Our 2013 DAG seems to somewhat arbitrarily activate DBs on other servers and move them from the ones they were active on. In looking at metrics there were no noticeable spikes in RAM/IO/Networking/etc so I'm not sure why there are moving.
I can't find how to audit why databases move and am looking for a log file or powershell cmdlet which may help to troubleshoot this.
For clarification, simplifying things a lot: Server 1 has DB1 active Server 2 has DB2 active Server 3 has DB3 active
Each server has passive copies of the other two databases. Overnight, for no apparent reason things will move and look like this:
Server 1 has DB1 and DB3 active Server 2 has no DBs active Server 3 has DB 2 active
Thanks for any help!
PS: In case anyone is dealing with this and wants to stop it at the loss of some features (ie autofailover) consider using the following policy on each server you want to stop autofailover on:
Set-MailboxServer -Identity EXSRV01 -DatabaseCopyAutoActivationPolicy Blocked
Where EXSRV01 is replaced with the name of the Exchange server to stop autoactivation on.