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diagnose Exchange 2010  DAG fail-over

bominthu asked
Hi Exert,

I have two exchange servers setup in two dofferent AD sites and setup DAG. There was DAG occurred and primary mailbox database was dismounted and secondary mailbox DB was activated. I manually mounted primary DB and it was OK but the next day it occurred again.
I'm trying to check what triggered fail-over. I checked the event logs in server on time stamp before fail-over  happened but i seems event logs error are not related to why fail-over triggered.
Could you please advise me how to check why fail-over started?

Watch Question

Check under
applications and services logs => microsoft => exchange => high availability - operational
filter the log on warnings, errors, and critical events

Also check application logs.



There are some error mentioned about mailbox database
"Failure item notification registration for database 'Mailbox Database 1828675496' failed."
I don't even have that database name in my exchange server.
And there are error logs captured on the day when fail-over happen but all time stamp are after fail-over over.
Any idea?




When I check for critical events in "Fail over cluster manager", I found most are event ID 1069 in both servers. "Cluster resource 'IPv4 DHCP Address 1 (Cluster Group)' in clustered service or application 'Cluster Group' failed."
 I have rest the network state by  unchecking and rechecking "Allow clients to connect through this network" but it didn't help, always server1 or server2 cluster core resource will be offline.

After some checking from Google, I suspect it is due to File share witness?
My File share witness location is in virtual server but server is running fine. Will there be any issue if it is virtual server?

If I would like to move File share witness to physical server, will it effect anything to email?
If no, could you suggest me how can I move File share witness to another server?
Please suggest me something as it is critical issue for me

Thanks a lot