I have a Zimbra7 server. I am building a new Zimbra8 server that will replace it. I want to do live & incremental migration from the Zimbra7->Zimbra8 server to minimalize downtime.

My current situation is:

Z7 runs on Ubuntu10.
there is NO nameserver running on the Z7 server.
there IS a full nameserver on the same LAN; Zimbra uses it.
the Z7 server's hostname ~= "zimbra.domain.com".
the Z7 server's IP =
the Z7 server's main domain is "zimbra.domain.com"
the Z7 server's SSL cert is for "zimbra.domain.com"

Forward & Reverse DNS is configured so

dig A zimbra.domain.com +short
host domain name pointer zimbra.domain.com.

And the /etc/hosts on it is localhost.localdomain localhost zimbra.domain.com zimbra
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

It all works this way very well on Zimbra7 and with no problems!

I will set up the new Z8 server on Ubuntu 12 on a machine that is on the same LAN.

The IP address & hostname of the Z8 server must in the end be the same as the Z7 original server, but we cannot have these the same during the Z8 installation and the Z7->Z8 Incremental migration.

My detail questions are about how to do the work with the Z8 server on the same LAN at the same time.

(1) When I 1st setup the machine for the Z8 server on the same LAN, what must be

its FQDN hostname?
its IP address?
the DNS results for its hostname & IP?
the contents of its /etc/hosts?

(2) When I 1st install Z8 on the Z8 server machine, what must be

the main domain I assign to Z8?

Once again its the goal to build and configure the Z8 server while the Z7 server remains in Production and do a fast switchover when most of the works and data transfer is done.