I'd like some advice on the following situation. We've an old Zimbra setup at the office, currently running Zimbra Network Edition 5. It's still working OK but just TOO OLD, I know! But the users are satisfied and Zimbra just works :-)
I need to migrate this setup away, since the machines on which Zimbra runs are getting too old. I want to take this situation to migrate to the new Zimbra 7.
This is our setup:
Release 5.0.16_GA_2921.UBUNTU8 UBUNTU8 NETWORK edition
3 servers (MTA, LDAP, MBOX)
25 heavy users (2GB+) mailboxes, mail, agenda, addressbook, mobile (mostly iPhones)
So how should I be doing this?
I have a possibility to setup a brand new Zimbra 7 environment (using virtualisation) and then move the users over. Or I could just upgrade the current servers and then move over. But it's just that I don't feel comfortable upgrading this old installation and have the feeling "there's no way back" when something breaks. What is a save way to do this?
Some downtime is OK (in the evening or at night) but the next morning all should be working again.
How would you handle this situation?