I’ve been a loyal OH user for many years. My skills are totally homegrown, IT is not my profession but is definitely my obsessive hobby. I have a core automation/alarm panel (Omnipro) that I try to use for any heavy lifting/must always work type stuff and then use OH to bridge enhanced functionality my board won’t support, like controlling my mix-mash of multimedia devices, z-wave (thank you @chris) and provide push notifications to our cell phones for various happenings around my house.
I will say that I have only had a handful of “melt-down” moments using snapshots and I just had one happen July 3rd when I updated to snapshot #1630. Suddenly, at 10 pm, during what I routinely do many times during the week, my OH system decided to crap the bad news out via the logs. Something wasn’t working and no real (obvious) clue as to what was now broke. I backed up my conf folder (only 
) and proceeded to install, reinstall, purge, revert to previous snapshots, all without success. This lasted until well after midnight and (after many bad OH dreams) I awoke to continue working to get my system up and running again.
Under normal circumstances, I know the routine and what to save, however, time pressures mounted because my wife and I were hosting the neighborhood 4th of July party with 50+ guests expected to show midday the next day. I wanted my remotely located HDMI switch, Onkyo receiver, and 6 zone audio amp to work with my Harmony remote and LG televisions as well as show off my fancy colored Milight LED’s (thank you @matt1) and my guests to be in awe of my fancy house.
I did eventually get up and running about 30 minutes before my guests arrived by reverting back to 2.5M1 but (because I didn’t do a proper back up) I had to rebuild all my channels and Paper configurations manually. The big loss for me, however, was I neglected to back up my Habpanel.config which, for some frustratingly unknown reason, resides in the bilges of the OH user settings and not the conf folder with everything else. I’m willing to do all the other set up for a fresh install but that one file…it’s always that one file…
I share this with all of you because I do think it would be helpful to have a snapshot status page on the forum for the developers to report (known) breaking changes and let those of us who don’t live in the IT world by trade have some obvious place to go look for issues before we make a plunge. I do scour Github daily to try to see what changed, but breaking changes are at best cryptic in a hidden Github issue or pull request and not easy to determine until actually making the plunge to upgrade.
I think it would also be helpful if someone could share a layman’s version of how to set up a Git repository and/or some other backup strategies that are tested and proven. Obviously, backing up via the OH CLI would have been the smart thing to do, but I’d be interested in figuring out a strategy for having a test and production environment set up and how others manage devices like z-wave sticks with the two environments.
End of the day, I am super appreciative of the OH developers and community as I am constantly learning (and plagiarizing) something off this forum (thank you @rlkoshak, et al). I will say, however, I think we are missing basic information for snapshots. This is the first place I go when I have problems like this and this time I appeared to only have two other users reporting an issue with 1630 but no real idea as to what changed in 1630 that I should have been cautious of before upgrading.