Forum OpenACS Q&A: Re: Checklist for moving an OpenACS site from one host to another
Redirect should be simple at the topmost level (the maintenance page). A little more difficult would be to rewrite and then redirect deeper requests. I haven't used aolserver's rewrite capability so I can't say what it would look like.
Disclaimer: I haven't actually tried this with aolserver and openacs, but it should work...
Good point, it is just a simple filter that does a fully qualified redirect using the IP of the new service, and the path plus query. Unfortunately it only works with one service, if you do virtual hosting, it will not work.