log/messages.

Cause

  • This issue occurs in situations where pNFS is enabled on an SVM and there are LIFs created in different subnets, which are non-routable by the client
  • Data ONTAP may provide any LIF which belong's to the same SVM as the referral to a client
  • The Read/Write operation hangs because the data LIF IP is not reachable by the client

Solution

  • Make sure clients can reach all data LIFs of the SVM

-or-

  • Disable support for pNFS on the SVM

::> nfs modify -v4.1-pnfs disabled



--tmac

Tim McCarthy, Principal Consultant

Proud Member of the #NetAppATeam

I Blog at TMACsRack




On Mon, Aug 16, 2021 at 9:16 AM Florian Schmid via Toasters <toasters@teaparty.net> wrote:



---------- Forwarded message ----------
From: Florian Schmid <fschmid@ubimet.com>
To: toasters <toasters@teaparty.net>
Cc: 
Bcc: 
Date: Mon, 16 Aug 2021 13:13:15 +0000 (UTC)
Subject: pNFS not working on vserver when several lifs with different Vlans available
Hi,

I had a very strange incident some weeks ago.

We are on 9.7 branch.

In one of our vServers, where we had NFSv4 and 4.1 enabled, clients with NFSv4.1 and pNFS where unable to read or write data.
Directory listing was possible.

On the vServer, we have several different Vlans and each Vlans has an interface for each node there. Our storage network is completely switched, so no routing between Vlans possible.

After creating a NetApp case, they told me, that pNFS doesn't handle Vlans and the client will get any IP on that node, even when the IP is from a different Vlan and therefor not accessible from the client.

Is this really the case? Is the pNFS process really not Vlan aware and sends any IP from that node where volume is located, even when the IP is in a different network than the client IP?

As suggested from NetApp, I have disabled pNFS and now everything is working.

What is your experience here?
Is anybody using pNFS with NetApp and if yes, do you only have one network in your vServer or is the client able to access all IPs there through different Vlans?

I'm curious about your answers.

Best regards
Florian Schmid




---------- Forwarded message ----------
From: Florian Schmid via Toasters <toasters@teaparty.net>
To: toasters <toasters@teaparty.net>
Cc: 
Bcc: 
Date: Mon, 16 Aug 2021 14:13:20 +0100
Subject: 
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