I am looking into moving my trusted QmailToaster install over to Zimbra. I am testing testing Zimbra on CentOS4.4, but after going through the install and encountering some problems, and then encountering this thread, I am wondering if this is even something to consider.
The problem is not 'why did the upgrade fail', or 'why did /opt/zimbra get deleted'. The real question is 'Why is there user data stored in /opt/zimbra?' The opt directory is storage for large static application and support data. Not user data. Please consult
http://www.pathname.com/fhs.