Start Profile: Changing Instance Services 
Purpose
To start an additional SAP service process on a computer (or delete an SAP service process), you must adapt the start profile accordingly.
Process Flow
You do not want the message server to run on Host A, but on Host B. You must adapt the start profiles for the instances on both hosts accordingly. In this case, the name of the start profile file should end with
_<hostname> .

If you are using a start profile to start several SAP instances, the change will effect all these instances. In this case, the name of the start profile should NOT end with
See also:
Changing Profile Parameters