I need to migrate zimbra from version 4.5.6 on 5.0.18 (both are the open souce edition).
The old version of zimbra mail server is on ubuntu 6.06 LTS and I want to also upgrade server on ubuntu 8.04 LTS. I was reading a lot documentations about migration but I'm not completely sure what is the best solution for this migration. I've been installed new version (5.0.18) and everything working fine, but I'm not sure about backup and restore of mysql database, ldap, stores, indexes, configs etc.

Any suggestion or advice?

Thanks & Regards