We have a number of Unity Connection 7.1.3 clusters (pub and sub) and all are configured to complete a daily back up of the database and greetings_voicenames. However, when I look at the back up history I see that some sytems are backing up daily (all set to back up daily at 0600) and some systems skip a few days (random number of days). I'm assuming that there is something that triggers the back up like a change to the system database etc. but I've looked through several docs and cannot find anything on this. I want to know if this is expected (and what the triggers are) or if I have a problem. Any advice would be great.