As I recently handled a migration from Zimbra 8.7.11 to Zimbra 8.8.12, I’ve been running into things I think the Zimbra updater should handle by itself, and/or things that should be documented in a more practical way than they currently are. I’ll just keep updating this post with things I find and learn.
(The migration turned into an 18 hour job since we ran into a +1 year old problem where an Ubuntu upgrade form 14.04.LTS to 16.04.LTS more or less wipes your Zimbra setup and leaves it in a very sorry state. Fortunately, I managed to piece it back by hand.)
Zimbra Backup NG
The new and improved Zimbra Backup NG should be enabled IMHO. It does things a lot better than the previous version(s). In a number of places, Zimbra makes references to its improvements, and so on. They should probably include this instruction too:
To disable the “classic” (or “legacy”) backups, a simple
zmschedulebackup -F
(as the “zimbra” user) is all you need to execute. (You may want to hang on to your old backups until they’ve outlived their purpose though. This command only disables/removes the scheduled “legacy” backups.)