No, nobody has successfully run a Zimbra installation of nontrivial size for a nontrivial period of time with /opt/zimbra over NFS. index and db are guaranteed to perform poorly and break eventually.
store, maybe, but I don't see the point. iSCSI works fine, and most NAS heads support iSCSI, too.
If you require a mail system that deals with NFS issues, look for a maildir derivative. UW-IMAP, Cyrus, and most commercial email packages just say no. There exist carrier-grade email systems that are designed to work as load-balanced clusters over NFS, but the tend to be feature-limited. |