I am running Zimbra 6 FOSS and looking to migrate to Zimbra 7. At the moment, I have two separate Zimbra installation (office-1.com and office-2.com having historically separate domains and infrastructures) and we're using to migration opportunity to merge both domains into a single installation domain (company.com) with two mailbox servers in a multi-server setup.
Can someone outline the steps to follow to perform such an import ? I could install new servers and import existing users and mailboxes, but it would require migrating the storage and it would force a longer downtime than I'd like. Is there a way to do that by upgrading/reconfiguring the existing installation?
Thank you in advance.