The wiki article is for 4.5.X.
From what I remember, I did :
- setup new server with 64 bits OS
- setup a dummy install of ZCS 64bits on new server (same release than old server)
- rm -rf /opt/zimbra/ldap-data on new server
- dump LDAP data to ldif file on old server (see wiki)
- stop ZCS on both servers
- import LDAP data from ldif file on new server (see wiki)
- on new server, copy /opt/zimbra/openldap-data to a safe place (outside of /opt/zimbra)
- rsync /opt/zimbra from old server to new server
- shut down old server
- on new server copy /opt/zimbra/openldap-data from safe place to standard place
- "upgrade" ZCS to ZCS 64bits on new server (same release, run "./install.sh -s")
I read all I could find on the subject and the best info I got were John's posts in this thread :
Problem With Moving ZCS to New Server
I don't remember exactly when/how I stopped ZCS on the two servers (and halted the old server). I remember you have to be carefull with your hosts file in new server (as usual) or you can not import ldif data.