NFS fails when using custom TCP/IP stack

Products

• VMware
• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• NFS traffic goes through the default stack even though default stack was created with a dedicated subnet.
• NFS traffic fails to use custom TCP/IP stack.
• Unable to add new NFS mounts with custom TCP/IP stack.

Environment

VMware vSphere ESXi 6.x
VMware vSphere ESXi 7.x

Resolution

To resolve this issue, specify the Custom Netstack in NFS services for NFS to use custom TCP/IP stack.

To specify the Custom Netstack in NFS services:

1. Run this command to create the netstack:

# localcli network ip netstack add --netstack=nfs

2. Run this command to unmount any existing NFS shares:

# localcli storage nfs remove -v volume-name

3. Run this command to stop the NFS service:

# /etc/init.d/nfsgssd stop

4. Run this command to unload the NFS modules:

# vmkload_mod -u nfs41client
# vmkload_mod -u nfsclient
# vmkload_mod -u sunrpc

5. Run this command to configure the sunrpc module with the specified netstack:

# localcli system module parameters set -m sunrpc -p netstackName=nfs

6. Run this command to reload the NFS modules:

# localcli system module load -m sunrpc
# localcli system module load -m nfsclient
# localcli system module load -m nfs41client

7. Run this command to restart the NFS service:

# /etc/init.d/nfsgssd start

8. Run this command to remount the NFS shares:

# localcli storage nfs add -v <Datastore_Name> -H <NFS_Server_address> -s </share_mount_point>

Example:

localcli storage nfs add -v NFS_Datastore -H xxx.xxx.xxx.xxx -s /NFS_share/esx_nfs01

Additional Information

Custom TCP/IP stack for NFS has been deprecated from vSphere 8.0 and the workaround to use Default TCP/IP stack to fix the issue.

Additional reference article:

Remounting a disconnected NFS datastore from the ESXi command line