I seem to recall reading a long, long time ago that it wasn't supported running recent versions of EPiServer CMS (from 7 and up) on the same server as CMS 6.0.
Does anyone else remember reading anything about this, or have any experience with this?
I guess you are thinking about the problems with the indexing service.
Other than that it should be no problems running the cms 6 side by side with newer versions.
Read more here: http://world.episerver.com/documentation/Items/Upgrading/EPiServer-CMS/7/7/Pages/Upgrading/
Yeah, that was probably what I was thinking about. Not really a problem then since the old site doesn't index any files.
Thanks for your reply! :)