port upgrade

[Terry Barnum]

Is there a best practices way of upgrading ports? As a relatively new macports user, I've been reluctant to upgrade postfix and dovecot on my production server for fear of something breaking.

Another macports-user suggested to me several upgrade techniques of varying paranoia levels so I'm wondering what other people do for critical and interdependent software like postfix? (port installed postfix shows @2.6.2_0+darwin_10+dovecot_sasl+mysql5+pcre+tls) Does a port upgrade postfix always do the right things?

Has anyone used TimeMachine as a way to replace the /opt directory in an emergency? 

Thanks,
-Terry