"Drain stopping" an Exchange 2010 CAS array w/o user getting prompts.

The persistence profile timeout determines how long BIG-IP will persist new connections to that node. Any existing connections will not be removed until they are terminated by the client. So if you have someone who's left Outlook open, they are going to remain connected to the same node even though their persistence record has expired.

 

 

Forcing the node offline will not kill the existing connections either, but it does prevent new connections from going to that node, persistence be damned. Again, your client left open will not disconnect.

 

 

Deleting the persistence records won't cause prompts for existing or new connections to the same node, only for new connections to a different node.

 

 

The only way to truly kill all existing connections would be to delete them from tmsh using the delete sys connection command. You might disable the node, delete the persistence entries, and then right before you actually take the server offline delete the open connections to it. Those users will get prompted when they reconnect to another node.