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Database Mirroring Failover Databases Are "Disconnected"


This is 2014
I configured db mirroring with Automatic Failover. So of course a witness server is in place.
I HAVE been able to fail over the database by using tjhe Failover option in the GUI nad fail back That works perfectly.
However when we force a failover by shutting down the primary/principal server,
the database at the mirror server shows "Principal/Disconnected"

Any ideas?


It's because you shutdown the old principal server, so mirroring is now disconnected. That's what you'd expect when only one server is up.

So it worked as expected: the failover occurred, and mirroring is now in a disconnected state. Once you startup the server you stopped, mirroring will reconnect and start sending over the log records. The old principal will now be the new mirror server.


Thanks, TaraKizer. That's good to know. Then it worked as intended.


Tara I have one more followup. We're running on the failover server (formerly the mirror). When we bring up the original principal server, what should I see on the server that is now the principal? What status should the databases show?
This is HA with auto failover with a 3rd server as the witness.


I'm going from memory here, but I believe it'll say synchronized, possibly synchronizing. That's if it was able to catch up. Depending on how long one of them was down, the log file might have grown a bit since it stores the un-mirrored transactions in there.