NFSv4.1 session trunking / multipath support ( not nconnect or pNFS )

[Mauricio Silveira]

I dug google, truenas forums and documentation but found no "clear" statement about the current support for NFS session trunking in both Scale and Core.

No, I'm not confusing it with pNFS or nconnect.

My research included a good bit of search into FreeBSD 12.2 and 13 too.

by trunking, I really mean this from the nfsv4.1 RFC:
I mean this: https://datatracker.ietf.org/doc/html/rfc5661#section-2.10.5 .

I don't have access to my Scale box right now, but... from the RFC, I wonder if both FreeBSD and Linux kernel in the TrueNAS versions really support it.

I'm familiar with iSCSI multipathing, I've always use it on an ESXi deploy with multiple vmkS/VLANs. The truth is that I neglected the multiple server ips option for NFSv4.1 in vCenter because I always used NFSv3.

Examples:

Best Practices For Running NFS with VMware vSphere | VMware

This guide provides an overview of the considerations, best practices for deployment of VMware vSphere on NFS based storage and troubleshooting tips and tricks.

core.vmware.com

NFS & iSCSI Multipathing in vSphere | VMware

Path selection Currently, NFS 4.1 client selects the paths in a Round-Robin fashion.

core.vmware.com

It's a bit confusing and interchangeably used the terms trunking, parallel, multiple, multipath in NFS discussions.

In linux client you have options nconnect=x (Not about multipath ) and max_connect=x ( This seems to fine tune multipath )

BTW, nconnect support is on its way in ESXi8: https://kb.vmware.com/s/article/91497

I was about to give up on writing this post, but I think this discussion might help others.

Thanks!