I'd just like to thank everyone who took the time to write up the helpful and thorough information in the Wiki and Zimbra Blog, which was heavily used in our upgrade/migration.
Everything went relatively smoothly except for a few white knuckle experiences.
It was a busy Easter weekend for me......
6.0.8 -> 6.0.12
Moved from physical host to VMWare ESXi guest:
Ubuntu 8.0.4 x64 -> 10.04 x64
Changed hostname (for silly reasons):
mail.olddomain.com -> mail.newdomain.com
6.0.12 -> 7.1.0
Number of accounts: 134
Mail data: 250GB
Everything upgraded without any problems except that we had some issues with our certificates where the subject CN is mail.olddomain.com and the issuer domain is for mail.newdomain.com. I'm not sure if this will be a problem in the long run but everything appears to be working fine and we don't use the certificates publicly.
Thanks again for a wonderful product!!