Hey, me first (and hopefully not last) posting is to diskuss a Upgrade and Server-Move-Project.

The Situation:
A Ubuntu 08.04 LTS running (decidated server)
Installed zcs-5.0.11_GA_2695.UBUNTU8_64

A Ubuntu 10.04 LTS virtual-Server (via kvm over a new decidated server)
Installing zcs-7.1.1_GA_3196.UBUNTU10_64.

My Sources:
Backup OpenSource Zimbra
Moving Server
OS Specific Upgrade

The Plan:
Step 1: Setting down the TTL-Times for all MX-Records of the Domains showing to Zimbra (about 600 Seconds should be enought)
Step 2: BackUp the Installation on the old Server (50GB data, needed around 2,5 - 3 hours)
Step 3: Upgrading to zcs-7.1.1_GA_3196.UBUNTU8_64

Version 1:
Step 4.1 Install zcs-7.1.1_GA_3196.UBUNTU10_64 on New Server
Step 5.1 Move /opt/zimbra from old Server via rsyn or nfs to new server
Step 6.1 Run zcs-7.1.1_GA_3196.UBUNTU10_64 upgrade again (cause old SErver data is zcs-7.1.1_GA_3196.UBUNTU8_64)

Version 2:
Step 4.2 Dist-Upgrade old Server to Ubuntu 10.04 LTS
Step 5.2 Run zcs-7.1.1_GA_3196.UBUNTU10_64 upgrade
Step 6.2 Move /opt/zimbra from old Server via rsyn or nfs to new server

Step 7 Changing DNS-MX-Records to new IP while the old server is down and the data is moving to the new server.

Because the old server would be shutdown after the servermove I like Version 1 little more , but I dont know if it will work correctly...

Some Questions:
- Which Version (1 or 2) is the saver way for my userdatas?

- I did the Upgrading-Process to Step 3 already, but had some troubles with logger and statistics. Loggerproblem is solved (uninstall syslog install rsyslog), sysstat-problem is not solved yet. Rest running correctly. Should I repair the stats-problem now or can I hope that the next steps would fix that problems?

- Are there some fails in my plan which I havent seen yet?
- Are there some more resources for my problem available i've not listed above which I should read before?

Thanks for your inputs