AlwaysOn availability group DR failover with Powershell I am setting up AlwaysOn availability group for Disaster Recovery (DR) in the test environment. For AG1, node1 and node2 (synchronous commit/automatic failover) are in DC1; node 3 and node 4 (Asynchronous commit/manual failover) are in DC2 and file share witness is in DC3. When DR event occurs, 2 nodes in DC1 will be gone. Since DR nodes are set up as an Asynchronous commit, AG status is resolving. I will need to failover manually to bring AG group to a synchronized state. I want to use powershell to do failover with data loss. When I run the following powershell to failover, I am getting the error.
Switch-SqlAvailabilityGroup -Path SQLSERVER:\Sql\SQLDRPOCA03\DEFAULT\AvailabilityGroups\SQLDRPOCAG


Switch-SqlAvailabilityGroup : The availability replica for availability group 'SQLDRPOCAG' on this instance of SQL Server cannot become the primary replica. One or more databases are not synchronized or have not joined the availability group.
If the availability replica uses the asynchronous-commit mode, consider performing a forced manual failover (with possible data loss). Otherwise, once all local secondary databases are joined and synchronized, you can perform a planned manual
failover to this secondary replica (without data loss). For more information, see SQL Server Books Online.

Is it possible to use powershell to do manual failover?
I think what you are trying to achieve via powershell is for planned manual failover as mentioned in msdn link.  here

A planned manual failover is supported only when the primary replica
and the target secondary replica are running in synchronous-commit
mode and are currently synchronized. A planned manual failover
preserves all the data in the secondary databases that are joined to
the availability group on the target secondary replica

And what you exactly are trying to achieve &quot; failover between async replicas &quot; is more of forced manual failover with/without data loss which can be achieved via TSQL as mentioned in same msdn link. I don't see PS there but may be someone here who have used can answer. I am not sure but may be you can check dbatools if it provides one
Go through the steps as mentioned laster in that article

Manual failover without data loss
Use this method when the primary replica is available, but you need to
temporarily or permanently change the configuration and change the SQL
Server instance that hosts the primary replica. To avoid potential
data loss, before you issue the manual failover, ensure that the
target secondary replica is up to date.