Ontap Select with 2 Nodes HA

[Matt99]

Can ontap select support a 2 node cluster?

I've read the best practice and it discusses single nodes, and a pair of HA nodes (4 total).  But its not clear to me if the 4 node cluster is the maximum or the minmum for HA.

A 2 node HA cluster would be sweet.

[Naveenpusuluru]

Hi @Matt99

You can set Cluster with 1 node, 2 node and 4 node also.

1. If you are using 1 node cluster then you don't need to configure intra cluster network.

2. If it is two node cluster you have configure intra cluster network (connect 2 10g ports from node1 to 2 10g ports on node2).

3. If it is beyond 2 nodes, then you need to include switches to configure intra cluster network.

note: you have to use CN1610, CN1601 or cisco 5596 , 5010 , 5020 switches for intra cluster network.

Intra cluster network : it is a private network which will be used for node communication with in the cluster.

Please let me know if you have any more questions.

[Matt99]

I'm surprised there is still a requirement for dedicated cluster switches with 4 nodes when using a software defined storage.

I haven't seen this mentioned in any of the Ontap Select design guides.  Considering the network is already virtualized it seems odd that specifc network switches are required when the Ontap select node still thinks its connected to a vSwitch.

[Naveenpusuluru]

Are you performing it on simulator or real time storage frames?.... Please go through the below link for your reference.

https://library.netapp.com/ecmdocs/ECMP1196796/html/GUID-425BDF6A-0C22-41E2-AC7E-CD34E3CC502D.html

Switched configuration

If you are setting up a two-node cluster, you can set up the cluster in either a two-node switchless configuration without cluster interconnect switches, or a switched configuration that uses the cluster interconnect switches.

[Matt99]

This link applies to physcal netapp storage...not ontap select.

This thread is about Ontap Select.  Ontap select is a virtual Netapp appliance.  There is no "switchless" config because there is no physcal nodes/controllers etc.

[JohnChampion]

Currently Select only supports 1 node (single node) or 4 node cluster configurations.  The 4-node config requires an internal network on 10Gb NICs that functions as the interconnect - but you can use the 10Gb connections for data as well if you want - just separate traffic with VLANs/portgroups on the same vSwitch.

Look for 2 node in a future release.  

I suspect a 2 node setup will still require some form of "witness" solution so probably why it's not currently available.

[SeanHatfield]

Thats about right, but we call them "mediators".  Currently each HA pair hosts the mediator mailbox disks for the other HA pair, so we need 4 nodes.  TR-4517 is a good read:

http://www.netapp.com/us/media/tr-4517.pdf

[infonet]

Any news on this 2-node only cluster? On roadmap? There are way today to provide witness if required other then putting additional cluster in place :-). Smaller vendors are doing it over NFS share or just putting small service or vm ouside the cluster like StoreVIrtual FOM. 

[bkamil]

Yep, introduced in 9.2.

From the Release Notes:

"In addition to the existing single-node and four-node clusters, you can now deploy a two-node cluster.

The following features are included to support the two-node cluster:
• High availability
A two-node cluster consists of one HA pair.

• Mediator service
ONTAP Select Deploy includes a local mediator service that connects to the nodes to monitor the cluster and help manage failures.

The ONTAP Select two-node cluster is ideal for remote and branch office deployments."