I meant I am happy with OH3 in general. I don’t have long-term experience yet. My system runs on a VM, so disk space is not so much an issue when managed properly. For backup, I have a Pi3.
Assuming you run openHABian, you should also deploy SD mirroring so you have another level of protection.
Just chiming in, same issue, and had a full volume. Maybe the jsondb file is truncated before the write of the new version fails due to the volume being full?
It happened again, same circumstances and same outcome. I opened an issue in case it hadn’t been reported previously.
I’ve commented in that issue why I believe you shouldn’t have 
Note it’s just my $.02 I’m no core dev but if so I could and would have closed the issue.
You yourself need to avoid your system runs out of space. It’s impossible to tell from the outside why it did, but on a properly setup system it would not. If you ran (any at least recent version of) openHABian it would take care of logfile rotation so it wouldn’t be OH itself to fill the disk, and for anything beyond OH you’re responsible yourself.
I suggest you reinstall from scratch and also follow the install advices given here and in the official docs to setup mirroring and a backup mechanism to get onto the safe side.
Thanks @mstormi, I think perhaps we are talking about different things? The state of the system volume is definitely the user’s responsibility, and if the volume is full it could well be the user’s fault. However, the GitHub issue is more about what happens to the JsonDB files when OpenHAB finds itself in that unfortunate condition where the volume is full, regardless of what caused it.
The great news for anyone following this thread is that it should be fixed entirely in OpenHAB 3.3!
But as @mstormi reminds us, don’t forget to make your own backups and keep them somewhere else Having a backup close at hand absolutely saved my day.
It was fixed in February so should be present in any recent milestone, too.
That you can install today already.
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