how to organize profiles for test-environment?

[to...@gi-de.com]

Hi, 

for the definiton of our test-environment the integration-tests need to 
run on, I´m thinking about using profiles.
What is best practice to organize the test-environment in profiles?

- defining a parent pom.xml containing all profiles makes the build 
dependant on that environment - if environment will change, all modules 
need to be changed....
- defining the profiles in each pom.xml of each integration-test module 
will blew up the "pom.xml code" and result in a lot of redundant 
information.
- defining the profiles in a profiles.xml is an option, but how to share 
that profiles.xml among all projects? I couldn´t find an option to define 
an alternate profiles.xml location.

Is the global settings.xml the solution for that? But how do I handle 
branches and parallel releases, working with the same Maven version than? 
Another profile for each release?

mvn clean install -Pdb2,testsystem1,v181 ?

Thanx for some "best practice" hints, 

torsten