topic Re: Two-chassis, switchless cluster w/ FAS 3240 in ONTAP Hardware

Two-chassis, switchless cluster w/ FAS 3240

schmitz_peter — Wed, 04 Jun 2025 13:16:44 GMT

Hi all,

I am trying to set up a two-node, switchless cluster with two FAS 3240. I wiped everything and connected c0a and c0b ports for HA interconnect.

After the node setup returns I try a "cluster create" on node1, which seems fine, but a "cluster join" on the second node bails out, because the only (system-)configured clusterport ist e1a (on both nodes, by the way.)

What gives? I can neither see nor configure the dedicated cluster ports c0a and c0b.

How can I set up a switchless cluster with those two!?

Thanks for any insights

Peter, wiping again...

Re: Two-chassis, switchless cluster w/ FAS 3240

Damien_Queen — Wed, 26 Sep 2018 18:10:41 GMT

c0x ports dedicated only for HA (in your case you do not need them since your controllers in the same chassis & using internal HA interconnect build in the chassis). c0x HA ports can be used in both cDOT & 7-mode.

What you need is cluster 10Gbps ports in addition to c0x (which remain unused in your case). Cluster ports can be used only in cDOT.

Do not mix up HA interconnect ports & Cluster Ports; they are separate entities dedicated for different purposes.

You cannot use c0x ports as cDOT cluster ports even if they are left unused.

3200 systems MUST have additional PCI 10Gbps card with two ports on each node dedicated to cluster connection in cDOT.

Note: not all 10Gps cards are supported & can handle cluster interconnect, take a look on HWU for supported cards for cDOT cluster interconnect.

Re: Two-chassis, switchless cluster w/ FAS 3240

schmitz_peter — Wed, 26 Sep 2018 17:54:38 GMT

Hi Damie,

thanks for the quick answer.

To clarify, this is not a single-chassis system. I have two separate chassis with IOXM boards. That's why I tried to use c0a and c0b for cluster interconnect in the first place, which didn't work at all. I created a cluster on node 1 and tried to join the second node, which didn't work.

So, if I understand correctly, to run switchless I'll have to cable two more 10Gps ports from node 1 to node 2 as cluster ports, right?

Thanks again

Peter

Re: Two-chassis, switchless cluster w/ FAS 3240

SpindleNinja — Wed, 26 Sep 2018 18:01:29 GMT

That's correct, you basically have to use (or add) the 10G cards in the expantion slots for the cluster connections.

Re: Two-chassis, switchless cluster w/ FAS 3240

Damien_Queen — Wed, 26 Sep 2018 18:12:15 GMT

In this case, you have to use c0x ports, but they will be used only for HA (whether in 7-mode or cDOT).

Again, c0x only for HA, not for cDOT clusterization.

For cluster interconnect for cDOT with 3240 you have to install additional PCI card with 10Gbps ports and use ports from that card as the cluster interconnect ports. Without that cards switch-less or switched cDOT cluster will not be going to work. Therefore you will not be able to join the nodes.

Re: Two-chassis, switchless cluster w/ FAS 3240

schmitz_peter — Wed, 26 Sep 2018 18:07:48 GMT

Thanks guys, will try that tomorrow. I have several 10Gps ports I could use.

Great!

Will report back tomorrow.

Peter

Re: Two-chassis, switchless cluster w/ FAS 3240

Damien_Queen — Wed, 26 Sep 2018 18:10:17 GMT

Check HWU for supported 10Gbps cards which can be used for the cluster interconnect with your 3240 system.

Re: Two-chassis, switchless cluster w/ FAS 3240

schmitz_peter — Thu, 27 Sep 2018 07:24:29 GMT

Morning. Two cables and the cluster is up and running.

Thanks a lot for your help!

Peter