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Error When Decommissioning Exchange 2013 Database Availability Group

By July 23, 2019September 23rd, 2020Blog, Exchange, Microsoft
Exchange Availability Group decommission error

I recently encountered this error when decommissioning an Exchange 2013 Database Availability Group.

“Database availability group server EXCHANGESERVER cannot be removed from database availability group DAG since it is currently set for datacenter activation mode and it requires at least two mailbox servers.”

database availability group decommission error

If we try to remove the Database Availability Group in PowerShell we get errors also.

[PS] C:\Windows\system32>Remove-DatabaseAvailabilityGroup -Identity DAG

You can use the Remove-DatabaseAvailabilityGroup cmdlet only on empty database availability groups. There are 2

servers in the group. You can use Remove-DatabaseAvailabilityGroupServer to remove the servers from the database

availability group.

    + CategoryInfo          : InvalidArgument: (:) [Remove-DatabaseAvailabilityGroup], RemoveDagNeedsZeroServersExcept


    + FullyQualifiedErrorId : [Server=CFEMAIL,RequestId=b8c4bfe6-52ec-4406-ace3-81621f0970b3,TimeStamp=12/18/2018 5:11

   :05 PM] [FailureCategory=Cmdlet-RemoveDagNeedsZeroServersException] 91B4AE63,Microsoft.Exchange.Management.SystemC


    + PSComputerName

database availability group decommission powershell error

The error itself makes sense given that the purpose of an Exchange DAG is high availability. Exchange is trying to prevent us from reducing or impacting that high availability.


From an Exchange PowerShell, we run the following command with the correct name of our Database Availability Group. In this case our Database Availability Group is called DAG

Set-DatabaseAvailabilityGroup <Database Availability Group Name> -DatacenterActivationMode Off

exchange powershell command for database availability group

We can now remove each of the Member servers. I recommend removing them one at a time.

remove member servers from group

remove server from database availability group loading

member server removed

Now that there are no longer any member servers in the Database Availability Group, the DAG can be removed.

Exchange Admin Center delete group

Exchange Admin Center Warning messageWe can now proceed with uninstalling Exchange from each of the Exchange servers.

Uninstall exchange from exchange servers

Lucas Guth, PEI


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