New Cluster Nodes Not Showing in NetApp DSM for MPIO

[TMADOCTHOMAS]

I've just added two new nodes to our production cluster. I've added two new iSCSI LIFs on the nodes and added those LIFs to the port group. I've used SnapDrive to add connections to the two new iSCSI LIFs on the first of many Windows hosts. After doing this, I checked the Data OnTAP DSM for MPIO software to be sure it was showing 4 nodes per LUN. It is not. It is still just showing two paths. Any ideas as to what I am missing?

[TMADOCTHOMAS]

Bob, thank you!

After this whole discussion, I still believe I'd like to play it safe and go ahead and add the reporting nodes for 3 and 4 before migrating the LUNs. To do that, i believe the following commands would work. Does this appear correct?

lun mapping add-reporting-nodes -vserver <vserver> -path <LUN_path> -igroup <Igroup_Name> -destination-aggregate <aggregate_on_node_3>

lun mapping add-reporting-nodes -vserver <vserver> -path <LUN_path> -igroup <Igroup_Name> -destination-aggregate <aggregate_on_node_4>

For the <LUN_path>, do you happen to know how the wildcard feature works. Specifically:

Can I do this: /vol/<servername>*

Instead of this: /vol/<servername>*/<servername>*.lun

[bobshouseofcards]

Those commands are the right form but you only run one of them per volume to be moved.  So you would not run both commands for all aggregates.  An aggregate exists within a node HA pair construct.  It is owned by one node, but will failover to the other node.  Hence, when you add the nodes associated with a destination aggregate, you are adding both nodes in the HA pair since either one could own the aggregate.

And the wildcarding works as you'd expect.  * matches everything.

Bob Greenwald

Senior Systems Engineer | cStor

NCIE SAN ONTAP, Data Protection

[TMADOCTHOMAS]

Thanks Bob. So just to be sure I understand, are you saying I only need to add ONE destination aggregate from the HA pair, as seen below:

lun mapping add-reporting-nodes -vserver <vserver> -path <Server_Name>* -igroup <Igroup_Name> -destination-aggregate <aggregate_on_node_3_or_4>

.... or, should I add both aggregates on one command line as seen below:

lun mapping add-reporting-nodes -vserver <vserver> -path <Server_Name>* -igroup <Igroup_Name> -destination-aggregate <aggregate_on_node_3>,<aggregate_on_node_4>

[bobshouseofcards]

You need only add the one aggregate.  The idea behind adding an aggregate is to add the aggregate where you are going to move the volume that contains the LUN.  

ONTAP knows that both nodes in an HA pair could potentially own that aggregate (either through failover or through manual aggregate relocation) so both will be set as "reporting" nodes.  Obviously only one will be an optimized path at any given time, but paths to both nodes become available.  

You can see the results immediatly if you use the command lun mapping show -field reporting-nodes with SVM and LUN qualifiers before and after the "add".

Running a second "add" to target an aggregate on the HA pair is not needed but it also doesn't hurt anything.  It's just redundant in that both nodes of the HA pair are already added by the first command.

Hope this helps.

Bob Greenwald

Senior Systems Engineer | cStor

NCIE SAN ONTAP, Data Protection

Kudos and accepted solutions are always appreciated.

[TMADOCTHOMAS]

That answers my questions, thank you again Bob. This has been a very helpful thread!

[bobshouseofcards]

Always forget about that on the remove (since I rarely do myself).

Thanks for the clarification!

Bob Greenwald

Senior Systems Engineer | cStor

NCIE SAN ONTAP, Data Protection

[TMADOCTHOMAS]

Bob,

Really appreciate your comments, they are helping a lot.

I had intended to leave all four paths available, just in case for some reason I needed to move a volume/LUN back to the original nodes. Would you recommend against that?

If I do remove the original reporting nodes, and follow the sequence "add new/remove local/move volume", won't that break the existing volumes/LUNs since they will not be on reporting nodes anymore? I may not be understanding the role of a "reporting node".

Here are my thoughts on the syntax I need. Does this look correct?

lun mapping add-reporting-nodes -vserver <vserver> -path <LUN_path> -igroup <Igroup_Name> -destination-aggregate <aggregate_on_node_3>

lun mapping add-reporting-nodes -vserver <vserver> -path <LUN_path> -igroup <Igroup_Name> -destination-aggregate <aggregate_on_node_4>

Lastly: for the <LUN_path>, can I enter a * wildcard character at the end of the volume name to make it cover any volume/LUN starting with that volume name? In other words:

Can I do this: /vol/<servername>*

Instead of this: /vol/<servername>*/<servername>*.lun

(or will either work)