NFS 4.1 multipathing

[FrankWest]

Hi,

during the RC stage of Ontap 9.12.1 it was mentioned that it finally supported NFS 4.1 multipathing. However, now that 9.12.1 has been released I can’t find NFS 4.1 multipathing support in the release notes.

Am I missing something?

[heightsnj]

All our client connections, mostly NFS volumes or NFS datastores, a handful CIFS are running on the top of 2x100GbE LACP setup on each node within the cluster 

Both "nconnect" and "session trunking" should address issues caused by networking bottleneck, upon my understanding. We don't have such issues. Even though we had,  "neconnect" would be the first thing we should try, because it is easy to set up, and can provide multiple TCP sessions over a LIF, but essentially all over the LACP. 

We don't have plan or wouldn't set up extra NIC's or LACP group's, setting up session trunking and then making sure all failover/takeback would work as expected is not so straightforward, and plus, session trunking only work on a single node, essentially over the LACP as well, same as "nconnect".  

Weighing in on those considerations, it is good to know such option, but we wouldn't really benefits too much from "session trunking" in our case, correct? 
 

[billy_mcwaggins]

Hi @heightsnj ,

Reference: https://docs.netapp.com/us-en/ontap/nfs-trunking/#how-to-use-trunking 

Difference between NFS trunking and nconnect

Beginning with ONTAP 9.8, nconnect functionality is available by default when NFSv4.1 is enabled. On nconnect-capable clients, a single NFS mount can have multiple TCP connections (up to 16) over a single LIF.

In contrast, trunking is multipathing functionality, which provides multiple TCP connections over multiple LIFs. If you have the ability to employ additional NICs in your environment, trunking provides increased parallelism and performance beyond the capability of nconnect.

[paul_stejskal]

You're getting your layers mixed up. LACP is layers 2 (3 if using IP based distribution). nConnect functions on layer 4. NFS multiple streams are more layer 3-layer 5-7. Each has a different function.

nConnect combines TCP streams to parallelize the same traffic from/to client IP to/from server IP on the same IP set (same ports).

LACP combines multiple ethernet ports into a single logical port, which can parallelize multiple connections from multiple clients across a single logical port.

NFS Multipathing can scale across ports.

Using nConnect with LACP might be enough to use both ports depending on your switch and ONTAP LACP balancing configurations.