Advise on OH 2 > OH 3


Looking for some advice in terms of the best way to migrate from OH2.5 to OH3.1

The easiest way I can see it to do a upgrade from my current system the problem I have ran into is I currently have all my devices are working off the old version of MQTT 1.6 :sob: and this clearly won’t work in OH3

So I thought start from a fresh install and after spend some time playing around with the new OH3 it’s taking a long time to set everything up. I have about 50 items from lights to temp sensors etc

My question is what’s going to be the quickest way to update? change all my current items to work with MQTT 2.4 then upgrade my system to OH3 or start completely from scratch or is there another option/ middle ground?

Many thanks

There are a lot of similar posts that you should search/read for a variety of opinions. In general:

  1. You don’t have to use the UI. Your config files (items, rules, etc.) can be copied over and they’ll mostly work. Some of us have done this and then either moved into UI or just kept the text files. There are some breaking changes that can be found in the release notes (make sure to check all release notes, not just the most recent ones). This is the fastest way to update by virtue of requiring the least work.

  2. If you only have one server available to you, then you must update from MQTT 1.x. If you plan to eventually shift to the UI, then you might as well just rebuild them in the UI. If you’re not sure, stick with config files.

  3. If you have a second server available (e.g. a spare RPi), you can keep your old system running on OH2 and then connect to it using the Remote Binding, which is intended exactly for people who need bindings that aren’t supported in OH3. But then you just have to figure out how the Remote Binding works…and that’s probably more effort than figuring out the new MQTT syntax.

Personally, I started a clean OH3 using the openHABian image, then copied over my text files from a backup. And then I used the UI import feature to move some (not all) of them into the UI. It didn’t take more more than a few hours, and I have 150+ items (including MQTT). I haven’t moved any rules, as I’m content with DSL in .rules files.

It is not that difficult to use the remoteopenhab binding. Items in OH2 appear in OH3 so they can be linked to OH3 Items.

Would you say that’s more or less effort than figuring out MQTT syntax? I’m guessing since I didn’t have to do either of these things.

I just played a bit with MQTT 2 in OH and remoteopenhab was easier.

I do not know if remoteopenhab was tested with OH 2.4. There is now no easy way to upgrade from 2.4 now bintray has been shut down. They pirobably could download 2.5.12 & install manually with the OH2 & OH1 kar files but there is much ugliness there.

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Why isn’t it easy ? Of course nothing was stated about the OPs OS nor the way 2.4 was installed but in case it is

  • a) Linux derivate using apt then it is just a matter of editing the repo location
  • b) openhabian-config ( see a) )
  • c) Linux derivate using tar/zip installation ( using the update script which may require editing the URL inside of the update script )
  • d) Windows based installation ( editing the update scripts URLto point to the new servers location

Am I overseeing something ?

I guess the first step would be to put the OH1 kar file & the incompatible OH2.5.12 kar file in the addons folder. Otherwise the new system cannot fond any addons. I do not know of the incompatible kar file would just be ignored by 2.4.

Off topic, English language is weird :wink:

Overlooking - “I examined it, but did not see that !”
Overseeing - “Hey you, get on with your work !”

Except when we use them in other ways … “My bedroom window overlooks the neighbour’s garden” … “You’ve only given me 9.50, but we’ll overlook that and let you take the 9.99 item” :crazy_face:


The language is very inaccurate and sloppy speakers make matters worse. :frowning:

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I have an Engish degree and have two decades of experience as a writer and communications/marketing specialist. So, I’m qualified to say that English is ridiculous and I feel bad for anyone who has to learn it as a second language.

And now, back on topic as I see @Crs typing as I post this. :wink:


Thank you all for the information something definitely to go look at

Am taking the best option would be to start over using a second PI was hoping their may have been a easier way for someone whos a little unfamiliar with the new system and the ways of working of OpenHAB

Thanks again for all the guidance


The English lesson was a bonus :joy:

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I’d say to just play around with OH3 to get comfortable while keeping OH2 as your production system. OH2 isn’t going anywhere, so there’s no rush to make the move before you’re ready.


Agreed. I am still running 2.5.2 in production LOL