Should Cluster Core Resource server go back online automatically?

Question

In the Failover Cluster Manager Console, should the Cluster Core Resource (the name of the Exchange ‎DAG) automatically go back to Online after the Witness Server is restarted?‎

I have two Exchange Mailbox servers and one witness server (not an Exchange server) in a Database ‎Availability Group (DAG). When I restart the witness server, the Cluster Core Resource server (in the ‎Failover Cluster Manager) stays in an “Offline” state until I run “Get-ClusterGroup “Cluster Group” | ‎Move-ClusterGroup –Node name-of-dag”.
‎
‎ Note – I understand the witness server in this scenario is strictly used for quorum and I’ve verified the ‎‎“Offline” state does not affect replication health. I am most concerned with quorum. I am trying to avoid any problems in the event the ‎Cluster Core Resource server does not come back online, someone forgets to run “Get-ClusterGroup ‎‎“Cluster Group” | Move-ClusterGroup –Node name-of-dag” and one of the two Exchange Mailboxes in ‎the DAG fails.
Please advise. ‎

Answer 1

You can reboot a DAG witness server but only if your DAG cluster is operating with all of its members online.

An FSW (file share witness) will only come into play during a failover scenario. This means that it will become a problem if a DAG member fails at the exact same moment your FSW is rebooting, because the remaining DAG member will then not achieve majority, causing the cluster to fail completely.

Note that if you reboot the FWS often in a short period, the cluster will mark the FWS as unreliable and fail the cluster. In that case, you should manually bring it back online by running the following PS cmdlet on a DAG member:

Get-ClusterResource | Start-ClusterResource  

If you only reboot the witness server once and it showing offline, it's not normal, try setting another witness server.

Or you can also enable dynamic quorum: https://social.technet.microsoft.com/wiki/contents/articles/32325.exchange-2013-how-does-dynamic-quorum-work-for-a-two-node-dag.aspx

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