Adding nodes/cluster to a management group - managers?

[Paul Hutchings]

I have a management group comprising 2 clusters:

1x4 node MDL cluster
1x2 node 15k SAS cluster
1 x FOM

We're looking at adding an additional 2 node cluster.

Given that at that point I shall have 8 nodes, how on earth would I configure my managers?

[Jitun]

If it is a single Site, I would remove the FOM and run managers on 5 Nodes.
As Manager is for management in a Management Group, any Node in the Management Group would do.

If it is a MultiSite Setup, run 2 managers each on the 2 sites and keep the FOM on the 3rd Site.

[Paul Hutchings]

It's multi-site with 3rd physical for FOM but with a single VIP across both sites.

My confusion was more over what happens to quorum if we add 2x new 2 node clusters and a node fails in the cluster but neither node on that cluster is running a manager?

[Jitun]

Nothing will happen to the Quorum.
Quorum is a property at the Management Group level.

A node without a manager failing will not affect anything.. except for the volumes if contains.

So if 1 node fails an it has network raid 10 volumes on it, then the volumes will show a warning stating they are no redundant.

Only if the node next to it fails as well.. then the volumes they hold becomes unavailable.


But other clusters are not affected.

[NXS]

sid you create a multi-site cluster or a standard cluster?

[Paul Hutchings]

Thanks John. I think I'd somehow assumed you need to be running a manager on at least one node per cluster, but you're saying the managers (and therefore quorum) are defined and work at the management group?

So what would happen if I added another 2 nodes to my existing management group, configured them as a new 2 node cluster, neither was running a manager, and I then disconnected both nodes?

[Jitun]

Yes Paul, managers (and therefore quorum) are defined and work at the management group.


So what would happen if I added another 2 nodes to my existing management group, configured them as a new 2 node cluster, neither was running a manager, and I then disconnected both nodes?

Only the volumes associated with that cluster would be down, but all other volumes in other cluster would work fine.

You need to make sure max number of managers are able to talk to each other(Multisite Setup)

If I have answered your questions, plz feel free to provide points..