Failover Cluster question

Question

Hello everybody, I was curious if anyone has ran into this issue with Failovercluters.. We have a 2 node and a file share witness set up with a cybernetics SAN through ISCSI.

The power went out so both nodes went offline for a while and after the reboot, are unable to see the cluster by name or IP. The Nodes host virtual machines that need access to the cluster storage to power on.

All nodes and witnesses can ping each other by name and IPS. In the failover cluster manager, both nodes are running and the status of the cluster is up. However when i try to connect to cluster it fails with "Cluster [cluster name] not found" error.

We have DNS and DHCP setup on the backup domain controller but the cluster seemed to have disappeared completely. My theory is that the backup DC doesn't have an a entry for the cluster and the node cant resolve it?

Any suggestions or recommendations on the next steps would be greatly appreciated.

Answer 1

Hi

this sounds like either Domain Controller replication issues and/or DNS resolution issues.

As you reference your backup DC, it suggests that the Primary is a VM on the cluster. Use Repadmin and DCDiag tools to check last replication times and if there are any failures.

You say you can ping using both IP (makes sense) and name - are the names cached entries? Try running nslookup and specify the backup DC as your DNS for resolution. See if it can resolve the Cluster Nodes and Cluster FQDN.

Not sure what DHCP has to do with this - I assume you have static addresses on both your Cluster nodes and your Cluster VIP?

Hope this helps,

Thanks

Michael Durkan

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Answer 2

Hey,

In the failover cluster manager, both nodes are running and the status of the cluster is up.

You see your nodes in failover cluster manager, so you can connect to the cluster. You can see status of the nodes in the cluster only when you connect to the cluster.

In any case, you should verify that your DC has accounts and computer objects needed. https://learn.microsoft.com/en-us/windows-server/failover-clustering/configure-ad-accounts

As noted, you should check replication health of your backup DC>

In addition, you can consider using StarWind VSAN to have redundant iSCSI storage for your cluster. It will create replicated shared storage, which can be used in the cluster.
Cheers,    
Alex Bykovskyi    
StarWind Software    
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