KB4520266 - FIX: When you change SEEDING_MODE to MANUAL using ALTER AVAILABILITY GROUP, SQL Server 2016 does not cancel the current seeding operations to the secondary replica

Applies to: SQL Server 2016 Service Pack 2SQL Server 2016 DeveloperSQL Server 2016 Enterprise


Assume that you create an Always On Availability Group (AG) with automatic seeding in Microsoft SQL Server 2016. When you try to change the SEEDING_MODE to MANUAL by using ALTER AVAILABILITY GROUP on the primary replica, then you notice that SQL Server does not cancel current seeding operations to the secondary replica.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. 


This issue is fixed in the following cumulative update for SQL Server:
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More Information

To cancel automatic seeding, you can run the following command:
--Connected to primary replica
    MODIFYREPLICA ON 'node2'  
To check whether the latest seeding operation was canceled or still running, you can run the following query against the DMV:
selectcurrent_state, failure_state_desc, * from sys.dm_hadr_automatic_seeding orderby start_time desc


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