I have an Exchange 2016 on premises DAG. One of the members was fine and was acting as the Active copy for a couple of databases. There were patches to be installed so the active copies were moved to other members. Since then I have been unable to make the member active again. The copy always has a status of Passive Failed. The error generated is:-
The Microsoft Exchange Replication service encountered an unexpected error in log replay for database 'DB01-AU\LFGEXSYD1'. Error MapiExceptionNetworkError: Unable to mount database. (hr=0x80004005, ec=2423)Diagnostic context: Lid: 65256 Lid: 10722 StoreEc: 0x977 Lid: 1494 ---- Remote Context Beg ---- Lid: 59596 dwParam: 0x4BFCBE5 Msg: SM01 Lid: 59596 dwParam: 0x4BFCBE5 Msg: SM02 Lid: 59596 dwParam: 0x4BFCBE5 Msg: SM03 Lid: 59596 dwParam: 0x4BFCBE5 Msg: SM04 Lid: 59596 dwParam: 0x4BFCBE5 Msg: SM05 Lid: 39576 StoreEc: 0x977 Lid: 59596 dwParam: 0x4BFCBE5 Msg: SM06 Lid: 35200 dwParam: 0x1908 Lid: 59768 StoreEc: 0x977 Lid: 59596 dwParam: 0x4C00BBD Msg: SM07 Lid: 59596 dwParam: 0x4C00BBD Msg: SM08 Lid: 59596 dwParam: 0x4C00BBD Msg: SM12 Lid: 35200 dwParam: 0x1908 Lid: 1750 ---- Remote Context End ---- Lid: 1047 StoreEc: 0x977
In Event Viewer I see ID126 regularly:-
At '24/08/2018 2:16:07 AM' the Exchange store database 'DB01-AU' copy on this server encountered an error that caused the database to be dismounted. For more detail about the failure, consult the Event log on the server for other "ExchangeStoreDb" or "msexchangerepl" events. A successful failover restored service.
I was also getting errors about the FastSearch service but rebuilding the indexes from scratch seems to have fixed that.
I have done a fair bit of googling and tried various things such as:-
Rolling back the patches on the server
Suspending the copy and then using Update from the active copy.
Deleting the copy completely and starting from scratch
Removing the member from the DAG and re-adding.
So I'm out of ideas at this point other than a server recovery build.
Any suggestions would be greatly appreciated.