Moving a messaging engine from one server to another using the HAManager
You can move a messaging engine from one server to another
by changing the policy that is bound to the messaging engine's HAGroup. This is the recommended
way of moving the messaging engine. You must not attempt to directly
activate or deactivate the members of the HAGroup that relates to
the messaging engine.
Managing high availability when messaging engines fail to start
If an attempt to start a messaging engine on a server is
unsuccessful, that server is disabled as a location for that messaging
engine to run. After you have resolved the problem that prevented
the messaging engine from starting, you must manually re-enable the
server to maintain your high availability environment.