The problem is to transfer the changes in the development system to the real system. Notice that we wound have done a 'make distclean' and done the diff against the working tree itself, but rebuilding is very time consuming for a big server, so we copy them to a different directory first. We maintain the source tree on a CVS for obvious reasons. This is a very rough outline of the process. There are many other details I didn't go into.
Feedback is welcome.