Suspending and Resuming Data Movement

How to suspend data movement in SQL Server Always On Availability Groups

The process to suspend data movement is the same from primary and secondary replica; however, you need to be connected to the appropriate instance.

Connect to the SQL in SSMS, go to Always On Availability Groups-> Availability Groups-> Availability Databases.

Right-click on the database for which we want to suspend the data movement.

Choose Suspend Data Movement and confirm. Or in T-SQL, on the replica concerned:

ALTER DATABASE [YourDB] SET HADR SUSPEND;

Suspending on the primary stops the log from being reused for every replica, so the primary’s transaction log grows until data movement is resumed (log_reuse_wait_desc = AVAILABILITY_REPLICA). Suspend for as short a time as possible.

Resume data movement in SQL Server Always On Availability Groups

To resume the data movement from the primary to the secondary replica, right-click on the availability group database and click on the Resume Data Movement.

ALTER DATABASE [YourDB] SET HADR RESUME;

Remove from Availability Group (don’t do)

Do not remove databases or availability groups as a fix. The Remove Availability Group dialogue deletes the whole AG, including the listener, for every database in it. Removing a single database (ALTER AVAILABILITY GROUP [YourAGName] REMOVE DATABASE [YourDB]) leaves the secondary copies in RESTORING state, and they must be reseeded to add it back. Both need approval.

From my SQL Server DBA handbook.