I want to start using Zimbra Open Source (on Debian), but I have a question regarding maintenance.
One package that I have experience with that installs outside the OS's package manager, is DirectAdmin. Maintaining that is a big pain, because it's not done with apt. This is especially true when there is a dist upgrade (from etch to lenny, for instance).
How does this work with Zimbra? There are two concerns:
1) When there is a new version of Zimbra, it just tells you to download the entire installer, right? Will that perform a clean upgrade of packages and not reset all kinds of settings? What if the upgrade is major (from 6 to 7, for instance). Will it be aware of version 6 to perform a clean upgrade?
2) When there is a new version of Debian, how is the upgrade done? Should I first upgrade Zimbra to a version that understands the new Debian and then upgrade Debian?