Long shot I know, but does any member understand DAG config for exchange 2013.

 

I have a DAG consisting of three servers, all three servers up and running fine.

 

For some reason the active database keeps moving between a selection of these servers automatically, I would like the active database to remain on the server I created it on and only move around in the event of loss of the active database.

 

For example (assuming 10 databases), I create 5 databases on one server and 5 on another. Then I replicate the databases on the other server, replication succeeds and all is good. Come back a few days later and see that the active databases are now nothing like they were, and one server might have 7 and the other 3, and it keeps changing around. In each case the replication state is good and there are no issues.

 

How can I stop them moving the active database, I've got 1200 mailboxes to distribute between these databases and this is playing havoc.

I am not sure what is going on, looked at the event logs and the databases are coming up as unexpected dismount. This is multiple databases dropping, and the mailboxes I am trying to move are currently empty.

I must admit exchange isn't something I'm particularly familiar with. But we've seen similar issues with the NIC configuration not quite being right and heartbeats dropping out.

Not 2013 but have done with 2010. Are they all on the same LAN or in different sites? Which server is the master?

I've got some powershell scripts to check where the active copy is and email if it's not where it should be that may help pinpoint a cause.

I cracked the problem in Friday, simply by increasing the DAG timeout values to their maximum. The problem is I think that one of the boxes is on the other end of a WAN link and during the data transfer across the link the DAG was losing sight of the other end as the link became overloaded with data. Now moved 700 mailboxes across 10 databases with no problems, next is to start user migration.

The PAM is currently on a remote server, I need to move to local which I'll do on Monday now I've relocated all the mailboxes.

Edited 12 December, 201510 yr by mannyo