So I have multiple Exchange 2010 mailbox servers in a DAG configuration. After setting up the passive copies and letting the equipment run for a little while I started getting event id 123 on some of the mailbox servers.
So on "exchmbx01" I have a database mbdb01.
Update-mailboxdatabasecopy –sourceserver exchmbx01 –identity mbdb01\exchmbx01 –network “DagNetwork01” –catalogonly
If you don't specify the identity fully of the database copy Exchange will not know which DB copy you are attempting to update the catalog of.
