topic Re: Ontap 9.x simulator support pNFS MDS and DS nodes or just MDS? in Simulator Discussions

Ontap 9.x simulator support pNFS MDS and DS nodes or just MDS?

RedHat — Wed, 04 Jun 2025 13:31:51 GMT

Hi,

I am wondering whether the simulator supports pNFS with both MDS and DS nodes, or just an MDS? I am thinking maybe it does not support DS nodes since that is similar to clustering but wanted to confirm.

Thanks.

Dave Wysochanski

dwysocha@redhat.com

Re: Ontap 9.x simulator support pNFS MDS and DS nodes or just MDS?

AlexDawson — Tue, 10 Jul 2018 04:50:02 GMT

Hi there!

Our public simulator is just a capacity limited version of our regular controller environment, so it supports essentially everything that our physical systems do (with the exclusion of fibre channel and nvmeof). We have a whitepaper on pNFS implementation available at https://www.netapp.com/us/media/tr-4063.pdf

I've dealt with NFS for many many years, but not pNFS. Based on my reading of that paper, our systems act as both metadata (MDS) and data servers (DS). Even if run in a single controller environment, all of our services still run in a "cluster" implementation, so I believe a single node simulator will still run those personalities. There are instructions available for expanding it to a dual-single node cluster (vs a regular HA pair), if it comes to that.

Hope this helps! Please feel free to post any follow up questions.

Re: Ontap 9.x simulator support pNFS MDS and DS nodes or just MDS?

RedHat — Tue, 10 Jul 2018 14:49:42 GMT

Thanks! Yes I think it should work as long as I mount the different IP address from the node on which the volume is located. Then I should get the MDS as one node and the DS as the other.

Re: Ontap 9.x simulator support pNFS MDS and DS nodes or just MDS?

AlexDawson — Wed, 11 Jul 2018 01:55:36 GMT

In our object heirarchy, logical interfaces like IPs used for NFS belong to the storage virtual machine (SVM) and not nodes, but if you do want to test "indirect" access being referred correctly, yes, you would need to have a two node cluster and have the LIF used for access on a different node.