I have had some mixed results with this upgrade. First I made a backup of the /opt/zimbra dir, then tried simply upgrading, that failed, after reading other posts due to some services not shutting down completely. I then tried to upgrade again. It seemed to get further, but it did not complete. I tried a third time that seemed to finish. Not all services would start. I played around and never got the mta to start.
So, through other searches (and frustration) I ended up just simply running install.sh -u to remove my install. I do have the backup of my old 4.5 dir, but...how do I get my old e-mail back into my new install? I guess I could do a new server install and just imap copy over the old folders, but if there was just a easy way to copy from the /opt/zimbra/store..that would be great.