Adding 2 more nodes on cDOT 8.2 cluster on the existing HA enviornment.

[KIIKANZAVANNA]

Hi, 

We have currently 2 v3240 with cDOT ver 8.2 clustered as below. 

We are adding 2 more v3240 and I need the exact steps of adding them on the existing cluster. 

I would think that I have to disable the HA cluster and then add them on the cluster but I need more information. 

Also I can't find any official document on how adding 3rd node with cabling info.

c-netapp::cluster> cluster ha show
High Availability Configured: true

Please advise. 

Many thanks and appreciated. 

[ekashpureff]

KIIKANZAVANNA  -

Listing the 'exact steps' to add your new nodes could fill a book !

The additional HA pair needs to be cabled in to cluster, data, and mgt. networks.

3rd and fourth node - they're a pair.

You do a 'cluster join' command to join the new nodes to the cluster.

Yes, you want to disable '2 node HA' on the cluster before the join:

cluster ha modify –configured false

This doesn't disab;e the storage failaover (sfo) with the existing pair.

It does change the cluster quorum rules.

I hope this response has been helpful to you.

At your service,

Eugene E. Kashpureff, Sr.
Independent NetApp Consultant http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, IT Learning Solutions http://sg.itls.asia/netapp
(P.S. I appreciate 'kudos' on any helpful posts.)

[aborzenkov]

Cluster Expansion Express Guide provides detailed step by step procedure how to add new nodes to existing cluster including references how to migrate from switchless to switched cluster.

[KIIKANZAVANNA]

Hi,
Thanks both of you for the info and docs provided, really appreciated. I've read some 8.2.2 Clustered Documentations already.
I will create a HA pair on the new filers with new SAS disks and join those 2 new filers to the cluster as a front end, but the back end with disks will be on its own HA cluster only.
(referred to the config on
https://library.netapp.com/ecm/ecm_download_file/ECMP1367947 (page 13)).
"HA pairs are components of the cluster, and both nodes in the HA pair are connected to other nodes
in the cluster through the data and cluster networks. But only the nodes in the HA pair can takeover
each other's storage."

I'm still slightly confused if I must disable a HA on the existing node at first and then join each filer to the cluster or not.
My goal is to join the new filers to the cluster so that the volume migration will go easily rather than using a snapmirror which can be slower.
Please let me know

Many thanks

Warm regards

[aborzenkov · Accepted solution]

Yes, documentation is rather confusing as it mixes "HA" to mean "HA pair" (actually storage failover) and "HA mode" (special epsilon-less mode for two node cluster). You have to disable HA mode. It may be done automatically by wizard when you join the third node in 8.3 - at least, express guide does not explicitly mentions it. But in any case you should check and verify that it is disabled.

SnapMirror won't be really slower, as volume migration between HA pairs will still be performed over 10G ethernet. But volume move in a cluster will be completely transparent to clients - there won't be any cut-over phase comparing with SM.