We are in the process of migrating accounts to our new Exchange 2010 environment, which consists of four servers, two CAS/HUB servers and two Mailbox servers in a DAG. One of the mailbox servers is our production server and the other server is for DR and is located in our DR site. For some reason all four databases ocassionally get mounted on the DR server. I assume this is because the servers are in a DAG, but would databases move themselves when there's nothing wrong with the server they were mounted on? I don't want the databases moving to the DR server automatically.
I know I can use DAC to prevent databases from mounting but I'd prefer not to. So basically my question is why would databases move to the other server and is there a log file or event that I can check (I've already found event id 2090, which doesn't appear to help as it doesn't show an event for the databases switching when they did) to see when they moved to see if infact there was something wrong with the production server.
Thanks!