We deploy from a special deployment repository. This has a bunch of advantages: 1) You can revert to a known state. 2) You can see if anything has changed on

We deploy from a special deployment repository. This has a bunch of advantages: 1) You can revert to a known state. 2) You can see if anything has changed on individual servers using svn stat. 3) You have a history of what has changed on production. Any scm would work just fine.