Hello and good day.
I am planning on migrating my production Zimbra server (Debian 5 - Zimbra 6.0.8_GA_2661) running on Ubuntu 10.4 32bit to a new hardware box running Ubuntu 10.4 64 Bit.
What would you recommend I do to make this as painless as posible?
I was thinking...

Install 64bit Debian 5 Zimbra 6.0.10 on the new system -> copy over the /opt/zimbra directory from the old box to the new one -> re-run the Debian 5 Zimbra 6.0.10 as an upgrade on the new box

or

Install 64bit Ubuntu (beta) Zimbra 6.0.10 on the new system -> copy over the /opt/zimbra directory from the old box to the new one -> re-run the Ubuntu (beta) Zimbra 6.0.10 as an upgrade on the new box

or

should I do one of the above with Zimbra 7?

or something else that you know will work better?