I run a site on a VPS using Drupal, which I set up & maintain myself (not a 1-click install, in other words). I want to upgrade from Drupal 6 to 7, but I'm anticipating that it'll take a while to get right. So I wondered about setting up another web server on another port, pointing to a different Drupal directory, which I could activate only when I'm working on the upgrade.
Anyone done something like this? Is there a place in the web panel to set something like this up? Or if not, is it kosher to just fire up another Apache instance?