Hi

I have an Exchange 2013 DAG with 2 Servers and created a database "DB01" with an active copy - no issues

After creating a further 9 Databases, the Application Log is full of Errors, repeating every 15 minutes:

4133 Database one datacenter health check failed.

4376 Database one datacenter available copy health check failed.

When I run Get-MailboxDatabaseCopyStatus, all Databases are Mounted and Healthy

When I run Get-MailboxDatabaseCopyStatus | fl the only differences between DB01 and the other Databases are:

DB01

ActionInitiator                       : Unknown

LatestFullBackupTime                  : 31/01/2014 23:17:05
SnapshotBackup                        : True
SnapshotLatestFullBackup              : True

DB09

ActionInitiator                       : Service

LatestFullBackupTime                  :
SnapshotBackup                        :
SnapshotLatestFullBackup              :

All Databases have been successfully backed up (Full and Incremental)

Why I am seeing errors for the additional Databases?

Hi shapi,

According to your description, all databases seems to be working smoothly though the issue occurs when Health Monitoring checks. It's look like a cosmetic issue.

Please try to set the DatacenterActivationMode parameter to off by using Set-DatabaseAvailabilityGroup cmdlet to turn DAC mode off and check whether the issue persists. Here is a similar thread about this issue:

http://social.technet.microsoft.com/Forums/exchange/en-US/53a90540-dcc3-4bff-8f27-772405c02b63/event4133-database-one-datacenter-health-check-failed-and-event4376-database-one-datacenter

Thanks,

I have seen that article and turning off DAC mode does indeed stop the errors.

However, DAC mode is an important part of DAG management and I would like it enabled!

It is also hard to ignore a "cosmetic issue" when the Application Log is so full of Errors.

I agree with Rinken, on the other thread, that this is a bug - so do I report to Microsoft and request a fix in a future release?

Hi,

It is a known issue for Exchange 2013 that these two Event IDs 4133 and 4376 are harmless and can be safely ignored.

For the two errors to be logged, it fills the following conditions:

1. There is a DAG that is hosted in one Datacenter, with databases replicated between nodes; (in our case, they are in the same AD site)

2. The DAG must be setup in DAC mode.

By disabling the DAC-Mode setting, it can prevent the Event IDs 4133 and 4376 no longer appearing. If you do not want to remove DagOnly setting from DAC as a workaround, we can keep it enabled and safely ignore the warning.

Thanks,