Can I downgrade from 4 to 3.4.x


I have been running 3.4.4 on Ubuntu, installed via apt. I ‘accidentally’ upgraded to 4 (during an apt upgrade) and am now totally broken. Is there a way to revert to 3.4? I’ve searched but come up blank.

I have regular backup using openhab-cli so if I can revert I’m back to a working system

Thanks in advance

Hi, don’t know about the downgrade but if you might explain what’s „broken“, we can support you to get oh4 fixed, too. I had also some obstacles. But once I knew how to tackle, it was relatively easy to get everything running as it was before.

You can use apt-cache madison openhab to get available packages and then force any of them to install e.g. apt install openhab=3.4.5-1 openhab-addons=3.4.5-1.
I’d try to debug what’s wrong, though. “totally broken” does not say much but OH4 is mostly compatible with 3 so not unlikely to revive your system once you find a reason.


Hi. Thanks for getting back. As soon as the rule engine starts I get the message

[] - The queue for a subscriber of type 'class' exceeds 5000 elements. System may be unstable.

in the log a few nudred times a second. There’s nothing else in the log, and the log files fill up so quickly they are rolling over in less than a minute. The system is running, but it’s so busy dealing with whatever it is I might get a light come on five minutes after I throw a switch. I spent an hour or so searching and did find references to similar problems but they were mostly in 2.x builds, nothing relevent.

This has a ‘not going to be fixed quickly’ feel to it and whilst I’m happy to get it going I’d rather do it on a spare rig and have a working system, especially since I don’t have a lot of spare time at the moment.

This system has been migrated from 1.x to 2.x to 3.x and is entirely configured by files, and not much help in the logs!

Thanks - after removing and purging openhab and java17, reinstalling zulu11 and openhab 3.4.5-1 I was able to get my backup restored and running. It’s made me very aware of how dependent we’ve become on home automation!

I’ve been meaning to rebuild my server , Ubuntu 18.04 is getting on a bit. I’ll start fresh on a spare machine and install openhab4 on that, restore my backup and start working on the issues :wink:


Consider moving to a Raspi. Way cheaper spare, easier and faster to restore. Use mirroring.

Actually I started out on a Pi, but with a Freenas file & media server and various SBCs running RTL-433, Zigbee coordinator etc it made sense to move the whole lot to a full fat PC - of course the Pi didn’t have the grunt then that it does now. The next iteration is using a mini PC, with a 128GB ssd, 8G of memory, 4 USB 3 ports, GB ethernet, wifi in a box not much bigger than a Pi case for 99GBP seemed like a no-brainer, the Pi costs that once you factor in the SSD. Add a DAS enclosure with 2 mirrored 12TB disks, job done.

I’m totally lost du upgrade the Java version on my system. I Have a raspberry Pi 4 with openhabian.
Maybe someone has a tutorial.

Wouldn’t a new thread for your question fit better than in this one ?
What os release is installed on your system ( cat /etc/os-release ) ?