Forum Discussion
Exchange 2019 Failover with DAG Question
Neill Yes we have a witness server, its on the same system as the non-Exchange server for the DAG
So the FSW is on AN Other server which isn't an Exchange server, isn't a DC and is in the same AD domain?
1. Check that the domain Exchange Trusted Subsystem group is actually in the local admins group of the FSW. This catches a lot of people out. e.g. It might be set via group policy or some sort of security scanning util might take it out as not being an approved group.
2. Run Get-DatabaseAvailabilityGroup command and make a note of the FSW directory, on the FSW check if this folder exists and that there are files in it
3. Check that there are no firewalls between any of the 3 servers, especially on port 445
4. If for some reason you are using Windows firewall on the FSW check that it is using the domain profile. I've seen cases where Network Location Awareness sets the wrong profile and thus blocks traffic.
NT
The FSW is its own dedicated server, is not one of the Exchange servers and isn't a DC, and is on the domain.
Following through the checks that you provided:
1. It does have the Exchange Trusted Subsystem in the local admins group
2. I had to use the web interface to get the file path from the FSW. I found that only one of the Exchange servers have the path to the Witness directory physically on the system.
3/4. Firewall and Network settings are good
So based on this I think that my DAG isn't configured quite right. From the web interface I can open the DAG settings and do see the Witness server in the correct field with the directory path. Again, the directory is only present on one of the Exchange servers and not the FSW server. The DAG members does show the 2 Exchange servers listed as well.
Where do I go from here? I apologize for the questions, this was originally set up by a consultant months ago and the actual person is on another job so has limited availability to follow up with.